## APHIS Evaluation of the
Classical Swine Fever Status of a Region

in Mexico

O ctober 2013

U nited States Department of Agriculture Animal and Plant Health Inspection Service Veterinary Services National Center for Import and Export

Regionalization Evaluation ServicesEvaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________



## Table of Contents

List of Figures, Tables and Appendices

... .......................................... .............. 3

Abbreviations

... .......................................... ................................ ........................ 4

Executive Summary

... .......................................... ................................ .............. 5

Introduction

... .......................................... ................................ ......................... 1 1

Hazard Identification

..................................................................... .. ... .. 1 5

Release Assessment

................................. ..... .............................. . ... ....... 1 8

Scope of the evaluation

....................................................... . ............ 18 Veterinary control and oversight

.................................................... . . 18 Disease history and vaccination practices

............................................ 23 Livestock demographics

....................................................... . .......... 31 Epidemiological separation from potential sources of infection

.................. 36 Diagnostic laboratory capabilities

................................. .................... 42 Surveillance practices

....................................................... . .............. 4 3 Emergency preparedness and response

.................................... .. ......... 50

Release assessment conclusions .........

............ .................................... 5 1

Exposure Assessment

......... ................................ ...... ..... ............... . ...... 5 7

Consequence Assessment

...................................................... .... ........ . ... 5 9

Risk Estimation

...................................................... ..... ................... . ... 6 3

References

.................................................................................... .. ... 6 4

2Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________



## List of Figures

Figure 1: APHIS Regionalization of Mexico for CSF

............................................ . . ....... 12

Figure 2 : Structure of State Veterinarian Service

...................................................... . ...... 2 1

Figure 3: Epidemiological Status National CSF C ampaign, 2005

........................... . ...... 2 8

Figure 4: Epidemiological Status National CSF Campaign, 2008

........................... . ...... 2 8

Figure 5 : Swine movements into and out of Central Western Region, 2011

...... . .... . ...... 3 3

Figure 6: Swine movements into and out of Chiapas, 2011 ............................................3 5

Figure 7: Phyto and Zoosanitary Quarantine Lines ...................................

. .............. ....... 40



## List of Tables

Table 1: Significant Dates for the CSF Campaign in Mexico

.......... ............................... 2 4

Table 2: Swine Production by State, 2011

. ..... ............................................... . .................. 3 1

Table 3: CSF surveillance sampling scheme, 201 1

.......................... ............................... 4 5

Table 4: CSF surveillance sampling scheme, 2012 .......................... ............................... 4 6

Table 5 : Active CSF surveillance samples with positive findings, 2011

- 2012

................ 4 7

Table 6: Passive CSF surveillance samples with positive findings, 2011

- 2012 ...............4 8



## List of Appendices

Appendix 1 : Certification of the Centro de Palo Alto Laboratory as CSF Diagnostic Reference Laboratory

in Mexico, November 28

- December 1, 2011

......................................................... ..... A

- 1

Appendix 2 : SENASICA Organization Chart

......................................................... ..... A

- 8

Appendix 3 : Mexico CSF Case Definition

......................................................... ......... A

- 10

Appendix 4 : Mexico CSF Site Visit Report: Field Investigations of CSF Suspect Farms in the State of Guanajuato, November 14

- 18, 2011

.................................................. ....... ................... A

- 18

3Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________



## Abbreviations

APHIS Animal and Plant Health Inspection Service

CPA Comision Mexico

- Estados Unidos para la prevencion y control de la fiebre aftosa y otras enfermedades exoticas (Mexico

- USA Commission

for the Prevention of Foot and Mouth Disease and other Foreign Animal Diseases)

CENASA Centro Nacional de Servicios de Diagnostico en Salud Animal ( N a t ional Veterinary Services Diagnostic Laboratory )

CENAPA Centro Nacional de Servicios de Constatacion en Salud Anima l ( N a t ional

V eterinary T oxicology and Parasitology L aboratory)

CFPP Comité Estatal Para el Fomento y Protección Pecuaria de Nayarit, S.C. (Animal Agriculture Promotion and Protection Committee)

CSF Classical swine fever

CWR Central Western Region

DGICA Direccion General de Inocuidad y Calidad Agroalimentaria ( General

Directorate of Agr i food Safety and Quality Control)

DGIF Direccion General de Inspeccion Fitozoosanitaria (Animal and Plant Health Inspection Service General Direct orate )

DGSA Direccion General de Salud Animal ( General Direct orate Animal Health)

DINESA Dispositivo Nacional de Emergencia de Sanidad Animal ( National Animal Health Emergency Operation)

GEESA Grupos Estatales de Emergencia en Salud Animal (Stat e Animal Health

Em ergency Group)

NOM Normas Oficiales Mexicana (Official Standards of Mexico)

SAGARPA Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y

Alimentación (Ministry of Agriculture, Livestock Production, Rural Development, Fishery, and Food)

SENASICA Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria (National Service of Agr ifood Health, Safety and Quality)

TIF Federal Inspection Type Establishments

4Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________



## Section 1. Executive Summary

In November 2007, t he Government of Mexico submitted a request to the Animal and Plant Health Inspection Service (APHIS) seeking recognition of the classical swine fever (CSF) status of the States of Aguascalientes, Colima, Guanajuato, Jalisco, Michoacán, Querétaro, San Luis Potosí, and Zacatecas to allow export of fresh pork and pork products originating in these States to the United States. C ollectively , these States are known as the Central Western Region (CWR) [ 1 ]

. M exico had declared these S tates free of CSF in July 2006 after conducting a CSF eradication campaign. On receiving this request, APHIS initiated an evaluation of the CSF status of the CWR ( see Figure 1 , page 11 )

. In September 2008, the Government of Mexico expanded its request to include

evaluation of the State of Puebla

, which had been declared CSF

- free in December 2006. In 2009, Mexico expanded its request to include all Mexican territory after its January 30,

2009

, declaration that the entire country was CSF

- free.

APHIS technical teams made two site visits to the CWR, the first in May 2008 and the second in Apri l 2012. In December 2012, APHIS conducted a site visit to evaluate the remaining unrecognized States of Mexico. The results of th ese evaluation s allowed

APHIS to decide whether to recognize the disease status and under what conditions to
accept the import ation of fresh pork and pork products originating from additional regions in Mexico.

Supporting documentation reviewed for this risk assessment came from the Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion ( Secretariat of Agri culture, Livestock, Rural Development, Fisheries and Food , or SAGARPA) and Mexican State governments ; observations made by APHIS technical teams during site visits in May 2008

, April 2012

, and December 2012 ; peer

- reviewed articles ; and data from the World Organization for Animal Health (OIE) and other technical sources.

This risk analysis was conducted according to OIE guidelines and therefore includes a hazard identification section, a release assessment, an exposure assessment, a consequence assessment, and a risk estimate [ 2 ] . The hazard under consideration is CSF

virus

.

Release Assessment

Serologic evidence of exposu re to CSF virus has been found in a number of Mexican States. The specificity of the antibodies was demonstrated by comparative neutralization tests; however, no virus has been detected. It has not been possible from the data

available to determine whether these antibodies were produced after infection with a field strain of CSF virus or after vaccination with CSF vaccine. These findings increase the level of uncertainty regarding the presence or absence of CSF virus in Mexico.

APHIS considers three pos sible explanations for the high serum neutralization ( SN ) titers found in the sera of pigs during several active and passive surveillance investigations:

5Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

exposure to CSF vaccine virus; exposure to field strain CSF virus; and false positive test

results.

APHIS concludes that for all of Mexico except Chiapas the most likely explanation for the serological findings is residual vaccine titers and/or continued illegal use of vaccine.

However

, the pattern of findings in Chiapas

, along with its close proximit y to known CSF viral activity in Guatemala

, prevents APHIS from concluding that antibody detection in Chiapas is due solely to exposure to vaccine virus.

Although APHIS is unable to recognize these States as free of CSF due to the uncertainty surrounding the serological findings, APHIS concludes that the risk of importing CSF

infected pork and pork products from the currently unrecognized States of Mexico, with the exception of Chiapas, is low and can be mitigated if certain requirements are met on

the fa rms of origin and in the slaughterhouses and processing plants. These requirements are described below under Mitigations.

APHIS identified three risk factors associated with importing Mexican

- origin pork and pork products into the United States from Mexi co

.

Uncertainty regarding positive serological results

Serologic evidence of exposure in swine to CSF virus has been found in a number of

Mexican States as recently as 2012 . The specificity of the antibodies to CSF virus was demonstrated by comparative neutralization tests; however, no virus has been detected. I t
has not been possible from the data available to determine whether these antibodies were produced as a result of infection with a field strain of CSF virus or af ter vaccination with

CSF vaccine. These findings increase the level of uncertainty regarding the presence or

absence of CSF virus in Mexico

.

Incomplete epidemiological investigations of CSF suspect cases

During the last several years, the National Service of Agrifood Health, Safety and Quality ( SENASICA ) has improved the quality and consistency of field epidemiological techniques and standards. However, these improvements have not been uniform ly implement ed in all areas of the country

. APHIS is concerned about continued problems with the quality of some epidemiological investigations of CSF suspect cases. Specifically, APHIS is concerned about the thoroughness of the investigations and lack

of trace

- in and trace

- out activities of some suspect case s

. In some investigations

, staff

have not selected appropriate animals to sample or have not chosen the most appropriate diagnostic test to run on the samples collected. For example, several cases involved

swine in which high titers to CSF antibodies had previously been detected ; these were selected for sampling to test for CSF antigen and/or vir us isolation long after live virus , if

it had been present, would likely have been cleared from the animal. In general, C SF antibodies are detectable 10 to 14 days post infection (dpi) at the earliest, while the ability

6Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

to isolate virus from tonsil tissue begins declining simultaneously with the appearance of antibody [ 3

- 8 ]. 1

This problem could limit SENASICA’s ability to confirm or exclude CSF virus activity

in accordance with international standards. However

, APHIS acknowledges the ongoing efforts of SENASICA to address this issue, as evidenced by its recent attempts to correct investigation deficiencies.

Proximity t o CSF viral activity in neighboring countries

The existence of common land borders with CSF

- affected regions in the south presents a risk for reintroducing CSF into Mexico. This factor is substantially mitigated because Mexico prohibits the importation o f swine, pork

, and pork products from countries it

considers CSF

- affected, including Belize and Guatemala. However, swine, pork, or pork products could be moved illegally into Mexico . The legal movement of people, vehicles

, or equipment that may be conta minated with undetected CSF virus may also reintroduce

CSF into Mexico.

Mitigations

Because of these risk factors, A PHIS determined certain restrictions are necessary to mitigate the risk of release of CSF virus via fresh pork and pork products originat ing in

and imported from a CSF

- low

- risk region in Mexico

. The CSF

- low

- risk region in Mexico recognized by APHIS includes all of Mexico except the 9

- states currently recognized as CSF

- free and the State of Chiapas for which APHIS considers the CSF risk to be unacceptable. These restrictions will require SENASICA to certify certain conditions on the farm of origin and at the slaughterhouse and processing plants.

Therefore, APHIS proposes to: a) Allow importation of Mexican

- origin pork and pork pro ducts from a CSF

- low

risk region in Mexico

, subject to specified conditions

.

1 The clinical signs and outcomes of CSFV infections vary considerably depending on the strain of virus as well as host and environmental factors. In general, antibodies are detectable 10 to 14 days post infection (dpi) at the earliest. In pigs with chroni c CSF, neutralizing antibodies are detectable at the end of the first month post infection but disappear a few days afterwards [ 3

- 6, 8 ].

Antigen detection is even more variable depending on the virus strain. For highly virulent CSFV strains (such as the Brescia strain)

, animals die within 9 to 14 dpi and virus is detected 2 t o 4 dpi onwards

. However, moderately virulent CSFV strains (like the Haiti strain) can be detected up to 28 dpi in tonsils using the PCR . L ow virulent strains, like the Bavaro, have been detected in blood for up to 29 dpi, in tonsil scraping s for 21 dpi

, and up to 70 dpi in hist o logical sections of tonsil tissue [ 3, 6

- 8 ].

T he times for virus detection in the same samples using the vir us isolation (VI) test proved to be shorter.

Some authors have explained this effect as the result of the formation of virus

- antibody complexes . The VI test may start losing sensitivity simultaneously with the appearance of antibodies , around 14 dpi [ 6 , 7 ].

7Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________________________________________________

b) R estrict imports of pork and pork products originat ing in and imported from a CSF -low-risk region in Mexico into the United States by requiring pork be derived from swine raised on farms that operate under a high level of biosecurity

and where CSF antigen exposure has not been detected

. c) Require pork or pork products originat ing in and imported from a CSF -low-risk region in Mexico be derived from swine not commingled with swine not originat ing from herds operating under the required sanitary standards. d) Require pork or pork products originating in and imported from a CSF -low- risk region in Mexico not be commingled with pork or pork products derived from swine not orig inat ing from herds not reared under the required level of sanitary

standards. e) Apply restr ictio n s descr ibed in 9 CFR 94.32 to pork and pork products originating in and imported f

ro m a C SF -low-risk region in M exico

. f) R equire the establishment slaughtering swine intended for export to the U.S. to

allow periodic onsite evaluation and subsequent inspection of its facilities, records, and operations by an APHIS representative.

A PHIS propos es that SENASICA certify pork and pork products originating from a CSF

low-risk region in Mexico as derived from swine reared on premises meeting the following standards for sanitary conditions and biosecurity and not commingled with swine reared under less stringent standards:

1. H erd is tested annually for CSF and the results show absence of antibodies to CSF. The sampling protocol includes:

a. Serologic testing of the herd, using a testing protocol that allows

differentiation between CSF antibodies and cross- reactions with antibodies to other pestiviruses. Sample size should be adequate to detect

5 percent prevalence at a 95 percent confidence l evel.

b. Samples from the herd may be collected at the slaughterhouse or the farm.

c. Any sick pigs showing clinical signs consistent with CSF are sampled and tested for CSF antigen at any time. Any freshly dead or euthanized pigs are necropsied and complete d iagnostics for CSF performed. 2. Biosecurity measures include:

a. Containment of domestic pigs to prevent exposure to other swine, wildlife or swine products. b. Cleaning, disinfection, and control of movement of vehicles entering farms or transport ing swine.

c. Control of personnel entering the farm and keeping a written visitors’ log. d. Training of personnel and farm veterinarians in awareness of risk of fomite spread and clinical signs of CSF.

e. Recordkeeping of animal movements into and out of the farm (including speci es other than swine).

f. Prohibition of swill feeding on the farm.

g. Documentation of adequate pest control on the farm. h. Prohibition of farm personnel from owning or working with other swine or in swine slaughter facilities.

8Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________________________________________________

3. R eplacement stock and swine semen ar e sourced only from herds of equivalent sanitary status not located in regions considered by APHIS to be CSF- affected or are replacement stock or semen -donor boars that have tested negative for CSF while being quarantined before introduction to the destination farm or semen collection center

. 4. Herds are not epidemiologically linked to CSF outbreaks and have not been located within protection and surveillance zones established in response to CSF outbreaks within the previous 12 months.

5. Herds are inspected annually by SENASICA

, which verifies compliance with the

above conditions.

A PHIS will also propose special restrictions requiring pork or pork products originat ing in and imported from a CSF -low-risk region in Mexico to be derived from swine not commingled with swine originating from herds not meeting these sanitary standards

. The proposed rule will also require pork or pork products originating from a CSF -low- risk region in Mexico for export to the United States to not commingle with pork or pork products derived from swine originating from herds not meeting the sanitary standards

described above

.

APHI S also intends to impose special restrictions described in 9 C FR 94.32 . APHIS

considers M exico to me et t he criteria described i n this r egulation be caus e Mexico s hares

a c ommon land border w ith countries A PHIS do es not r ecognize a s C SF- free. These

restrictions pr ohibit t he i mportation of por k and pork products de rived from s wine originating in or ev er living in regions A PHIS considers CSF

- affected. P ork or por k products m ust de rive f

rom s wine s laughtered at a federally inspected establishment in a region of M exico from w hich pork or pork pr oducts ar e eligible f or export to the U nited

States . Further, the regulation prohibits t he i mportation of por k or por k products t hat might have commingled with or be contaminated by pork or por k products de rived from

swine or iginating in C SF

- affected r egions.

A PHIS concludes the se mitigations will greatly reduce the likelihood that pork and pork products originating in and imported from a CSF -low-risk region in Mexico might be infected with or contaminated by CSF virus.

E

xposure Assessment

A PHIS assessed the likelihood of exposure of susceptible swine populations in the United

States to CSF virus in fresh pork or pork products originating in and imported from a CSF -low-risk region in Mexico . Studies of the U.S. waste- feeding sector led APHIS to conclude susceptible swine in the United States are unlikely to be exposed to the CSF virus via waste feeding

.

C onsequence Assessment

The biological and economic consequences of introducing CSF virus into the United

States could be substantial, although they would likely vary based on the extent of the

9Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

outbreak at the time of detection, the virus serotype introd uced, and movement and demographics of affected swine

. Additionally, restrictions imposed by international trading partners could cause severe economic losses to the U.S. livestock industry.

Risk Estimat ion

In summary, although the consequences of a CSF outbreak in the United States would be

serious

, based on the findings of the release and exposure assessments APHIS believes our proposed mitigations will significantly lower the risk of CSF

- infected pork or pork products entering the United States from a CSF

- low

- risk region in Mexico and exposing

U.S. swine to the disease.

10Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________



## Section 2. Introduction

History

APHIS currently allows the importation of fresh pork and pork products from nine

Mexican States it had previously evaluated a nd recognized as free of CSF [9

- 11]

. Those

States are Baja California, Baja California Sur, Campeche, Chihuahua, Nayarit, Quintana Roo, Sinaloa, Sonora, and Yucatan. Recognition of those nine states was based on conditions that existed at the time they were initially evaluated , including rest r ictions on the movement of live swine, pork and pork products that mitigate d the risk of reintroducing CSF virus into those States . At that time, Mexico regionalized its territory while conducting the National CSF Campaign to eradicate the disease. In January 2009, Mexico declared that CSF had been eradicated and removed all remaining movement controls upon which its regionalization of the country had been based.

In November 2007, t he Government of Mexico submit ted a request to the Animal and Plant Health Inspection Service (APHIS) seeking recognition of the classical swine fever (CSF) status of the States of Aguascalientes, Colima, Guanajuato, Jalisco, Michoacán, Querétaro, San Luis Potosí, and Zacatecas to allo w the export of fr esh pork and pork products originating in these States to the United States. C ollectively , these States are known as the Central Western Region (CWR) [ 1 ]

. Mexico had declared these States free

of CSF in July 2006 after conducting a CS F eradication campaign. On receiving this request, APHIS initiated an evaluation of the CSF status of the CWR ( see Figure 1 )

. In September 2008, the Government of Mexico expanded their request to include evaluation

of the State of Puebla which had been declared CSF

- free in December 2006. In 2009,

Mexico expanded its request to include all Mexican territory after its January 30, 2009 declaration that the entire country was CSF

- free.

APHIS technical teams made two site visits to the CWR , the first in May 2008 and the second in April 2012. In December 2012, APHIS conducted a site visit to evaluate the remaining unrecognized States of Mexico. The results of th ese evaluation s provide d the

basis for APHIS to decide whether and under what conditions to allow the importation of fresh pork and pork products originating from additional region s in Mexico

.

11Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Figure 1

– Map of Mexico

Source: USDA:APHIS:VS:CEAH

12Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

APHIS 2008 Site Visit to CWR

During the two years prior to the site visit, the National Service of Health, Food Safety and Agro

- Alimentary Quality ( SENASICA ) posted the results of Mexico’s national CSF surveillance program on its website. These results included numerous epidemiological

alerts which were listed whenever positive serological samples were detected

. SENASICA was unable to confirm CSF cases related to any of these alerts . APHIS was

concerned that t he number of p ositive samples reported for the CWR exceed ed the number of false positives that might reasonably be expected from active surveillance in a region free of CSF.

An APHIS technical team visited the CWR in May 2008 to evaluate the status of the region and to assess the situation

. The team sought to verify how Mexico excluded circulating CS F virus as the underlying cause for the positive surveillance test results.

Although t he team observed many strong points in Mexico ’s vete rinary infrastructure,

movement controls, and commercial farm biosecurity, APHIS identified critical deficiencies in the CSF surveillance systems, epidemiological follow

- up, and laboratory capacities which introduce d uncertainty in the assessment of SENASICA’s ability to reasonably determine the presence of circulating CSF virus in the CWR

. APHIS

concluded that t he ability to detect CSF virus was necessary to confidently support a

declaration of CSF

- freedom and to quickly detect CSF virus if it were reintroduced into a

disease

- free area.

As a result of these observations, APHIS did not proceed with regulatory action to recognize the CSF status of the CWR

. Under existing APHIS regulations, pork and pork products fro m the r egion were eligible for impo rtation only under the conditions

described in 9 CFR 94.9 (processed in a way to inactivate the CSF virus). Importation of live swine, swine semen, and fresh pork from this region of Mexico continue d to be prohibited due to the risk of CSF.

APHIS Technica l Assistance

During 2011 at the request of SENASICA, APHIS provided technical assistance regarding CSF laboratory diagnostic protocols and techniques, field investigation methodology and surveillance strategy. As a result of this joint effort, Mexico dev eloped a national standard protocol for appropriate laboratory procedures and epidemiologic

follow

- up to positive serological findings utilizing a standardized diagnostic protocol.

In the fall of 2011

, personnel from APHIS’ Foreign Animal Disease Diagnostic Laboratory (FADDL) at Plum Island extensively reviewed SENASICA’s laboratory network and their findings (from training, site visits, document reviews, and proficiency panel testing) were favorable. F ADDL reviewed the BSL3 laboratory at Palo Alto and verified their competency to conduct CSF confirmatory testing with an effective date of Sept. 13, 2011 ( see Appendix 1 ) . APHIS considers confirmatory tests conducted after

that date to be valid.

13Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

In Nove mber 2011, APHIS foreign animal disease diagnosticians accompanied SENASICA personnel on investigations of suspect cases (i.e. positive results on CSF screening tests) in Jalisco. APHIS personnel considered Mexico’s field investigation methodology for the se suspect cases in Jalisco to be acceptable , although deficiencies

were o bserved in other case investigations described subsequently in this document

. However, the presence of CSF virus could not be excluded or confirmed. T he CSF antibody detection in t hose and other suspect cases remain s unexplained ; however, the absence of clinical disease or expansion of CSF antibody detection suggests that either CSF virus had not been present or had been effectively eliminated . FADDL conducted further testing on sa mples received from SENASICA in an attempt to develop a technique to exclude or confirm CSF in these cases

.

APHIS 2012 Site Visit s

In April 2012, APHIS made a site visit to the CWR . This region includes one of the major pork production areas of Mexico. In December 2012, APHIS conducted a site visit to evaluate all remaining unrecognized Mexican States. The observations and information obtained during th ese visit s are described in the following release assessment.

Documentation

Supporting documentation reviewed for this risk assessment came from the Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion ( Secretariat of Agriculture, Livestock , Rural Development, Fisheries and Food, or SAGARPA) and Mexican State governments ; observations made by APHIS technical team s during site visits in May 2008

, April 2012 and December 2012 ; peer

- reviewed articles ; and data from the World Organization for An imal Health (OIE) and other technical sources.

Methodology

This risk analysis was conducted according to the format recommended by OIE and, therefore, includes a hazard identification section, a release assessment, an exposure

assessment, a consequence a ssessment, and a risk estimate [ 2 ] . The hazard under

consideration is CSF virus. The risk assessment allowed APHIS to decide whether and

under wh at conditions to accept the importation of fresh pork and pork products from

additional Mexic an States

.

Application

APHIS previously recognized Mexico as a region in which other swine dise a s e s, specifically swine vesicular disease (SVD) and foot

- and

- mouth disease (FMD), w ere not
know n to exist [ 12 ]

. In addition, APHIS does not consider Mexico to be affected with

African swine fever. CSF is the hazard being evaluated in this analysis.

14Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________



## Section 3. Hazard Identification

The World Organization for Animal Health (OIE) lists several animal diseases that are considered primary hazards associated with trade of animals and animal products. APHIS regulations mitigate the risk of introduction of these foreign animal diseases in to the United States. As such, APHIS conducts an import risk analysis addressing hazard s of primary concern prior to initiating or resuming trade of animal commodities. APHIS considers classical swine fever (CSF) virus to be a potential hazard associated with trade of live swine and swine products. CSF was eradicated from the United States i n 1976.

Causative agent

Classical swine fever, also known as hog cholera, is a highly contagious disease of swine caused by a Pestivirus of the family Flaviviridae [ 13 ] . Only one serotype has been found.

Host range

Natural hosts of CSF virus are members of the Suidae family, including domestic and

wild swine [ 14 ] . Infected swine are the only reservoir of virus [ 15 ] . The role of wild boar

as a virus reservoir and source of infection for domestic swine is well known and epidemiological links b etween CSF infection in wild boar and domestic swine have been reported repeatedly in recent years 16, 17]

.

Incubation period

The incubation period for CSF is 2

- 14 days [ 15, 18]

.

Morbidity and mortality

Four distinct clinical forms of CSF have been described: acute, chronic, congenital, and

mild [ 19, 21 ] . The acute form is characterized by high fever, anorexia, lethargy, and hemorrhagic lesions and cyanosis of the skin. Death occurs 5

- 25 days after onset of the illness; mortality in young pigs can approach 100 percent. The chronic form, seen primarily with less virulent CSF virus strains or in partially immune herds, presents as fever, dullness, growth retardation, and diarrhea for up to 1 month. Pigs often appear to recover only to relapse and die within about 3 months. Depending on the virulence of the

virus s train and the stage of gestation, the congenital form can present at fetal death, resorption, mummification, or abortion. If born alive, the piglet may exhibit congenital tremor, weakness, and/or poor growth leading to death. Conversely, piglets may be bor n clinically normal but persistently viremic with intermittent virus shedding (no antibody response). The mild form, which usually occurs in older animals, is characterized by transient fever and loss of appetite with recovery. Infected sows may show no ov ert clinical signs but continuously shed virus to their young and to other swine they contact.

15Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Sources of virus and transmission

Blood and all tissues, secretions, and excretions of sick and dead animals are sources of

virus [ 18 ] . CSF virus has been recovered from muscle and lymph nodes of infected pigs, and high titers of CSF virus have been isolated from bone marrow [ 22 ] . The virus may also be present in semen [ 19 ]

.

Transmission is generally directly from pig to pig, but products including fresh, frozen, or cured pork can infect other pigs via the oral route [ 23 ] . Imported pig products are freque ntly implicated in the introduction of CSF virus into previously free regions, primarily through the practice of swill feeding [ 24 ] . Dahle and Liess (1992) demonstrated

that the oral infectious dos e of CSF virus is very low [ 25 ] . Indirect transmission may occur via movement of people, wild animals, and inanimate objects such as live

- haul

trucks [ 26 ]

.

In countries that are free of CSF in domestic swine, epidemics in wild boar are often started by feeding of infected human food waste. Abnormal mortality and sometimes obviously sick ani mals are the first indicators of CSF introduction into a wild boar population [ 27 ]

.

Inactivation and survival

The CSF virus is quite hardy, being stable between pH 4 and 10 [ 28 ] and also stable at low temperatures [ 29 ] . The virus can survive for long periods in cool, moist, and protein

rich environments such as stored meat: survival times of more than 4 years in frozen pork and at least 85 days in fres h, chilled pork have been reported [ 23 ] . CSF virus would likely remain viable in fresh meat even after carcass maturation and is unlikely to be destroyed by transport or cold storage. Survival times in cured or smoked meat ranging from 17 days to more than a year have been reported.

The CSF virus is readily inactivated by detergents, lipid solvents, proteases, and common disinfectants, as well as pasteurization and cooking, although sensitivity to heat can vary among strains. The virus can be inactivated by a variety of time/temperatures combinations as well as curing and drying through various processes [ 30 ] . CSF virus is moderately fragile in the environment, but can remain infe ctious for months in refrigerated meat and years in frozen meat [ 15 ]

.

Vaccination

Vaccines against CSF virus are available in some areas. Vaccination can protect animals from clinical disease but does not prevent infection. Currently available live attenuated vaccines are effective in limiting clinical disease but allow the CSF virus to circulate subclinically. Vaccination is therefore considered inappropriate in regions where a stamping out policy exists and where the entire swine population is susceptible due to the standard practice of non

- vaccination [ 31 ] . In areas where CSF is endemic, well

16Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

administered vaccination programs can ev entually eliminate the infection from herds
[ 15 ]

.

Laboratory Diagnosis

Laboratory confirmation of infection, essential during an outbreak situation, is complicated by the close antigenic relationship of the CSF virus with bovine viral diarrhea virus and border disease virus (also pestiviruses) [ 13 ] . Identification of the virus, its nucleic acid, or associated antibodies confirms the diagnosis. The OIE recommends detection of CSF antigen via direct fluorescent antibody test on cryostat sections of organs fro m infected pigs [ 32 ] . A panel of monoclonal antibodies is then used to differentiate from other Pestivirus antig ens. Virus isolation techniques and polymerase chain reaction may also be used. Antigen

- capture enzyme

- linked immunosorbent assays (ELISAs) are useful for herd screening, but should not be used on a single animal basis.

Detection of virus

- specific antibodi es is particularly useful in herds suspected of being infected at least 21 days previously with CSF virus [ 32 ] . S erological methods are essential if a country wishes to be internationally recognized as being free from the disease in the absence of vaccination. Screening tests must be followed by confirmatory tests that are specific to the CSF virus. Certain ELISAs ar e relatively CSF specific, but the definitive method for differentiation is the comparative neutralization test, which compares the level of antibodies to different Pestivirus species.

17Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________



## Section 4. Release Assessment

A r elease assessment describes the bi ological pathway(s) necessary for an importation activity to introduce pathogenic agents into a particular environment and estimates the probability of that introduction [ 2 ]

. This release assessment addresses the factors

described under 9 CFR 92.2 for evaluation of the animal health status of a region [ 33 ]

. Risk factors and issues of concern, which may directly or indirectly affect the risk estimate, are identified during this process. APHIS evaluated the cu rrent status of

Mexico w ith regard to CSF to decide whether it can allow the importation of fresh pork and pork products originating from additional Mexican States and under what conditions

.

4.1. Scope of the evaluation

APHIS considers all of the territory of Mexico

, except the nine states that APHIS currently considers as CSF

- free , in this evaluation of the classical swine fever (CSF) risk for importation of pork and pork products originating in and exported from this region of Mexico ( see Figure 1 , page 11 ).

4. 2

. Veterinary control and oversight

Organization of the Official Veterinary Services [ 36

- 60 ]

Central veterinary a uthority

The Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentación ( SAGARPA

, Ministry of Agriculture, Livestock Production, Rural Development, Fishery, and Food) is the F ederal department with in the government of Mexico responsible for the agriculture and livestock sectors. SAGARPA is considered equivalent

to U nited S tate s D epartment of A griculture (USDA)

.

Within SAGARPA , there is Servicio Nacional de Sanidad, Inocuidad y Calidad Agroalimentaria (SENASICA, the National Service of Agrifood Health, Safety and Quality). SENASICA, equivalent of USDA’s Animal and Plant Heal th Inspection Service (APHIS), is divided in to several general divisions; three of them are directly

focused on animal health issues ( see Appendix 2 : SENASICA Organization Chart)

. These divisions are Direccion General de Salud Animal (DGSA, General Direct orate of Animal Health); Direccion General de Inspeccion Fitozoosanitaria (DGIF, Animal and Plant Health Inspection Service General Direction); and Direccion General de Inocuidad y Calidad Agroalimentaria (DGICA, General Directorate of Agrifood Safety and Quality Control). The role of these divisions in CSF control in Mexico is discussed below.

The DGSA , headed by the Chief Veterinary Officer of Mexico, is comprised of four

animal health divisions and is supported by three additional entities.

18Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

The Dirección de Importación, Exportación, Servicios y Certificación Pecuaria ( Directorate of Import, Export, Services, Animal and Anima l Products Certification) is responsible for issuing import and export permits for animal s and animal products ; registration and regulation of the manufacture of veterinary product s (chemical, pharmaceutical, biological and feed products); approval of animal disease diagnostic and product quality control laboratories; accreditation of veterinarians in certain disciplines (labor atory diagnostic s , ruminants, poultry, swi ne, animal and animal product movement, slaughterhouses, and the manufacture of pharmaceutical, biological

, and/or food products ); and issuing health certificates necessary for movement of animals and/or animal pro ducts within Mexico.

The Dirección de Campañas Zoosanitarias ( Directorate of Animal Health Programs ) is responsible for animal health programs conducted in Mexico to control and eradic ate
animal diseases . This division was responsible for conducting Mexico’s National Classical Swine Fever Campaign which is described later in this document

.

The Dirección de Vigilancia Epidemiológica ( Directorate of Epidemiological

Surveillance ) is responsible for analyzing surveillance data and developing risk analyse s in support of domestic and foreign regionalization decisions.

The Dirección de Sanidad Acuícola y Pesquera ( Directorate of Animal Health Aquaculture and Fisheries) is responsible for aquaculture and fisheries health programs

conducted in Mexico to cont rol and eradicate diseases and plagues affecting live aquatic species. This Direction was incorporated to the structure of the Animal Health Direction

in 2007.

The animal health activities of DGSA are supported by the Comision Mexico

- Estados Unidos para l a prevencion y control de la fiebre aftosa y otras enfermedades exoticas ( CPA

, Mexico

- United States Commission for the Prevention of Foot and Mouth Disease

and other Animal Foreign Diseases ), located in Mexico City. CPA is in charge of the prevention, surveillance, diagnosis, control and eradication of exotic and emerg ing animal diseases and pests. Its structure is within SENASICA and is part of DGSA. C PA operates a foreign animal disease diagnostic laboratory network

.

Since the January 2009 self

- d eclaration by the Government of Mexico that its entire territory is free of CSF, the CPA laboratory has assumed the responsibility for all CSF diagnostic testing. The national territory has been divided in to eight regions, commanded by 8 Regional Coordinat ors and 69 Zone Coordinators that respond to the notifications of suspicious exotic and emerging animal disease and pest cases. CPA is also involved with

a continuous training program, performed through courses, seminars and dri lls, aimed to SAGARPA person nel and personnel from State Committee s for Animal Production Promotion/Protection, and other professionals from different institutions, such as the Secretary of Environment and Natural Resources, Secretary of National Defense, or the Secretary of Public E ducation. This allows the personnel specialization and selection for, afterwards, being part of the respective organization chart of the State Groups for Animal Health Emergency or GEESA by its Spanish abbreviation in initials.

19Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Centro Nacional de Servicios de Diagnostico en Salud Animal (CENASA ), Mexico’s national veterinary services diagnostic laboratory , is centrally located in Tecamac, State

of Mexico

. This laboratory receives submission s for the diagnosis of endemic animal diseases; verifies the quality control of biological products submitted to SAGARPA for

their offi cial registration; and accredits other laboratories in Mexico for animal disease proficiency and quality control.

A second national laboratory, Centro Nacional de Servicios de Con statacion en Salud

Animal (CENAPA), located in Jiutepec, State of Morelos

, is the toxicology laboratory responsible for toxic and pesticide residue analy s es of food of animal origin. This laboratory also verifies the quality control of tick pesticides subm itted to SAGARPA for their official registration.

DGIF , the second of three SENASICA divisions involved in animal health activities, is responsible for the Sistema Nacional de Cuarentena Agropecuaria (National System of Animal and Agricultural Quarantine), a system of Federal inspection check points providing internal and external movement controls for animal and animal products. The External Quarantine Service provides sanitary control activities at ports, airports and borders to prevent introduction of animal diseases into Mexico via animal and animal product importation. The Internal Quarantine Service manages all activities relevant to preventing the spread of diseases already existing within the entire national territory,

from affected areas into free areas. There are 4 5 permanent federally maintained inspection posts on major highways distributed along five corridors in Mexico, t he northern, central, southern, isthmus and peninsular quarantine lines . These effectively divide Mexico into six regions. The federal inspections posts provide general animal

health movement controls , including swine movement controls for pseudorabies. After

Mexico’s self

- declaration of CSF

- freedom in January 2009, there are no specific CSF

movement restrictions

. In addition to F ederal inspection posts

, there are S tate

- operated inspection posts throughout the country which perform varying animal

- health

- related

duties

. The role of the inspection posts are described later in this document.

DGICA

, the third division of SENASICA with animal health responsibilities, has authority over federally approved slaughterhouses and meat processing and handling facilities, known as Federal Inspection Type Establishments (TIF). 2 DGICA is equivalent to USDA ’s Food Safety and Inspection Service (FSIS ). To ensure compliance, TIF establishments have permanent (i.e. stationary) F ederal personnel with oversight over the animal health processes and products. These establishments comply with international sanitary requirements

, have official veterinary officers and are certified by the countries to which they export. TIF supervisors

, assigned to an area or State

,

2 Federal Inspection Type Establishments (TIF) are slaughterhouses and meat processing and handling facilities approved by DGICA, an agency equivalent to USDA, Food Safety and Inspection Service (FSIS). TIF establishments have permanent sanitary inspection of their processes and products through offic ial veterinarians to monitor compliance with SAGARPA regulations. These establishments comply with international sanitary requirements and have official veterinary officers and are certified by countries to which they export. Pork or pork products must b e processed through FSIS

- approved TIF establishments for export from Mexico to the United States.

20Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

verify the activities of the official v eterinarians in charge at the TIF e stablishments. In addition, throughout the country there are State

- inspected municipal plants slaughtering swine and processing pork for local markets and personal consumption under the supervision and control of the Department of Health

.

In each S ta te there is a F ederal SAGARPA delegate in charge of all Federal personnel responsible for animal health activities. Among other duties, these official veterinarians are responsible for ensuring compliance with Mexican Official Standards (NOMs) regarding animal health cont rol and surveillance programs, including local prevention and control measures, reporting livestock census information, emergency response
, sampling, premises identification, movement controls and record

- keepin g.

State veterinary authority [ 36

- 60 ]

The animal health infrastructure at the State level exists as collaboration between the SAGARPA Delegation in the State (SAGARPA State Delegation), the State Government, and a State animal health committee comprised of industry and producer representatives

, Comité de Fomento y Proteccion Pecuaria

, or CEFPP [ see Figure 2 ] . In addition there

are various organizations and associations representing the interests of livestock producers. In total, t here are 33 State CEFPPs in the country, where 1,415 veterinarians

work.

Figure 2

.

Source: SAGARP A [ 36

- 60 ]

In Mexico, much of the field work for SAGARPA’s animal health activities is provided through the State CFPP which receives funding from the State government, the livest ock **STRUCTURE OF STATE VETERINARIA N SERVICES** 

STATE BRANCH

OFFICES IN

SAGARPA

SECRETARIES OF
AGRICULTURE AND
ANIMAL PRODUCTION

DEVELOPMENT

STATE COMMITTEE OF
ANIMAL PRODUCTION

DEVELOPMENT AND
PROTECTION HEAD OF THE
PROGRAM OF ANIMAL

HEALTH AND

SUPPORTING STAFF HEAD OF
CADER HEAD OF

DDR

SUPPORTING
STAFF

S.C.

BOVINES S.C.

BIRDS S.C. PIGS S.C. BEES S.C.

MOV. S.C.

EPIDEM.

21Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

industries in the State, and the SAGARPA State Delegation. Each of these parties contributes a third of the budget required for supporting the yearly sanitary activities. The annual budget and program of activities of the CFPP is approved by SAGARPA.

As part of the National CSF Emergency Plan which is discussed later in this document

, are the Grupos Estatales de Emergencia en Salud Animal (State Animal Health Emergency Groups, GEESAs). GEESAs are composed of animal health personnel from

the Federa l and State governments, CFPP, industry, swine producers, and private veterinarians. These individuals receive training in foreign animal diseases and participate in simulation exercises and respond to emergency situations at the State and/or

Federal leve l.

Legal Authority for Animal Health Activities [ 34

- 60 ]

The Federal Law of Animal Health is the legal basis applied in all the Mexican Republic and is the equivalent of USDA, APHIS’ An imal Health Act. Article IV of this Law, gives SAGARPA the authority to promote, encourage, organize, supervise, coordinate and execute, all types of activities pertaining to animal health in which different organizations and agencies of the municipal, S tate and F ederal governments can participate as well as individual stakeholders

.

The Mexican Official Standards or NOMs ( Normas Oficiales ) are the F ederal laws regulating these activities. From 1995 until January 2009, Mexico conducted a CSF eradication campaign under regulations aut horized by NOM

- 037

- ZOO

- 1995 and is

described later in this document

.

Although NOM

- 037

- ZOO

- 1995 remains in effect after Mexico declared their entire territory to be CSF

- free , the NOM provides continued authority to conduct CSF surveillance activity

, prohibition of CSF vaccination and emergency response for in cases of CSF suspicion [ 34 ] . Eventually Mexico will replace this NOM with a different type of regulatory instrument

. According to SENASICA, the new regulatory instrument will be

called the “Agre ement in w hich are disclosed the a nimal h ealth m easures a pplicable for

c lassical s wine f ever for the e pidemiological s urveillance in the Mexican United States Territory

. ” This Agreement will provide the authority to establish the epidemiological

surveilla nce and investigation activities to monitor for any reintroduction of CSF into Mexico, including the regulation of trade, and the emergency response authority if reintroduction occurs. The Agreement will also provide case definition and diagnostic

paramet ers for CSF, prohibit the use of CSF vaccine in the country (except if an animal health emergency is declared), and describe the process by which Mexico will recognize the CSF status of exporting countries.

Other NOMs which impact the control of CSF in Me xico are:

• NOM

- 046

- ZOO

- 1996, National Epidemiological Surveillance System.

• NOM

- 018

- ZOO

- 1995, Verification by Approved Veterinarians.

• NOM

- 003

- ZOO

- 1994, Animal Disease Diagnostic Laboratory Criteria.

• NOM

- 036

- ZOO

- 1996, Minimum Requirements for CSF Vaccines.

22Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

• NOM

- 054

- ZOO

- 1996, Quarantine Procedures for Animal and Animal Products.

Discussion

APHIS concludes that Mexico has the necessary veterinary infrastructure to conduct CSF

control activities. One of the strengths observed by the APHIS site

- visit team was t he

apparent cooperation existing within the different components of the State veterinary infrastructure, including the State SAGARPA Delegation, State Government, State Animal Health Committee and producer and industry organizations. However as an excepti on to this strength

, the APHIS team observed weakness es in the communication and cooperation between States and between State and Federal entities in regards to epidemiological investigations that involved more than one State. During the period of

the APH IS evaluation, Mexico has improved inter

- agency communication ; however, as

discussed later in this document, APHIS recommends continued improvement to involve the laboratory diagnosticians in communications regarding epidemiological investigations ( see section 4.9. Disease surveillance in the region ).

4.3. Disease history and vaccination practices [ 36

- 6 0 ]

Disease s tatus in the region

In January 2009, the Government of Mexico declared that the entire country was free of

CSF in accordance with the National CSF Campai gn, as described in the Official

Mexican Standard NOM

- 037

- ZOO

- 1995 which is discussed later in this document [ 34 ]

. This declaration was the culmination of the National Campaign which officially began in

Mexico in 1980. The last CSF outbreak in domestic swine in Mexico reported to the OIE

occurred in Guer rer o in 2009 [ 41, 42, 65 ]

. 3 The last reported cases in each State under

review are summarized in Table 1

.

3 In December 2009, SENASICA reported to the OIE the occurrence of 2 CSF outbreaks in the State of Guerrero during March 2009 [41, 65]

. The source of the outbreaks was not determined. This report remains the official statement to OIE by SENASICA regarding these outbreaks and the OIE continues to recognize that the last CSF outbreak in Mexico occurred in 2009 . However during the November 20 12 site visit, SENASICA advised the APHIS team of a contradictory conclusion reached during a retrospective study recently conducted by SENASICA. SENASICA presented documentation to APHIS asserting that the 2009 diagnostic tests confirming CSF virus were i nvalid; however, the information provided to APHIS

was inconclusive and therefore insufficient for APHIS to discount the 2009 OIE report [41, 42, 65]

.

23Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Table 1 : Significant Dates for the CSF Campaign in Mexico

State Last

Outbreak

Year Last

Vaccination

Year Eradication

Phase

Year Date Free phase

Declared Aguascalientes 1999 2002 2004 July 18, 2006 Chiapas 2002 2006 2006 January 30, 2009

Coahuila 1984 1993 1993 July 24, 1995

Colima 1999 2004 2004 July 18, 2006

District Federal 1999 2006 2006 June 9, 2008 Durango 1998 1994 1994 October 7, 1999 Guanajuato 2003 2004 2004 July 18, 2006

Guerrero 2009 2005 2005 August 1, 2007 Hidalgo 2003 2005 2005 March 12, 2007

Jalisco 2001 2004 2004 July 18, 2006

Mexico 2005 2006 2006 June 9, 2008

Michoacán 1999 2004 2004 July 18, 2006

Morelos 1998 2006 2006 June 9, 2008

Nuevo Leon 1990 1993 1993 July 24, 1995

Oaxaca 1998 2005 2005 January 30, 2009

Puebla 1998 2005 2005 December 6, 2006
Querétaro 2000 2000 2004 July 18, 2006

San Luis Potosí 1999 1998 2003 July 18, 2006

Tabasco 2000 2005 2005 January 30, 2009 Tamaulipas 1999 1993 1993 July 24, 1995

Tlaxcala 2005 2004 2005 March 12, 2007

Veracruz 1998 2005 2005 December 6, 2006

Zacatecas 1991 2004 2004 July 18, 2006

Source: SAGARPA [ 39, 41 ]

Mexican officials claim that feral swine or free

- roaming wild pig population s are not
known to exist in Mexico . However, there are several commercial farms raising herds of

wild collar ed peccaries and European wild boars for sporting purposes. These farms are

located in areas distant fro m domestic commercial swine production facilities

. These

herds are also monitored as part of the national CSF surveillance activities

. Exposure to

CSF virus ha s not been detected in these herds. APHIS does not consider it likely that

feral swine or wild boar are a risk for introduction or spread of CSF virus in Mexico

.

As previously mentioned in the introduction ( see Section 2), SENASICA had reported a pattern of serological detection of antibodies to CSF prior to the 2008 site visit by

APHIS. During that site visit APHIS identified deficiencies in the laboratory diagnostic protocols and epidemiological investigation of suspect cases that cast doubt on interpretation of the laboratory results and investigation reports. APHIS provided

technical assist ance to and worked with SENASICA to resolve these problems and subsequently in September 2011determined that Mexico’s foreign animal disease laboratory network (discussed in more detail later in this document) were operating in

accordance with internationa l standards.

However, SENASICA continued to report serological findings of CSF antibody

detection

, collected during both active and passive surveillance activity, although at less

24Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

frequency than in 2008. APHIS audited the epidemiological and laboratory records for

these suspect cases for each state under evaluation. Most states had several suspect cases that occurred after September 2011. In addition

, APHIS sent a team of foreign animal disease diagnosticians (FADDs) to assist with the collection of samples for suspect case investigations in the State of Guanajuato ( see Appendix 4 ). In cases where clinical signs of disease were present, the investigations often revealed one or mo re diseases that may

have been either co

- existing with or unrelated to infection with CSF virus. CSF virus could not be confirmed in any of these suspect case investigations; however, the cause(s) of the CSF antibody detection remained unexplained.

Durin g the two 2012 site visits, the APHIS team again audited suspect case investigation s and laboratory records. In most cases, the records indicated that the investigators followed proper procedures to close the investigations by excluding CSF as the most

li kely cause of antibody detection. However

, in 10 States (Chiapas, Colima, Guanajuato, Guerrero, Hidalgo, Jalisco, Mexico, Michoacán, Morelos and Tabasco ) there was at least

one suspect case for each state in which CSF virus exposure could not be ruled out because the investigations were incomplete

. In many of these cases

, investigators either

did not sample the appropriate animals with the appropriate diagnostic test or the animals were improperly identified or destroyed before the proper sampling and test ing could be

conducted. In other case investigations, APHIS is concerned about the thoroughness or

lack of trace

- in and trace

- out activities. SENASICA with technical assistance from APHIS has made significant improvement in implementing field investigation protocols that meet internationally recognized standards. However, additional work needs to be done to raise the level of performance in all states, especially Chiapas.

It is important to note that CSF virus was never confirmed or isolated in any of these

suspect cases and in most of these cases cl inical signs of disease were absent

. It is also important to note that sero

- conversion within the herd and surrounding herds was not

observed. In a few instances where clinical signs of disease were present, the investigators were able t o confirm other infections but such findings neither increase nor decrease suspicion of CSF exposure as a co

- existing factor.

In the case of Chiapas, the APHIS team noted that a cluster of 7 suspect cases were detected in 2012 near the border with Guatemala which at the time was experiencing a CSF epidemic. This cluster was characterized by extremely high serum neutralization titers (in excess of 1:2,5 6 0) specific to CSF virus , ruling out exposure to other

pest iviruses . The case investigations could not determine the cause of these high titers

but CSF virus was never confirmed or isolated

.

Discussion

Serologic evidence of exposure to CSF virus has been found in a number of Mexican States. The specificity of t he antibodies was demonstrated by comparative neutralization tests; however, no virus has been detected. I t has not been possible from the data

available to determine whether these antibodies were produced after infection with a field

strain of CSF virus o r after vaccination with CSF vaccine. At this time there is no

25Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

diagnostic test that can distinguish between exposures to the field virus versus exposure s to the PAV

- 250 CSF vaccine last used in Mexico and currently in use in Central

America. These findings increase the level of uncertainty regarding the presence or

absence of CSF virus in Mexico

.

APHIS considers three possible explanations for the high SN titers found in the sera of pigs during several active and passive surveillance invest igations. From most likely to least likely, these three explanations are:

1) Exposure to CSF vaccine virus: possible explanations include illegal use of

vaccine (smuggled into Mexico or diverted from vaccine produced in Mexico for export) or residual titers from legal vaccination prior to 2006 (smuggled vaccinated pigs is a possibility however not likely due to the strength of border inspection activities) . However it is important to note that legal vaccination ceased more than 6 years ago in Mexico and mos t seroposit ive swine found in

Mexico were animals from 3 to 5 years of age although some were less than two

. 2) Exposure to field strain CSF virus: high SN titers in several pigs in multiple states and clustering of cases near the border with Guatemala suppo rt this explanation. However, in all suspect case investigations that APHIS reviewed and consider to be complete, antigen tests have not revealed live CSF virus and tests from perifocal sampling have not documented spread of infective CSF virus. 3) False po sitive test results: no diagnostic test has perfect specificity, although this explanation is thought to be least likely because of the combined specificity of the series of CSF serological tests ( ELISA, immunoperoxidase (IP) and serum neutralization (SN) ) approaches 100%. Both reference and regional laboratories exhibited excellent performance on CSF diagnostic tests, record keeping, and quality assurance

.

Since t he pattern of CSF antibody detection in several areas of Mexico is un explain ed from the evidence presented , then the level of uncertainty, regarding the presence or absence of CSF virus in the country, i s increased . It is possible that such a pattern could be indicative of a country in the last stages of eradication of CSF , perhaps a country that has recently eradicated CSF but has residual CSF antibodies and/or sporadic illegal CSF

vaccination or smuggled CSF infected or vaccinated swine perhaps from neighboring countries where the virus is known to be present.

An additional con cern is c ontinued problems with the quality of some field epidemiological investigations of CSF suspect cases . This problem raise s the concern

about the potential for delay or failure to investigate all possible epidemiological links

, potentially resultin g in further spread of the virus

. However APHIS acknowledges the ongoing efforts of SENASICA to address this issue, as evidenced by its recent efforts to correct deficiencies with the investigations conducted in Chiapas. APHIS also acknowledges the ongoi ng enhanced surveillance activities conducted by SENASICA in Chiapas and other states bordering Guatemala.

26Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

The uncertainty surrounding the serological findings leads APHIS to conclude that the most likely explanation for all of Mexico except Chiapas is related to residual vaccine titers and illegal use of vaccine. However, the pattern of findings in Chiapas along with its close proximity to known CSF viral activity in Guatemala prevents APH IS from concluding that antibody detection in Chiapas is due solely to exposure to vaccine virus.

D isease control program

Since January 2009 Mexico considers that CSF had been eradicated from the country ; therefore it currently does not conduct an active disease control program although it

continue s to conduct CSF surveillance under the authority of the National CSF Campaign regulation (NOM

- 037

- ZOO

- 1995)

. The National CSF Campaign regulation provides authority for CSF surveillance , movement control , and emergency re sponse activities

. The Government of Mexico considers that as of January 2009 all Mexican States

achieved disease freedom status in accordance with the provisions of the National CSF Campaign

. A description of the National CSF Campaign is helpful to understand the process utilized by Mexico in pursuit of eradication of CSF.

National Classical Swine Fever Campaign

Because of the economic importance of swine production to the country, the Mexican

government pursued eradicat ion of the CSF virus from the country . The Official

Mexican Standard NOM

– 037

– ZOO

– 1995 , National Classical Swine Fever Campaign, proposed on October 11, 1995 and finalized on August 26, 1996, describes the CSF disease control program [ 34 ]

.

The campa ign was basically directed towards domestic swine production

, but its

measures could have been applicable to feral swine if deemed appropriate by the Mexican government. Responsibility for the campaign was shared by SAGARPA, S tate governments, livestock p rotection and promotion committees, producer associations, owners, dealers, transporters, and other individuals and entities involved in swine production.

The campaig n called for the recognition of S tates or regions within S tates to be classified

as bei ng in one of three phases: CSF

- free, e radication, or c ontrol. At the time of the

initial site visit

, May 2008, Mexico classifie d 6 S tates as being in the eradication phase

, and 26 S tates, including the eight in the Central Western Region , as being CSF

- free ( see Figure 3 , page 2 7 )

. The eradication

- phase States were in central (Mexico City area) and

southern Mexico

. Inspection posts , discussed later in this document

, were placed to protect the status of the lower risk region s from the eradication and control phase regions.

In control phase areas, CSF vaccination was allowed and intensive vaccination programs were directed at high

- risk and high swine population zones. In accordance with the NOM, vaccine production, handling , and use were subject to authorization by SAGARPA. Each farm was required to keep a record of vaccinations and vaccination certificates were issued by official or approved veterinarians. Monitoring and sentinel

27Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

programs were implemented by SAGARPA as pa rt of the ongoing epidemiological surveillance. The last control phase States or regions were in the central Mexico City area and in southern Mexico (see Figure 4 ).

Figure 3

. Epidemiological Status National CSF Campaign, 2005

Source: SAGARPA [ 39 ]

Figure 4

. Epidemiological Status National CSF Campaign, 2008

Source: SAGARPA [ 39 ] Libre (27)

*Erradicaci ó n (6)

Control (0) Situaci ó n de la fiebre porcina cl á sica

En M é xico, 2008*

***Hasta febrero de 2008** SAGARPA

*Los 6 estados en

erradicaci ó n est á n actualmente en

revisi ó n para pasar a fase libre en FPC

28Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

A S tate or region could move into the eradic ation phase of the program once vaccine marketing and use were stopped and at least 12 months elapsed since the last CSF

outbreak. In the eradication phase, t he S tate or region was required to control animal movement along the main routes of entry, conduct epidemiological surveillance, implement a sentinel program, devel o p a n animal health emergency p lan , and fund an emergency insurance or indemnity program. Six months after a State or region moved from control to eradication phase, a sampling progr am was to be carried out by Federal

and S tate officials, in cooperation with producer groups.

After a S tate or region had been in eradication phase for at least 12 months and there ha d

not been a case of CSF in at least the previous 24 months, it could seek recognition as

CSF

- free. A S tate or region would be declared CSF

- free by a resolution of the Secretary of Agriculture and Rural Development published in the Federal Gazette

. Free S tates were then required to continue to verify their status by condu cting serological sampling surveys every six or twelve months as scheduled by SAGARPA in cooperation with State

officials.

The NOM prohibit ed the feeding of swill or garbage to swine throughout Mexico, regardless of phase in which the S tate or region was classified. As the Central Western Region prepared to seek CSF

- free recognition, an education program was conducted and a questionnaire given to all backyard and commercial swine operations. This questionnaire specifically asked about feeding practices to reinforce the prohibition of swill or garbage feeding.

The protection of the status of CSF

- free States and the status of S tates under eradication

relied on strict control of movement of swine or pork products. State governments, in

addition to the F ederal government, operate d animal health checkpoints within and

between State s. The NOM basically provided that swine move only between areas of equal CSF risk or from higher to lower CSF risk areas. Swine from control State s or regions were prohibited from moving into free or eradication areas . Swine from eradication phase areas were also prohibited from moving into free areas. Movement of pork and pork products were similarly regulated, except an allowance was made to move

heat

- treated products from origins of higher risk to destinations of lower risk.

In the event of suspicion of CSF, SAGARPA was to have be en notified and a precautionary quarantine established surrounding the affected premise pending laboratory

confirmation. In control zones, sick animals were depopulated and other swine in the surrounding areas were vaccinated. In free and eradication S tates or regions, if CSF was confirmed the S tate or region was temporarily downgraded to control phase status and the

affect ed and exposed premises were depopulated . If it had not been feasible to depopulate, the region would have reverted to control zone status and would then have

follow ed the procedures established in the NOM to achieve free

- zone recognition as the

situation improves

. Otherwise, a ffected premises were cleaned, disinfected and repopulated in accordance with standards outlined in the NOM. If there were no further evidence or suspicion of CSF during the six months following repopulation, then the free

or eradi cation status of the area would be restored.

29Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________________________________________________

Discussion

S ince January 2009, Mexico considers all of its country to be CSF

- free and accordingly does not impose restrictions on the movement of swine, pork and pork products within the country on the basis of CSF. 4 Therefore these commodities may move freely throughout Mexico’ s domestic markets.

C urrently APHIS regionalizes Mexico for CSF by recognizing 9 States as being CSF- free and considers the remainder of the country to be affected. At the time that APHIS recognized these 9 States, Mexico regionalized its territory in accordance with provisions of the National CSF Campaign which at that time effectively provided separation of the regions of Mexico considered by APHIS to be CSF- free fr om the regions APHIS

considered to be CSF- affected.

Through provisions in the Code of Federal Regulations (CFR), Title 9, Section 94.32

, APHIS impos ed r estrictions for por k f or export from Mexico to the U nited S tates tha t

r equire Mexico to c ertify that por k is de rived from s wine t hat m eet t hree conditions.

Those conditions a re: 1. S wine originate from regions recognized by APHIS as being CSF- free 2. Swine have not transited regions considered by APHIS to be CSF- affected

unless moved under seal 3. Swine have not commingled with swine that have been in regions considered by

APHIS to be CSF

- affected

V

accination status of the region [ 36-60 ]

V accination for CSF is prohibited in Mexico and CSF vaccines are not legally available.

T he veterinary infrastructure of the CFPP al lows for frequent monitoring of the local feed stores where animal health biologica l agents and vaccines are marketed. It is not likely that the illegal sale of CSF vaccines would go undetected. If illegal vaccination occurs as APHIS suspects, then the v accine is likely diverted from Mexico’s vaccine export market or smuggled into Mexico. In either case vaccine would likely be distributed through illegal and unregulated market channels.

H owever, illegal vaccination and the illegal import of vaccinated swine are likely explanations for exposure of Mexican swine to CSF antigen detected through Mexico’s CSF surveillance program (see discussion in section on Disease Status ).

Discussion

S ince neither vaccination nor CSF virus have been confirmed in suspect cases where CSF antibodies were detected, then the presence of CSF virus and illegal vaccination cannot be excluded. Currently there is no validated diagnostic method that can distinguish

4 Mexico enforces movement restrictions as a component of its pseudorabies eradication program.

30Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

whether the detected CSF antibodies were from exposure to vaccine or a field strain of

CSF virus. Because of this uncertainty explaining the source of CSF antigen exposure,

APHIS must consider there to be an increased likelihood for release of CSF vi rus associated with this factor.

4. 4

. Livestock demographics [ 36

- 60 ]

Mexico is an importan t producer of pork, currently ranked fifteen in world pork production and second in Central and South America after Brazil. Commercial farms are responsible for half of swine raised in Mexico, another 20% are produced on medium

sized (10 to 40 hogs) facilities , and 30% are raised in backyard farms (averaging 5 hogs). Seventy percent of pork produced is marketed fresh and the remaining 30% is processed.

Jalisco is the larg est pork producing State in Mexico; and the Jalisco, Guanajuato and

Michoacán area in the Central Western Region is the highest concentrated swine production region in Mexico. The remainder of the CWR has limited commercial swine production. Two o ther States , Puebla and Veracruz, are important commercial swine production areas of Mexico. Table 2 lists the swine population by State

.

Table 2 . Swine Production by State

, 2011

State Commercial population Swine production units Backyard

p opulation Backyard

u nits Aguascalientes 64,412 30 15,878 4,396 Chiapas 66,253 50 271,051 72,020

Coahuila 16,638 6 16,919 1,820

Colima 43,178 51 2,144 450

District Federal 0 0 16,427 1,000 Durango 23,070 3 22,709 7,201 Guanajuato 759,061 776 135,057 20,269

Guerrero 35,360 30 586,178 145,036 Hidalgo 57,163 64 204,757 77,566

Jalisco 2,715,841 1,177 28,586 972

Mexico 78,391 33 45,143 8,533

Michoacán 312,252 354 299,587 24,972

Morelos 111,541 22 28,544 2,994

Nuevo Leon 301,273 45 6,715 1,303

Oaxaca 44,597 38 665,733 188,512

Puebla 511,896 74 352,351 78,266 Querétaro 176,401 54 58,300 7,287

San Luís Potosí 38,289 13 113,063 30,915

Tabasco 396 1 274,658 248,348 Tamaulipas 79,431 16 96,400 23,656

Tlaxcala 21,756 29 65,020 28,286

Veracruz 969,183 125 74,257 9,282

Zacatecas 28,302 9 235,030 46,725

Source: SAGARPA [ 36

- 60 ]

31Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Central Western Region

Jalisco has the largest commercial swine industry on all the States in the Central Western Region. Nearly two

- thirds of all commercial swine production in the region is raised in Jalisco; over half of all swine reared in the region if backyard herds are i ncluded. Over 40% of commercial swine raised in the State are shipped to slaughter and sale in the Mexico City area ( see Figure 5, page 3 2 ) . Another 30% are commercially marketed within Jalisco which includes the densely populated city of Guadalajara. T he remaining

30% are marketed in other areas of Mexico. At the time of the site visit, there were 6 TIF slaughterhouses in Jalisco which produ ce products eligible for export and an additional

10 8 municipal slaughterhouses serving the needs of local consum ers. Jalisco seeks to develop export markets to Japan and other Asian countries. Jalisco has several major truck routes that are used to transit swine and pork shipped from Sonora, Sinaloa and other states to the north to the Mexico City area.

Guanaju ato has the second largest swine population in the Central Western Region. Most hog production is concentrated in the southwestern part of the state adjoining the dense swine production areas in Jalisco and Michoacán. A large volume (nearly 1.7 million hogs) transit Guanajuato heading to be slaughtered and processed in Mexico City. A

swine semen collection center is located in an isolated area of the state removed from the dense swine production area. This center serves the needs of local swine produce rs. In Guanajuato, there were 34 municipal slaughterhouses and 4 TIF plants. Several major trucking routes cross the State so there is also a high volume of hogs transiting the State in route to or from Mexico City.

Michoacán is the third largest swine producing state in the Central Western Region. Its commercial swine production area is located in the northern part of the State adjoining the dense swine production areas in Jalisco and Guanajuato. The southeastern area of the State, bordering the State s of Mexico and Guerrero, has a low

- density swine population comprised primarily of backyard swine. Approximately 30% of swine reared in

Michoacán are for local consumption. The remaining 70% are sent out

- of

- state to consumers in the Mexico City area. B ecause three major interstate trucking routes cross the state, a large volume of live hogs and pork transit Michoacán. At the time of the site

visit there were two swine semen collections centers and a third one under construction.

These centers serve th e needs of the local swine producers. There is one TIF plant that slaughters hogs and 90 municipal slaughterhouses.

Queretaro also has a large commercial swine population, fourth largest in the Central Western Region. Also, a sizeable population of back yard swine is reared in this state. In addition to local hogs raised for commercial markets, hogs are transported from other states, especially Sonora, to be slaughtered and processed. There is also one TIF plant in Queretaro that is authorized to slaugh ter and process hogs imported from the United States. Thirty

- nine percent of hogs raised in Queretaro are transported to slaughterhouses in the Mexico City area. Queretaro has one swine semen collection center which serves the needs of local producers ex clusively.

32Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Figure 5 : Swine movements into and out of Central Western Region, 2011

Source: SAGARPA [ 50 ]

33Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

The swine population in the remaining states of the region is fairly small with limited commercial production. Most swine are raised for personal consumption in non

comm ercial backyard operations. All the slaughterhouses in these states handling swine are municipal slaughterhouses, none are TIF type.

Other Mexican States

The States of Puebla and Veracruz have significant commercial swine production. Veracruz ranks second nationally in pork production and Puebla ranks fourth . Both are located east of the Mexico City population center. Veracruz has 2 TIF plants slaughtering swine and 13 municipal plants and Puebla has 1 TIF and 8 municipal plants. Swine move to and from these states to other states throughout Mexico.

The remaining States have relatively low commercial swine production though some have sizeable populations of backyard swine which are reared for local or self

consumption. Movemen t of local swine tends to be limited to local trips to municipal slaughterhouses or as sources of replacement stock. Many of these states receive swine for slaughter for the local market from the states with high commercial production. Also

some states e ncompass major routes of interstate traffic and therefore large volumes of

commercial swine transit the states.

During the November 2012 site visit, APHIS visited the State of Chiapas which is located

in southe ast Mexico and border s Guatemala t o the sou theast. Nearly all vehicular traffic between Mexico and Guatemala transits Chiapas and therefore was of particular interest to APHIS because of the ongoing CSF viral activity in central Guatemala. Private airplanes travelling from Central and South Ameri ca must first stop in Chiapas for inspection. Movement of swine and pork from Guatemala into Mexico is prohibited and SENASICA screens passengers and vehicles to intercept any unauthorized shipments of swine or pork into Mexico. However, the potential fo r illegal movement of swine or pork into Mexico from Guatemala is likely to occur through Chiapas. SENASICA has targeted Chiapas for enhanced CSF surveillance to increase the likelihood of early detection ( see section on surveillance).

Chiapas has only 50 commercial swine production units which are concentrated in the north and western areas of the state away from the border with Guatemala. However there is a sizable backyard swine population that is distributed throughout the state. Chiapas slaughters twice as many swine that are produced in other states than are produced and slaughtered within the state ( see Figure 6 , page 36 )

. There are two TIF plants located within the state and multiple municipal plants.

34Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Figure 6 : Swine movements into and out of C hiapas , 2011

Source: SAGARPA [ 58 ]

35Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Discussion

Mexico has developed an interlinked domestic swine and pork market. Movement of swine and pork generally flows towards the Mexico City area in the central part of the country. There swine are slaughtered and pork is then redistributed back throughout the country. There is also extensive movement of feeder stock and replacement sows

transit ing throughout the country, with a high volume of movement of live swine through

the CWR and central Mexico. Although these movements pose a potential means to quickly spread disease if the CSF virus were introduced, most of the interstate

movement s involve swine or pork derived from swine that were raised on commercial swine production facilities.

During the site visit s
, team members visited commercial swine farm s in Jalisco, Guanajuato, Puebla, and Chiapas

. The team observed good biosecurity measures and

record

- keeping at all of the commercial swine facilities . The team also visited non

commercial small and backyard herds in Colima, Guanajuato

, Jalisco, Mexico and Chiapas

. The owners or operators of these herds seemed to have some understand ing and awareness of the need for biosecurity and vigilance for reporting swine diseases. However, their knowledge was not complete and the team felt th at improvements could

be made

, and encouraged the local swine association representatives to not become complacent on the need for CSF awareness. This is especially important now that

Mexico has completed its National CSF Campaign

.

T here appeared to be good separation between commercial herds and backyard herds. This could serve as a key barrier to spr ead of CSF if reintroduced. This is especially important in the high density commercial swine production areas like the Central Western Region, as well as along routes where there is a high volume of swine movement. The

team’s observations were consisten t with the assessment of exposure risk that typically

occurs in CSF

- free countries, including the United States, where backyard herds are considered to have a higher likelihood of exposure to CSF virus if reintroduced than

commercial herds. So while the commercial herds are more protected through greater biosecurity measures, the potential exposure of backyard herds is more likely

. Therefore

,

as discussed in greater detail in the section on surveillance , targeted monitoring of backyard herds should be an essential strat egy adopted to quickly detect a re introduction

of CSF into a CSF

- free region. APHIS could not identify any other concerns related to

this factor that should be considered in the risk estimation.

4.5. Epidemiological separati on from potential sources of infection [ 36

- 60 ]

Disease status of adjacent regions

Mexico borders the United States in the north. The United States has been free of CSF

since 1976.

36Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Mexico shares its southern international border with Guatemala and Belize. APHIS currently considers both countries to be affected with CSF. Guatemala is currently experiencing an epidemic of CSF and Belize reported its last case of CSF in 1988 [ 65 ]

.

Currently, APHIS considers the States of Baja California, Baja California Sur, Campeche, Chihuahua, Nayarit, Quintana Roo, Sinaloa, Sonora, and Yucatan to be CSF

free. The remainder of Mexico is the subject of this evaluation

.

Discussion

The existence of common land borders with CSF

- affecte d regions in the south presents a
risk for re

- introducing CSF into Mexico ( see discussion in previous section) . However, Mexico prohibits the importation of swine, pork and pork products from countries it

considers to be CSF

- affected, including Belize and Guatemala.

Natural and manmade barriers

Mexico benefits from natural barriers to disease transmission from its location between the Gulf of Mexico on the east, the Caribbean Sea on the southeast and the Pacific Ocean

to the west. Mexico has two land bo rders, the northern border with the United States and

the southern border with Belize and Guatemala. The United States has been CSF

- free since 1978; therefore, Mexico’s northern border is not adjacent to a region of higher risk. So only the southern bord er of Mexico is considered to be adjacent to regions of higher

risk.

The Mexican State of Quintana Roo borders Belize to the south. Belize has not reported a CSF outbreak since 1988; however since APHIS has not conducted an evaluation of

their CSF stat us, APHIS considers Belize to be CSF

- affected [ 65 ]. APHIS has previously evaluated the CSF exclusion activities of Mexico along its border with Belize as part of its evaluation of the CSF

- status of Quintana Roo . In those reviews, APHIS did not identify any concerns which required additional mitigations.

The Mexican States of Campeche, Chiapas, and Tabasco border Guatemala. Recently Guatemala has been experiencing outbreaks of CSF in the central part of the c ountry where most of the country’s swine production occurs. CSF is considered endemic in this
area [ 65 ]. The swine industry in Guatemala is small particularly in comparison to

Mexico.

In response to this outbreak , Guatemala has vaccinated extensively a long the borders with Mexico, Honduras, and El Salvador using the PAV

- 250 vaccine to create a sanitary

buffer zone. Presently, the government of Guatemala is conducting a vaccination campaign of all production sectors in the central area of the country

.

Much of Mexico’s border with Guatemala (all of the border between Campeche, Tabasco and much of Chiapas) fronts the Petén area of Guatemala which is a sparsely

- populated rainforest with very limited number of highway entry points and a very low swine

37Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

popul ation. Feral swine have not been reported in this area and domestic swine populations are very low. During the current outbreak, t he Petén area has maintain ed an absence of suspected cases and has produced only negative results to samples collected

for t he CSF serological survey [ 58, 65 ]

. Therefore APHIS considers that the Petén area

serves as a limited natural barrier to disease transmission from Guatemala to Mexico.

The remainder of Mexico’s border with Guatemala courses through a very mountainous

re gion in the State of Chiapas westward to the Pacific Ocean. There are a limited number of highway and railway crossings between the two countries along this border. Mexico

operates a system of border crossing and internal livestock and agricultural produ ct inspection checkpoints, both federal and state, which have provided the means to control movements of animals and animal products. Checkpoints exist along highways, as well as at seaports and airports. These will be discussed later in the next section on movement
controls.

Discussion

Without a complete natural barrier limiting the movement of swine and products into Mexico, separation from adjacent regions of higher risk is dependent upon movement

controls discussed in the next section.

Movement controls and biosecurity from higher

- risk regions

Since January 2009, Mexico has considered its entire territory to be CSF

- free and

therefore removed all CSF

- related restrictions on the movement of swine, pork and pork products within the country. 5 However the authority to impose movement restrictions for the control of CSF remains as long as NOM

- 037

- ZOO

- 1995 remains in effect. Presumably this authority would be exercised if a CSF outbreak occurred and if any region within Mexico were to lose its CSF

- free status. NOM

- 037

- ZOO

- 1995 also granted SENASICA authority to prohibit the import of swine, pork or pork products from countries or regions considered by Mexico to be CSF

- affected, unless the pork or pork products were heat

- treated sufficiently to inactivate CSF virus. The draft regulatory instrument, discussed in Section 4. 2 which is to replace NOM

- 037

- ZOO

- 1995, will

preserve SENASICA ’s authority to continue to restrict imports from CSF

- affected regions and to impose appropriate movement controls in the event of a CSF outbreak.

The authority under NOM

- 037

- ZOO

- 1995 allowed CSF

- free States to restrict movement

of swine , pork and pork products from States that were in eradication or control phases in accordance with proscribed standards. Only live swine and fresh pork from other CSF

free States were allowed entry or transit through other CSF

- free States. Vehicles that moved live swine through CSF

- affected zones must have been cleaned and disinfected prior to return through a free zone.

5 Mexic o enforces movement restrictions as a component of its pseudorabies eradication program.

38Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Processe d pork products from eradication or control phase zones could enter CSF

- free zones if they were shipped from Federal inspection type establishments (TIF plants) under these conditions: 1) the facility must have had a current TIF registration; 2) the TIF p lant must have been authorized by DGSA to market their products and byproducts

into CSF

- free zones; 3) these products must have been processed according to the heat treatment standards described in the NOM (68.9o C for 30 minutes or 80.5o C for 3 minutes); 4) a veterinary certificate must have accompanied these consignments; and 5) the consignments must have been properly identified, and must have moved via sealed vehicles. Typically these were products produced in the TIF plants in the Mexico City

area a nd were shipped to the markets in other areas of the country.

Other regulatory authorities allow SENASICA to require that veterinary health

certificates be issued for interstate movement of live swine. The health certificate is required to accompany thos e shipments.

Mexico enforces animal and animal product movement restrictions through a series of inspection control posts, collectively referred to as the Sistema Nacional de Cuarentena Agropecuaria , or National System for Agricultural Quarantine. Thes e inspection control posts are authorized by DGIF and managed by SAGARPA, the state, or jointly. This system included inspection posts controlling movements into Mexico from third countries, referred to as “exterior quarantine”; movements within Mexico ba sed on regional strategies, the “interior quarantine”; and movements within and between States.

The exterior quarantine is considered the first line of defense to prevent animal diseases, exotic to the country, from entering Mexico. Compliance with the import standards and phytosanitary requirements is verified through pre

- clearance activities, document checks and physical inspections of animals and animal products. This activity is performed through by livestock health inspection personnel at maritime ports, international airports and along international borders.

To assist with the eradication campaigns for and control of various animal and plant health diseases which exist in the country, Mexico developed a system of internal quarantine cordons ( see Figure 7, page 39 ). There are 5 cordons effectively controlling movements between 6 zones within Mexico. These cordons consist of 43 control points staffed and managed by SAGARPA. The strategic purpose of these cordons is to prevent diseases, which exis t within the national territory, from spreading from the infected areas to the disease free areas and were integral in the CSF eradication campaign.

In addition to the cordon inspection posts, there are also numerous permanent inspection posts operated and staffed by CFPP personnel. These inspection posts are located on most major roadways that transit a State and operate 24 hours a day to control intra

- and interstate movement of animals and animal products. These veterinary inspectors undergo additi onal training in order to be certified in movement control. The purpose of these inspection posts is to verify compliance with animal health regulations and laws, to contribute to disease control and eradication programs, to prevent the spread of disease in the event of disease outbreak; and to maintain disease

- free zones.

39Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Figure 7: Phyto and zoosanitary quarantine lines

Source: SAGARPA [40]

40Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Discussion

The APHIS site visit team visited inspection posts throughout the country, inclu ding

CFPP

- operated posts, federal cordon inspection posts, and international checkpoints at maritime ports, international airports and land border crossings

.

At the internal inspection posts, p hysical and documentary inspection was performed on

all read ily identifiable animal and animal product shipments. Physical inspections mainly focus on verifying that the animals in transit matched the health certificate documents. Health certificate documents are issued only if the animals listed are free of signs of communicable diseases. At the inspection posts, unless there are obvious health problems, such as dead animals, the vehicles continue on to their destination. If the destination is a slaughterhouse, the animals are clinically inspected upon arrival. Inspectors indicated that if vehicles with live animals or animal products did not stop, then the inspectors with the assistance of law enforcement officers would pursue and stop these vehicles to return to the post for inspection. In addition, other veh icles, including passenger cars and buses, were inspected randomly. Records were maintained at the inspection posts in a log of all consignments transiting the post. The records indicated that any incoming swine, pork or pork products not in compliance w ith established regulations were rejected and returned to their point of origin. Monthly summary reports

were submitted to the CFPP office.

During the site visits, APHIS officials visited the international inspection control posts at the international airports in Mexico City, Guadalajara (Jalisco), Tuxtla and Tapachula (Chiapas). The primary CSF risk of international air traffic into Mexico r elates to passenger service rather than freight shipments since Mexico primarily only imports swine, pork and pork products from the United States or Canada. The passenger

- related risk would be associated with passengers carrying pork or pork products for their own consumption. These commodities could possibly contain CSF

- contaminated material. The APHIS team did not observe any deficiencies with the inspection facility, personnel or procedures. One potential concern that the APHIS team observed was the provision that a passenger could request that products prohibited entry into Mexico be stored and returned to the passenger when they departed Mexico. While the APHIS team observed good control over these held products, the team felt that the practice pre sented an unnecessary risk of potential exposure through cross

- contamination.

APHIS also visited the seaports at Manzanillo, Colima and Tapachula, Chiapas. Again there was no movement of live swine and very little movement of pork or pork products throug h these seaports. APHIS visited the land border inspection post at Tapachula, Chiapas which is the primary crossing for vehicles traveling into Mexico from Guatemala. APHIS could not identify any concerns or deficiencies with the operations and inspectio ns conducted at these inspection posts.

APHIS considers Mexico’s system of inspection posts , both internal and international, to be a strong point in the country’s animal health control infrastructure.

41Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

4.6. Diagnostic laboratory capabilities [ 36

- 60 ]

Mexico has 3 national reference laboratories: CENASA (National Animal Health Diagnostic Services) , CPA (Mexico/USA Commission for the Prevention of FMD and other Exotic Animal Diseases) , and CENA PA (National Animal Health Reference Diagnostic Services) . All three are Directorates within SAGARPA and answer directly

to SENASICA.

CENASA is responsible for the planning, organization, direction, support and evaluation

of animal health services and la boratories, and the evaluation of biological and chemical products for veterinary use. It develops and produces diagnostic reagents for enzootic diseases and for epidemiological surveillance, in particular, pseudorabies, bovine tuberculosis, brucellosis, Newcastle Disease and avian influenza. Prior to the January

2009 declaration of CSF disease

- freedom by Mexico, CENASA was also responsible for CSF surveillance; however that responsibility has now shifted to CPA. CENASA also is responsible for the traini ng and accreditation of laboratory personnel.

CPA operates a laboratory with level three biosafety (BSL3) located at Palo Alto which is

the reference laboratory for exotic diseases in Mexico, which now includes CSF. CPA has recently constructed and staff ed a network of 13 biosafety level two laboratories (BSL2) which are responsible for testing all CSF serological surveillance samples throughout Mexico. CPA’s BSL3 laboratory at Palo Alto is responsible for doing the confirmatory testing on any serologica l samples testing positive on the initial screening tests and to conduct all diagnostic testing for CSF antigen and viral isolation and sequencing.

CPA also deals with risk assessments, contingency plans, keeps SAGARPA updated on

the national and world

- wide animal health situation, lays down sanitary import conditions for animals and animal products and is a liaison with international reference laboratories regarding exotic diseases (e.g. FMD). It develops training programs on exotic disease

contr ols.

CENAPA is the n ational reference laboratory for pharmaceutical and chemical products, residues and parasitology. It establishes standards and procedures, validates methods of analysis, analyses samples from TIF establishments, lays down tolerances f or residues for particular tissues and accredits private laboratories within its field of competence.

CSF Diagnostic Competency

In 2008, APHIS conducted a site visit to the CWR of Mexico. At that time, CSF diagnostics were handled by state and private l aboratories with CENASA being the confirmatory laboratory. During that visit, VS identified concerns with laboratory diagnostic competencies related to the use of inconsistent and variable diagnostic procedures. In January 2009 when Mexico declared CSF h ad been eradicated from the country, the disease was considered to be exotic and accordingly the diagnostic responsibility shifted to the CPA laboratory network.

42Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

During 2011 at the request of SENASICA, APHIS provided technical assistance regarding CSF lab oratory diagnostic protocols and techniques, field investigation methodology and surveillance strategy. As a result of this joint effort, Mexico developed a national standard protocol for appropriate laboratory procedures and epidemiologic

follow

- up to po sitive serological findings utilizing a standardized diagnostic protocol.

In the fall of 2011 personnel from APHIS’ Foreign Animal Disease Diagnostic Laboratory (FADDL) at Plum Island extensively reviewed SENASICA’s laboratory network and their findings ( from training, site visits, document reviews, and proficiency panel testing) were favorable. FADDL reviewed the BSL3 laboratory at Palo Alto and verified their competency to conduct CSF confirmatory testing with an effective date of Sept. 13, 2011 ( see App endix 1 ). APHIS considers confirmatory tests conducted after

that date to be valid. FADDL technicians also reviewed several CPA BSL2 laboratories in Jalisco, Sonora, Puebla, Chiapas, and Veracruz, during multiple site visits conducted from February 2011 through December 2012 and verified their compliance with established diagnostic protocols.

Discussion

APHIS is satisfied with the improvements made to Mexico’s CSF diagnostic capabilities and is confident in the CSF test results reported by CPA on samples processed after September 13, 2011. CPA personnel have demonstrated proficiency in CSF diagnostics

an d the CSF confirmatory processes and procedures are in compliance with international

standards. While APHIS has confidence in the diagnostic test results, in many of these

suspect cases

, investigators did not collect the most appropriate samples or , due to lack of

reliable animal identification

, it could not be verified that the samples they collected were taken from animals most likely to be harboring the virus (if it were present) at the time of

collection.

4. 7

. S urveillance practices [ 36

- 60 ]

Active surveillance

An ac tive CSF surveillance program is conducted in Mexico under the authority of

NOM

- 037

- ZOO

- 1995

. States maintain their CSF

- free status by conduct ing annual serological sampling surveys in comme rcial and backyard herds. In addition,

SENASICA also collects samples for slaughterhouse surveillance

. Each year

SENASICA determines the CS F sampling targets for each state and coordinates the implementation with State government s and CFPP based on the state’s swine population

and risk considerations

. Since the 2009 declaration of disease freedom, SENASICA has been reducing annually the numb er of samples collected for CSF surveillance, except for

increased targeted surveillance conducted along Mexico’s southern border in response to the CSF outbreak occurring in Guatemala.

43Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

At the time of the site visit to the CWR in April 2012, t he CSF surve illance sampling for

commercial herds that SENASICA was following for the 2012 survey was designed to detect 3% threshold premises level prevalence with 99.9% confidence, assuming a test sensitivity of 98% based on the national swine population

. However a fter considering a recommendation by the APHIS team, SENASICA adjusted the sampling targets to

achieve a detection threshold of 1% prevalence with 95% confidence level for the CWR

. APHIS recommended more intensive surveillance of the region because of the region’s high concentration of commercial swine farms and large swine population. The CWR is more likely than other regions to export pork.

A stratified random sampling protocol was used for the backyard herds to detect 1 % prevalence with 97 % confidence . SENASICA determined the number of backyard herd samples to collect annually in each State. SENASICA provides guidance to State and

Committees on risk

- based selection factors so they can target sampling selections

. Usually five pigs per backyard herd we re sampled or all pigs are sampled if there are less than 5 pigs on the premises

.

For the last couple of years, SENASICA has conducted slaughter surveillance in TIF slaughter plants and in 2012 began collecting samples in municipal plants as well.

SENA SICA selects which plants to sample based on their assessment of risk factors and establishes a target number for samples to collect from each plant. The SENASCIA inspectors at each plant developed their own selection criteria to choose which lots to

samp le and when. The APHIS team found variability between the slaughterhouses in the selection criteria they followed ; generally inspectors selected lots and animals to sample

based on convenience

.

Summaries of the surveillance sampling scheme by State for the last two years are provided in Tables 3 and 4 (pages 4 4

- 4 5 ) . The diagnostic test results of positive or suspicious findings for the active surveillance are listed in Table 5 (page 4 6 )

.

Passive surveillance

The level of passive surveillance activity varied among the States under evaluation. In general states that have either a large swine populations or have most recently gained

their CSF

- free designation were more likely than other States to report passive surveillance investigations. The diagnostic test results from passive surveillance investigations are summarized by State in Table 6 (page 4 7 )

.

44Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Table 3

. CSF surveillance sampl ing scheme , 2011

STATE Commercial Backyard Slaughterhouses Hunting Reserves

#

Units # Samples #

Units # Samples #

Units # Samples #

Units # Samples
Aguascalientes 7 294 60 300 0 0 n/a n/a

Chiapas 13 546 90 450 0 0 0 0

Coahuila 1 42 60 300 1 84 n/a n/a

Colima 12 504 60 300 n/a n/a 1 5

District Federal n/a n/a 60 300 n/a n/a n/a n/a

Durango 3 126 90 450 2 22 n/a n/a

Guanajuato 186 7,812 60 300 4 444 n/a n/a

Guerrero 7 294 60 300 0 0 n/a n/a

Hidalgo 16 672 60 300 0 0 0 0

Jalisco 271 11,382 60 300 2 72 0 0

Mexico 8 336 60 300 3 648 0 0

Michoacán 84 3,444 60 300 0 0 n/a n/a

Morelos 5 210 60 300 n/a n/a n/a n/a

Nuevo Leon 14 588 60 300 2 468 n/a n/a

Oaxaca 9 378 60 300 0 0 n/a n/a

Puebla 17 714 60 300 1 120 0 0

Querétaro 13 546 60 300 1 216 n/a n/a

San Luís Potosí 3 126 60 300 0 0 n/a n/a

Tabasco 1 42 90 450 n/a n/a n/a n/a

Tamaulipas 6 252 60 300 0 0 n/a n/a

Tlaxcala 7 245 60 300 0 0 0 0

Veracruz 30 1260 60 300 1 84 1 5

Zacatecas 2 84 60 300 0 0 0 0

Source: SAGARPA [ 49

- 60 ]

45Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Table 4

. CSF surveillance sampl ing scheme , 201 2

STATE Commercial Backyard Slaughter houses Hunting Reserves

#

Units # Samples #

Units # Samples #

Units # Samples #

Units # Samples
Aguascalientes 2 84 30 150 1 120 n/a n/a

Chiapas 2 84 120 863 2 134 1 5

Coahuila 1 42 30 150 2 240 n/a n/a

Colima 3 126 30 150 1 120 0 0

District Federal n/a n/a 30 150 n/a n/a n/a n/a

Durango 2 84 60 300 3 300 n/a n/a

Guanajuato 49 2,058 60 300 9 840 n/a n/a

Guerrero 2 84 30 150 2 180 n/a n/a

Hidalgo 4 168 30 150 1 120 1 5

Jalisco 74 3,108 60 300 26 2,760 2 10

Mexico 3 126 30 150 5 420 3 15

Michoacán 20 840 60 300 6 660 0 0

Morelos 1 42 30 150 1 120 n/a n/a

Nuevo Leon 3 126 30 150 2 180 n/a n/a

Oaxaca 2 84 30 150 1 120 n/a n/a

Puebla 4 168 30 150 3 400 2 10

Querétaro 3 126 30 150 2 180 n/a n/a

San Luís Potosí 1 42 30 150 1 120 n/a n/a

Tabasco 1 42 89 445 n/a n/a n/a n/a

Tamaulipas 1 42 30 150 2 240 n/a n/a

Tlaxcala 1 42 30 150 1 120 3 15

Veracruz 7 294 30 150 3 300 1 5

Zacatecas 1 42 30 150 1 120 1 5

Source: SAGARPA [ 49

- 60 ]

46Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Table 5

. Active CSF surveillance samples with positive serological findings

, 2011

- 2012

STATE YEAR Prod.Unit (PU) POSITIVE

SAMPLES ELISA POSITIVE

SAMPLES IP POSITIVE

SAMPLES SN POSITIVE

SAMPLES RT

PCR POSITIVE

SAMPLES VI

Aguascalientes 2011 1 1 0 n/a 0 n/a

2012*

- - - - - 0
Chiapas 2011 103 1 0 n/a 0 n/a

2012* 219 11 8 7 0 n/a

Coahuila 2011 61 0 n/a n/a 0 n/a

2012* 8 0 n/a n/a 0 n/a

Colima 2011 1 1 1 0 0 0

2012** 1 9 7 1 0 0

District Federal 2011 0 n/a n/a n/a n/a n/a

2012* 0 n/a n/a n/a n/a n/a

Durango 2011 125 0 n/a n/a 0 n/a

2012* 56 0 n/a n/a 0 n/a

Guanajuato 2011 5 11 9 7 0 0

2012*

- - - - - -
Guerrero 2011 67 1 1 1 0 0

2012* 34 0 n/a n/a n/a n/a
Hidalgo 2011 76 14 12 8 0 0

2012* 443 0 n/a n/a 0 n/a

Jalisco 2011 25 37 5 1 0 0

2012*

- - - - - - Mexico 2011 5 24 18 16 0 0

2012* 4 4 0 n/a n/a n/a

Michoacán 2011 11 22 7 1 0 0

2012*

- - - - - - Morelos 2011 65 1 1 1 0 0

2012* 32 4 2 0 0 0

Nuevo Leon 2011 0 n/a n/a n/a n/a n/a

2012* 1 47 35 0 n/a 0

Oaxaca 2011 75 2 0 n/a 0 n/a

2012* 33 0 n/a n/a 0 n/a

Puebla 2011 78 0 n/a n/a n/a n/a

2012* 33 1 0 n/a n/a n/a

Querétaro 2011 2 2 0 n/a n/a n/a

2012*

- - - - - -
San Luís Potosí 2011 0 n/a n/a n/a n/a n/a

2012*

- - - - - - Tabasco 2011 92 0 n/a n/a n/a n/a

2012* 91 1 1 1 0 0
Tamaulipas 2011 66 0 n/a n/a n/a n/a

2012* 33 0 n/a n/a n/a n/a

Tlaxcala 2011 67 0 n/a n/a n/a n/a

2012* 19 2 2 0 0 0

Veracruz 2011 91 2 2 0 0 0

2012* 41 0 0 0 0 0

Zacatecas 2011 0 0 n/a n/a n/a n/a

2012*

- - - - - -

- data not available at time of site visit

* January to September 2012 ** January to May 2012

Source: SAGARPA [ 49

- 60 ]

47Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Table 6

. Passive CSF surveillance samples with positive serological findings

, 2011

- 2012

STATE YEAR Prod.Unit (PU) SAMPLES

TAKEN POSITIVE

SAMPLES

ELISA POSITIVE

SAMPLES

IP POSITIVE

SAMPLES

SN POSITIVE

SAMPLES

RT

- PCR POSITIVE

SAMPLES

VI

Aguascalientes 2011 0 0 n/a n/a n/a n/a n/a

2012*

- - - - - - - Chiapas 2011 5 68 0 n/a n/a 0 n/a

2012* 7 84 0 n/a n/a 0 n/a

Coahuila 2011 0 0 n/a n/a n/a n/a n/a

2012* 0 0 n/a n/a n/a n/a n/a

Colima 2011 0 0 n/a n/a n/a n/a n/a

2012*

- - - - - - - District Federal 2011 2 21 0 n/a n/a 0 0

2012* 0 0 n/a n/a n/a n/a n/a

Durango 2011 0 0 n/a n/a n/a n/a n/a

2012* 0 0 n/a n/a n/a n/a n/a

Guanajuato 2011 1 10 0 n/a n/a 0 n/a

2012*

- - - - - - -
Guerrero 2011 1 2 n/a n/a n/a 0 n/a

2012* 5 37 0 n/a n/a 0 n/a
Hidalgo 2011 3 92 0 n/a n/a 0 0

2012* 0 0 n/a n/a n/a n/a n/a

Jalisco 2011 6 238 0 n/a n/a 0 0

2012*

- - - - - - - Mexico 2011 6 449 18 14 12 0 0

2012* 0 0 n/a n/a n/a n/a n/a

Michoacán 2011 0 0 n/a n/a n/a n/a n/a

2012*

- - - - - - - Morelos 2011 1 5 0 n/a n/a n/a n/a

2012* 10 48 0 n/a n/a 0 0

Nuevo Leon 2011 0 0 n/a n/a n/a n/a n/a

2012* 0 0 n/a n/a n/a n/a n/a

Oaxaca 2011 2 7 0 n/a n/a n/a n/a

2012* 2 17 0 n/a n/a 0 n/a

Puebla 2011 1 4 n/a n/a n/a 0 n/a

2012* 0 0 n/a n/a n/a n/a n/a

Querétaro 2011 2

- 0 n/a n/a 0 0

2012*

- - - - - - - San Luís Potosí 2011 0 0 n/a n/a n/a n/a n/a

2012*

- - - - - - - Tabasco 2011 3 16 0 n/a n/a 0 0

2012* 6 40 0 n/a n/a 0 0
Tamaulipas 2011 0 0 n/a n/a n/a n/a n/a

2012* 2 10 0 n/a n/a n/a n/a

Tlaxcala 2011 1 3 0 0 0 0 0

2012* 0 0 n/a n/a n/a n/a n/a

Veracruz 2011 0 0 0 0 0 0 0

2012* 0 0 0 0 0 0 0

Zacatecas 2011 2 10 0 n/a n/a n/a n/a

2012*

- - - - - - -

- data not available at time of site visit * January to September 2012 ** January to May 2012

Source: SAGARPA [ 49

- 60 ]

48Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

In accordance with NOM

- 037

- ZOO

- 1995, w hen a positive result is obtained through serolog ical screening tests , or when a case of CSF is suspected on a farm , the animal

owner , the attending veterinarian, and the laboratory are required by Federal law to immediately report the suspicion or finding to the SAGARPA State delegation

. Immediately up on suspicion, a precautionary quarantine is to be imposed on the affected premises and an official epidemiological investigation is to be conducted

.

The APHIS site visit team examined multiple case investigation reports in each of the

states visited. The results of those audits are discussed previously in this document ( see discussion in Section 4. 3

. Disease history and vaccination practices ).

Discussion

The implication regarding the findings of exposure to CSF antigen from an undetermined

source wa s previously discussed and will be considered in the subsequent risk estimation. However it is important to point out that until the source of these exposures is determined

APHIS considers it necessary for Mexico to maintain the current level of CSF

surve illance, especially if targeted surveillance strategies can be utilized to further leverage the necessary resource investment.

During the site visits, the APHIS team made several specific recommendations regarding

surveillance which are:

• For backyard and semi

- technified farms, the guidance given to field personnel collecting samples should emphasize that the sample size of 5 is a minimum sample size, and that field personnel should use their discretion to collect more samples from larger farms in this cat egory.

• One epidemiologic unit should be considered one sampling unit. Field personnel should not collect samples from multiple owners within an epidemiologic unit for the purpose of filling the sampling quota.

• For s laughter surveillance , s ick animals and dead animals (any cause) should be selected, if available. APHIS recommend ed that any animals that die in the slaughter channel should be sampled and tested for CSF. Antigen tests are appropriate for testing sick and dead animals.

• If no sick or dead animals are available, slaughter surveillance samples should be selected randomly from multiple lots, rather than from a single lot. Antibody tests are appropriate for animals with no clinical signs.

• The records examined indicated that l aboratory diagnosticians were often not
included in the investigation process . Consistent and systematic communication between laboratory diagnosticians, field investigators, and SENASICA

, Epidemiological Surveillance Direction (DIVE) are beneficial to fu lly understand the epidemiology of each case investigation. APHIS recommends that a ll parties

be consulted in the case investigation process prior to closing a case

.

Although some of the findings detected through Mexico’s CSF surveillance program

raise concern, APHIS acknowledges that the capacity to make those detections are a credit to the strength of the program which APHIS believes to be sound.

49Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

4. 8

. Emergency preparedness and response [ 36

- 60 ]

In general whenever an animal disease exotic to Mexico , including CSF, is detected it must be immediately reported to the Secretariat of Agriculture and Rural Development in

accordance with NOM

- 046

- ZOO

- 1995. This NOM describes an animal health emergency

infrastructure that would be activated

.

DINESA is the National Mechani sm for Emergencies in Animal Health (Dispositivo Nacional de Emergencia de Salud Animal), which is activated once the presence of an exotic disease or pest is confirmed within the national territory, according to the general and/or specific emergency plan to control and

- or eradicate the exotic disease in case. DINESA requests the collaboration of different Federal or State Branch Offices in order

to contain the outbreak and avoid serious national economic losses.

Mexico has an established national system f or surveillance and reporting of exotic animal

diseases operated by SAGARPA in collaboration with the Mexico

- U nited S tates
Commission for the Prevention of Foot and Mouth Disease and Other Exotic Animal

Diseases (CPA)

. Since the January 2009 declaration

, CSF virus is considered to be

exotic to all of Mexico

.

Operating at the State level under the direction of DINESA, are the Grupos Estatales de Emergencia en Salud Animal (State Animal Health Emergency Groups, GEESAs). In the event of an animal emergenc y, a GEESA is activated to function at the local level to quickly and effectively respond to the outbreak. A GEESA includes specialized technical personnel who have experience with animal health and outbreak control. This group is composed of individuals from Federal and State government, CFPP, industry, and swine producers. The GEESA includes both official and private veterinarians who receive periodic training in foreign animal diseases and participate in simulation exercises. If necessary, the milita ry can assist the GEESA in animal health emergencies.

Under the authority of NOM

- 037

- ZOO

- 1995 w henever CSF is suspected, SAGARPA

must immediately be notified and a precautionary quarantine is to be implemented in the focal and perifocal area to include the affected, exposed and at risk premises. Field investigations are coordinated by CPA through their regional network of field epidemiologists. CPA works with State authorities to conduct this activity. If CSF is confirmed by the CPA l aboratory then the quarantine would become definitive.

Movement controls are to be implemented, sick animals are to be killed, dead animals are to be sanitarily disposed, and an epidemiological investigation is to commence

. The Dispositivo Nacional de Em ergencia de Sanidad Animal ( National Animal Health Emergency Operation or DINESA) is to be activated. DINESA functions to control and

eradicate the outbreak in accordance with the National CSF Emergency Plan.

Under the current authority

, once the exten t of the outbreak is known, a determination

will be made to assess the financial and technical feasibility of depopulating affected and exposed pr emises. If feasible, a stamping

- out without vaccination policy will be implemented and indemnity will be paid to producers , likely out of the S tate’s insurance

50Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

plan or contingency fund. If depopulation is not feasible

, then SENASICA has the option to downgrade the CSF

- status of the S tate from “CSF

- free zone” to “CSF

- control zone”

status , designations utiliz ed during Mexico’s National CSF Campaign. Those states

would then have to follow procedures established in NOM

- 037

- ZOO

- 1995 to regain

“CSF

- free zone ” recognition as the situation improved

. If a stamping out without vaccination pol icy is implemented and the affected premises are cleaned, disinfected and repopulated in accordance with the National CSF Emergency Plan, then six months must pass without evidence of CSF virus before the State could re gain the “CSF free

- zone”

status

.

Discussion

The APHIS site visit team observed a close association and cooperation between the

F ederal

, S tate and municipal government officials

, the CFPP staff and swine producers

. This cooperation was especially effective in the operation of animal heal th checkpoints which would provide an effective means to control swine movements in the event of a

CSF outbreak

.

As discussed in a previous section, APHIS is concerned about the thoroughness of trace

in and trace

- out activities of some suspect case inve stigations. APHIS has consistently recommended to SENASICA that improvements be made in this regard. This problem has the potential to allow pockets of CSF virus to go undetected and potentially spread further. The result of such would certainly complic ate any emergency response once the

outbreak is detected. Otherwise, APHIS could not identify any other concerns with this

factor.

4. 9

. Release Assessment Conclusions

Serologic evidence of exposure to CSF virus has been found in a number of Mexican States. The specificity of the antibodies was demonstrated by comparative neutralization tests; however, no virus has been detected. It has not been possible from the data

av ailable to determine whether these antibodies were produced after infection with a field strain of CSF virus or after vaccination with CSF vaccine. These findings increase the level of uncertainty regarding the presence or absence of CSF virus in Mexico.

APHIS considers three possible explanations for the high serum neutralization ( SN ) titers found in the sera of pigs during several active and passive surveillance investigations: exposure to CSF vaccine virus; exposure to field strain CSF virus; and fa lse positive test

results.

APHIS concludes that for all of Mexico except Chiapas the most likely explanation for the serological findings is residual vaccine titers and/or continued illegal use of vaccine.
However, the pattern of findings in Chiapas

, a long with its close proximity to known CSF viral activity in Guatemala

, prevents APHIS from concluding that antibody detection in Chiapas is due solely to exposure to vaccine virus.

51Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Although APHIS is unable to recognize these States as free of CSF due to the uncertainty surrounding the serological findings, APHIS concludes that the risk of importing CSF

infected pork and pork products from the currently unrecognized States of Mexico, with the exception of Chiapas, is low and can be mitigated if certain re quirements are met on the farms of origin and in the slaughterhouses and processing plants. These requirements are described below under Mitigations.

APHIS observed many strong points in Mexico’s veterinary infrastructure, diagnostic laboratory network, and commercial farm biosecurity. While finding evidence of CSF antigen exposure detected through Mexico’s CSF surveillance program raises concern, APHIS recognizes that the capacity to make those detections are a credit to the strength

of the surveillance program which APHIS believes is sound at the current level. APHIS also acknowledges the ongoing enhanced surveillance activities conducted by SENASICA in Chiapas and other states bordering Guatemala in response to the CSF

outbreaks there. APHIS also con siders Mexico’s system of inspection posts, both internal and international, to be a strong point in the country’s animal health control

infrastructure.

However, APHIS identified three risk factors associated with importing Mexican

- origin pork and pork pr oducts into the United States from a region in Mexico

. APHIS discusses these risk factors in the context of the potential for counterbalancing circumstances or applying appropriate risk mitigations to further reduce the risk of introducing and establish ing CSF in the United States. The risk mitigation procedures, which will be defined in the proposed rule, include regionalization of Mexico to recognize a CSF

- low

- risk region and certifications by SENASICA to provide confidence that pork and pork products meet acceptable export criteria. The CSF

- low

- risk region in Mexico recognized by APHIS includes all of Mexico except the 9

- states currently recognized as CSF

- free and the State of Chiapas for which APHIS considers the CSF risk to be unacceptable.

Risk Factors

Uncertainty regarding positive serological results

Serologic evidence of exposure to CSF virus has been found in a number of Mexican

States as recently as 2012 . The specificity of the antibodies was demonstrated by comparative neutralization tests; however, no virus has been detected. I t has not been possible from the data available to determine whether these antibodies were produced

after infection with a field strain of CSF virus or after vaccination with CSF vaccine. So

far , antigen test results (i.e. PCR and viral isolation) have been negative. However, it is

difficult to conclude that CSF virus is absent in these suspect cases because investigators

did not collect or , due to lack of reliable animal identification

, it coul d not be verified that they collected the most appropriate samples from the animals most likely to be harboring

the virus (if it were present) at the time of collection.

52Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

Therefore because the presence of CSF antibody detection in multiple areas of Mexico cannot be explained by the evidence presented, APHIS conclude d that these findings

increase the level of uncertainty regarding the presence or absence of CSF virus in the

country.

For all states but the State of Chiapas, APHIS considers the most likely explanation for the CSF antigen exposure is related to residual vaccine titers and illegal use of vaccine.
However, the pattern of findings in Chiapas, along with its close proximity to known CSF viral activity in Guatemala, prevents APHIS from considering it to be likely that antibody detection in Chiapas is due solely to exposure to vaccine virus.

APHIS considers the CSF

- status of Chiapas to be higher risk than the rest of Mexico for several reasons. In 2012, SENASICA identified a cluster of 7 premises where extremely high CSF antibody titers (most in excess of 1:25 6 0) were detected. These titers are indicative of CSF antigen exposure but the nature of the exposure is unexplained . These premises are located in close proximity to the border with Guatemala where CSF outbreaks have recently occurred. SENASICA recognizes that Chiapas as a high risk region where CSF is more likely to be reintroduced and accordingly has targeted the st ate
for increased surveillance.

All vehicular traffic between Guatemala and Mexico enters through Chiapas. SENASICA maintains several inspection posts along those highways that serve as the primary mitigation to deter and intercept illegal movement of live swine, people and

vehicles.

Another concern is that Chiapas only recently (late 2012) made the recommended changes to their CSF diagnostic protocol; therefore, there is some uncertainty to the laboratory results and epidemiological investigations conducted in 2011 and early 2012. SENASICA has recently made changes in the animal health leadership of Chiapas in an attempt to address the deficiencies in their CSF surveillance activities.

Incomplete epidemiological investigations of CSF suspect cases

During the last several years, SENASICA has improved the quality and consistency of field epidemiological techniques and standards. However, these improvements have not
been uniform ly implement ed in all areas of the country

. APHIS is concerned about

co ntinued problems with the quality of some epidemiological investigations of CSF suspect cases. Specifically, APHIS is concerned about the thoroughness of the investigations and lack of trace

- in and trace

- out activities of some suspect case s

. In some inve stigations staffs have not selected proper animals to sample or have not chosen the most appropriate diagnostic test to run on the samples collected. For example, several

cases involved swine in which high titers to CSF antibodies had previously been

dete cted ; these were selected for sampling to test for CSF antigen and/or vir us isolation long after live virus , if it had been present, would likely have been cleared from the

animal. In general, CSF antibodies are detectable 10 to 14 days post infection (dp i) at the

53Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

earliest, while the ability to isolate virus from tonsil tissue begins declining simultaneously with the appearance of antibody [ 3

- 8 ]. 6

This problem could limit SENASICA’s ability to confirm or exclude CSF virus activity

in accordance with international standards. However

, APHIS acknowledges the ongoing efforts of SENASICA to address this issue, as evidenced by its recent attempts to correct investigation deficiencies.

Proximity to CSF viral activity in neighboring countr ies

The existence of common land borders with CSF

- affected regions in the south presents a

risk for re

- introducing CSF into Mexico. This factor is substantially mitigated because

Mexic o prohibits the importation of swine, pork

, and pork products from countries it

considers CSF

- affected, including Belize and Guatemala. However, swine, pork, or pork products could be moved illegally into Mexico . The legal movement of people, vehicles

,

or equipment that may be contaminated with undetected CSF virus may also reintroduce

CSF into Mexico.

Mitigation s

Because of these risk factors, APHIS determined certain restrictions are necessary to mitigate the risk of release of CSF virus via fresh po rk and pork products originating in

and imported from a CSF

- low

- risk region in Mexico. These restrictions will require

SENASICA to certify certain conditions on the farm of origin and at the slaughterhouse and processing plants.

Therefore, APHIS proposes to: a) Allow importation of Mexican

- origin pork and pork products from a CSF

- low

risk region in Mexico subject to specified conditions

. b) R estrict imports of pork and pork products originating in and imported from a CSF

- low

- risk region in Mexico into the United States by requiring pork be

6 The clinical signs and outcomes of CSFV infections vary considerably depending on the strain of virus as well as host and environmental factors. In general, antibodies are detectable 10 to 14 days post infection (dpi) at the earliest. In pigs with chronic CSF, neutralizing antibodies are detectable at the end of the first month post infection but disappea r a few days afterwards [ 3

- 6, 8 ].

Antigen detection is even more variable depending on the virus strain. For highly virulent CSFV strains (such as the Brescia strain)

, animals die within 9 to 14 dpi and virus is detected 2 t o 4 dpi onwards

. However, mode rately virulent CSFV strains (like the Haiti strain) can be detected up to 28 dpi in tonsils using the PCR . L ow virulent strains, like the Bavaro, have been detected in blood for up to 29 dpi, in

tonsil s scraping s for 21 dpi

, and up to 70 dpi in hist o logi cal sections of tonsil tissue [ 3, 6

- 8 ].

T he times for virus detection in the same samples using the vir us isolation (VI) test proved to be shorter. Some authors have explained this effect as the result of the formation of virus

- antibody complexes . The VI test may start losing sensitivity simultaneously with the appearance of antibodies , around 14 dpi [ 6,7 ].

54Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________________________________________________

de rived from swine raised on farms that operate under a high level of biosecurity

and where CSF antigen exposure has not been detected

. c) Require pork or pork products originat ing in and imported from a CSF -low- risk region in Mexico be derived from swine not commingled with swine not originat ing from herds operating under the required sanitary standards. d) Require pork or pork products originat ing in and imported from a CSF -low- risk region in Mexico not be co mmingled with pork or pork products derived from

swine not orig inating from herds not reared under the required level of sanitary

standards. e) Apply restr ictio n s descr ibed i n 9 CFR 94.32 to pork and pork products originating in and imported f

rom a CSF -low-risk region in M ex ico

. f) R equire the establishment slaughtering swine to allow periodic on- site evaluation and subsequent inspection of its facilities, records, and operations by an APHIS representative.

A PHIS proposes that SENASICA certify pork and pork products originating from a CSF

low-risk region in Mexico as derived from swine reared on premises meeting the following standards for sanitary conditions and biosecurity and not commingled with swine reared under less stringent standards:

1. He rd is tested annually for CSF and the results show absence of antibodies to CSF. The sampling protocol includes:

a. Serologic testing of the herd, using a testing protocol that allows

differentiation between CSF antibodies and cross- reactions with antibodies to other pestiviruses. Sample size should be adequate to detect

5 percent prevalence at a 95 percent confidence level.

b. Samples from the herd may be collected at the slaughterhouse or the farm.

c. Any sick pigs showing clinical signs consistent with CSF are sampled and tested for CSF antigen at any time . Any freshly dead pigs or pigs needing

to be euthanized are necropsied and complete diagnostics for CSF performed. 2. Biosecurity measures include:

a. Containment of domestic pigs to prevent exposure to other swin e, wildlife or swine products. b. Cleaning, disinfection, and control of movement of vehicles enter ing farms or transport ing swine.

c. Control of personnel entering the farm and keeping a written visitors’ log. d. Training of personnel and farm veterinarians in awa reness of risk of fomite spread and clinical signs of CSF.

e. Recordkeeping of animal movements into and out of the farm (including species other than swine).

f. Prohibition of swill feeding on the farm.

g. Documentation of adequate pest control on the farm. h. Prohibition of farm personnel from owning or working with other swine or in swine slaughter facilities.

55Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________________________________________________

3. R eplacement stock and swine semen are sourced only from herds of equivalent sanitary status not located in regions considered by APHIS to be CSF- affected or

a re replacement stock or semen -donor boars that have tested negative for CSF while being quarantined before introduction to the destination farm or semen collection center

. 4. Herds are not epidemiologically linked to CSF outbreaks and have not been located within protection and surveillance zones established in response to CSF outbreaks within the previous 12 months.

5. Herds are inspected annually by SENASICA

, which verifies co mpliance with the

above conditions.

A PHIS will also propose special restrictions requiring pork or pork products originat ing in and imported from a CSF -low-risk region in Mexico to be derived from swine not commingled with swine originating from herds not meeting these sanitary standards

. The proposed rule will also require pork or pork products originating from a CSF -low- risk region in Mexico for export to the United States to not commingle with pork or pork products derived from swine originating fro m herds not meeting the sanitary standards

described above

.

APHIS a lso intends to impose special restrictions described in 9 C FR 94.32 . APHIS

considers M exico to me et t he criteria described i n this r egulation be caus e Mexico s hares

a c ommon land border w ith countries A PHIS do es not r ecognize a s C SF- free. These

restrictions pr ohibit t he i mportation of por k and pork products de rived from s wine originating in or ev er living in regions A PHIS considers CSF

- affected. P ork or por k products m ust de rive f

rom s wine slaughtered at a federally

- inspected es tablishment in a region of M exico from w hich pork or pork pr oducts ar e eligible f or export to the U nited

States . Further, the regulation prohibits t he i mportation of por k or por k products t hat might have commingled with or be contaminated by pork or por k products de rived from

swine or iginating in C SF

- affected r egions.

A PHIS concludes these mitigations will greatly reduce the likelihood that pork and pork products originating in and imported from a CSF -low-risk region in Mexico might be infected with or contaminated by CSF virus.

C onclusion of Release Assessment

A PHIS identified risk factors associated with importing Mexican

- origin pork and pork products into the United States from a CSF -low- ris k region in Mexico and proposed mitigations to address these risk factors. APHIS concludes these mitigations will greatly

reduce the likelihood that pork and pork products originating in and imported from a CSF -low-risk region in Mexico might be infected w ith or contaminated by CSF virus.

56Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________



## Section 5. Exposure Assessment

An exposure assessment as defined by the OIE describes the biological pathway(s) necessary for exposure of animals and humans in an importing country to the hazards released from a given risk source, and estimates the likelihood of the exposure(s) occurring [ 2 ]

. APHIS' regulatory authority is limited to animal health

, so pote ntial risks to animals are the primary focus of this evaluation.

APHIS considers that the most likely pathway of exposure of domestic swine to CSF virus in pork and pork products is through feeding of contaminated food waste to swine
[ 66 ]

.

5.1. Waste Feeding t o Susceptible Swine

The likelihood of exposure of susceptible species to virus

- infected meat was evaluated in previous APHIS studies. In 1995, APHIS conducted a pathway analysis to estimate the likelihood of exposing swine to infected waste [ 67 ] . The analysis included two pathways for exposure of swine to contaminated waste; namely, exposure associated with illegal imports for personal use , and exposure associated with legal imports. The latter is the exposure pathway that would be applicable to importing pork or pork products from a CSF

- low

- risk region in Mexico

. With 95% confide nce, APHIS estimated that 0.023 % or less of plate and manufacturing waste would be inadequately processed prior to fe eding

to swine [ 67 ]

. Based on this fraction, less than 1 par t in 4,300 (reciprocal of 0.023

percent ) of imported meat is likely to be fed to swine as inadequately cooked wa ste.

APHIS conducted a survey in 2001 of the U.S. swine waste

- feeding sector to update a similar study done in 1994 [ 68 ]

. Based on this survey, APHIS estimated that the proportion of plate and manufacturing waste fed to swine diminished by about 50 %

between 1994 and 2001 due to a decrease in the number of waste

- feeding premises. The study also found that:

1. Several more U.S. States prohibited feeding food wastes to swine;

2. The number of waste

- feeding premises in the continental United States decreased by 40.5% from 1994

- 2001, and in Hawaii and Puerto Rico decreased by 37.5% and 52.3%, respectively; and

3. Institutions and restaurants provide nearly 90% of all plate waste fed t o swine.

APHIS considers that prohibiting the feeding of unprocessed plate waste to swine has

further contributed to the reduction of waste

- feeding to swine. W aste

- feeder operations must be licensed and inspected regularly by U

. S

. D epartment of A griculture inspectors (9

CFR § 166). The licensing process requires that producers adequately cook the waste fed

to swine using methods designed destroy foreign animal disease agents.

57Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

5. 2 . Conclusion

APHIS assessed the likelihood of exposure of suscepti ble swine populations in the United States to CSF virus in fresh pork and pork products originating in and imported from a CSF

- low

- risk region in Mexico. Studies of the U.S. waste

- feeding sector led APHIS to conclude susceptible swine in the United States are unlikely to be exposed to the CSF virus via waste feeding.

58Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________



## Section 6. Consequence Assessment

This consequence assessment, conducted in accordance with OIE guidelines, describes the consequences of introducing CSF into the United States [ 2 ]

. The magnitude of the biologic and economic consequences following an introduction of CSF would depend on the location of the introduction; the virus serotype introduced; the rate of virus spread; the ability to detect the disease rapidly; livestock demog raphics and movement patterns; and the ease of control and eradication. Additionally, restrictions imposed by international trading partners may result in severe economic losses and other hardship to otherwise unaffected industry segments.

6.1. Effects on animal health and production

CSF is a highly contagious and frequently fatal viral disease of swine. Introduction into the United States would likely result in high rates of infection among exposed swine [ 72 ]

. The severity and clinical presentation of CSF depends largely on the age of the animal and virulence of the viral strain, and can range from severe disease with up to 90% mortality to infections t hat are essentially asymptomatic. Young animals usually more severely affected than older animals. Low virulence strains may manifest primarily as poor reproductive performance and birth of piglets with neurologic defects [ 14

, 72 ] . The effects on animal production parameters will vary based on the severity of disease; however, losses of animals, decreased growth efficiency, and reproductive losses could be expected in infected populations.

6.2. Control and eradication costs

Outbreaks of foreign animal diseases in previously free regions have historically been associated with large economic costs, including production and trade losses, as w ell as the costs of control and eradication. The overall costs of control and eradication depend magnitude of the outbreak and the control options utilized. For CSF

- free countries like the United States that have a substantial export market for live swi ne, pork and pork products, the preferred option for control and eradication has traditionally been to stamp

out infected herds without the use of vaccine.

Potential costs include disease control measures such as imposing quarantines and

movement controls, direct costs related to stamping out of affected and contact herds, indemnity payments, surveillance and laboratory testing. The total cost of disease control and eradication, however, will depend on numerous factors, including the extent of

spr ead and the prevalence of infection prior to detection, the density and types of populations of susceptible animals in affected regions, and which control and eradication strategies are ultimately implemented. Although the amount may be variable, it is l ikely that the cost of control, eradication, and compensation will be significant.

The most recent outbreak of CSF in the United States occurred in 1976. The costs of a CSF eradication program conducted from 1961 to 1976 was approximately $140 million

at that time [ 73 ] . No recent data are avai lable regarding costs of control and eradication in

59Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

the United States. For illustration, reported costs of CSF control and eradication in other

countries are summarized below.

Saatkamp et al (2000) reviewed the economic aspects of control of small and l arge CSF outbreaks in the European Union (EU) from 1990 to 1997. For the largest outbreak, involving 429 herds over 14 months, the cost of removing affected swine was the equivalent of $401 million U.S. dollars, slaughter for welfare purposes cost $1.1 bi llion, and program operational costs were $126 million. Overall, the outbreak cost pig producers $669 million, the national government $217 million, and the EU $760 million
[ 74 ] . Approximately 10 million pigs were destroyed during the outbreak, primarily for welfare reasons (being in overcrowded conditions, or being overweight for slaughter)
[ 75 ] . The total cost of smaller outbreaks ranged from $10.2 million (8 affected herds over 2 months) t o $196 million (113 affected herds over 10 months) [ 74 ] . In all of these cases, the slaughter of swine, either for welfare reasons or because of infection or high risk, accounted for the vast majority of the estimated costs.

The potential for rapid escalation of costs related to an outbreak is high since CS F is highly contagious and likely to spread rapidly. In addition, some CSF virus infections may result in mild or absent clinical signs, and could potentially spread without detection for some time. Lack of sufficient data; the unpredictability of the cl inical course and patterns of spread of infections; and the complexity of the factors involved in spread, control and eradication make reliable estimation of the potential costs of control and eradication of CSF in the United States difficult or impossible . Results of this qualitative assessment, however, suggest that the costs would be substantial.

6.3. Market Impacts

In 2011 the value of production of hogs and pigs exceeded $20 billion, (NASS), and the value of pork exports exceeded $ 6 billion, (ERS) . Potential market impacts of a CSF outbreak include export losses as a result of trade restrictions, reductions in consumer demand, falling retail prices for commodities, and potential alterations to industry structure due to market disruptions [ 74

, 76 ] . The impact of a foreign animal disease outbreak on the viability of rural and regional economies, including businesses reliant on livestock revenue, could also be substantial. The exten t of market impacts will depend on a number of factors, including outbreak size, the industry segments affected, the efficacy of control measures, and the reaction of trading partners. Regardless, CSF spreads rapidly, and its identification in previously free regions generally results in trade bans, so the market impacts of an outbreak are likely to be substantial.

Paarlberg et al. (2009) used an economic simulation model that captures vertical and horizontal linkages in the agricultural sector to estima te the effect that an outbreak of CSF would have on the swine industry in the United States. The duration and extent of the outbreak were extrapolated from the 1997

- 1998 Dutch CSF epidemic . Assumptions included destruction of 11 million hogs, closing of export markets with eventual full recovery, and a 1% decline in domestic demand for pork. The model evaluated two different scenarios affecting different sectors of the industry (breeding swine versus

60Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

market hogs) and the ultimate market impacts of each. Pork industry losses in returns were estimated at $4 billion over 20 quarters. Total losses for hogs, including the value of animals depopulated, was estimated at between $2.6 billion and $4.1 billion [ 76 ]

.

Garner et al (2001) estimated the potential econo mic impact of CSF introduction into two important swine producing regions in Australia. The model estimated a loss of gross

income of 28

- 37% for the pig industry in the affected regions, and a 9

- 11% loss in gross income for the national pig industry [ 77 ]

.

In conclusion, the market impacts of a CSF outbreak will vary based on the extent of the

outbreak and the reaction of domestic markets and trading partners. However, losses, particularly to export markets, are likely to be substantial.

6.4. Effects on public health

Although public health consequences are not issues under APHIS’ regulatory authority, the subject is br iefly addressed in this assessment. Direct public health consequences are insubstantial because the occurrence of CSF infection in humans is quite rare. In fact, the number of cases reported is so small when compared with the number of persons exposed

to these viruses that the World Health Organization does not consider CSF to be a

zoonotic threat to humans [ 78 ]

.

A substantial foreign animal disease outbreak can result in severe psychosocial effects on farmers and farming communities. The impact of foreign animal diseases on mental

health is best documented for foot and mouth disease, but would likely be similar following a large outbreak of any foreign animal disease. Effects such as grief over losing animals, feelings of isolation and loss of control, fear of new outbreaks, disruptions in community life, loss of trust in au thority, short

- and long

- term financial stress, and symptoms of depression and post

- traumatic stress disorder have been

documented [ 79

- 82 ] . Animal health emergency responders may also experience stress reactions and distress as a result of participating in or witnessing the culling of animals or having to deal with distraught owners of the animals [ 83 ]

.

6.5. Effects on the environment

Environmental effects have been considered under all appl icable environmental review laws in force in the United States. These are considered in a separate, but related, environmental assessment. The environmental assessment complies with the National Environmental Policy Act (NEPA) and implementing regulations [ 84 ]

.

6.6. Conclusions

The biological and economic consequences of introduc ing CSF virus into the United

States could be substantial, although they would likely vary based on the extent of the outbreak at the time of detection, the virus serotype introduced, and movement and

61Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

demographics of affected swine. Additionally, restrictions imposed by international trading partners could cause severe economic losses to the U.S. livestock industry.

62Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________



## Section 7. Risk Estimation

Risk estimation consists of integrating the results from the release assessment, exposu re assessment, and consequence assessment to produce overall measures of risk associated with the hazards identified at the outset. Thus, risk estimation takes into account the whole risk pathway from hazard identification to the unwanted event [ 2 ]

.

APHIS identified risk factors associated with importing Mexican

- origin pork and pork products into the United States from a CSF

- low

- risk region in Mexi co and proposed mitigations to address these factors. APHIS considers that with mitigations this risk from

the CSF

- low

- risk region in Mexico would be low. The CSF

- low

- risk region in Mexico recognized by APHIS includes all of Mexico except the 9

- states cu rrently recognized as

CSF

- free and the State of Chiapas for which APHIS considers the CSF risk to be unacceptable.

APHIS concludes from the exposure assessment susceptible swine in the United States are unlikely to be exposed to CSF virus via waste feeding.

Conversely, APHIS concludes that the biological and economic consequences of a CSF

outbreak in the United States could be substantial

, although they would likely vary based on the extent of the outbreak at the time of detection, the virus serotype introduced, and movement and demographics of affected swine

. C ontrol and eradication measures c ould be costly , and restrictions imposed by international trading partner s could be expected to

result cause severe economic losses to the U.S. livesto ck industry.

In summary, although the consequences of a CSF outbreak in the United States would be

serious

, based on the findings of the release and exposure assessments APHIS believes our proposed mitigations will significantly lower the risk of CSF

- infe cted pork or pork products entering the United States from a CSF

- low

- risk region in Mexico and exposing

U.S. swine to the disease.

63Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________________________________________________



## References

1. SARGARPA, S.d.A., Ganaderia, Desarrollo Rural, Pesca y Alimentacion, Submissi on doc umentation supporting request for recognition provided to APHIS in November 2007.

2. World Organization for Animal Health (OIE), Chapter 2.1 Import Risk Analysis , in Terrestrial

Animal Health Code 2012: Available online at: http://www.oie.int/index.php?id=169&L=0&htmfile=chapitre_1.2.1.htm.

3. Pathogenesis of chronic hog cholera: host response. Mengeling WL, Packer RA. Am J Vet Res. (1969) 30:409

- 17.

4. Influence of breed

- related factors on the course of classical swine fever virus infection. Depner KR, Hinrichs U, Bickhardt K, Greiser

- Wilke I, Pohlenz J, Moennig V, Liess B. Vet. Rec. (1997)

140:506

- 507.

5. Diagnostic methods for detection of classical swine fever virus

— Status quo and new developments. Greiser

- Wilke I, Blome S , Moennig V. Vaccine (2007) 25:5524

- 5530.

6. Early pathogenesis of classical swine fever virus (CSFV) strains in Danish pigs. Lohse L, Nielse n
J , Uttenthal A. Vet. Micr. (2012) 159:327

- 336.

7. Analysis of clinical samples for early detection of classical s wine fever during infection with low, moderate, and highly virulent strains in relation to the onset of clinical signs. Donahue BC, Petrowski HM, Melkonian K, Ward GB, Mayr GA, Metwally S. J. Virol. Meth. (2012) 179:108

- 115.

8. Characterisation of experim ental infections of domestic pigs with genotype 2.1 and 3.3 isolates of classical swine fever virus. Everett H, Salguero FJ, Graham SP, Haines F, Johns H, Clifford D, Nunez A, La Rocca SA, Parchariyanon S, Steinbach F, Drew T, Crooke H. Vet. Micr. (2010)

142:26

- 33.

9. Federal_Register, Classical Swine Fever Status of Mexican States of Baja California, Baj a C

alifornia Sur, Chihuahua, and Sinoloa; Final Rule. Federal Register, August 12, 2003. 68(155): p. 47835

- 47842. 2003.

10. Federal_Register, Classical Swine Fever Status of Mexican States of Campeche, Quintana Roo, Sonora, and Yucatan; Final Rule. Federal Register, March 28, 2005. 70(58): p. 15563

- 15570.

2005.

11. Federal_Register, Classical Swine Fever Status of the Mexican State of Nayarit; Final R ule. Federal Register, 2007. 72 (105): p. 30468

- 70.

12. CFR, Rinderpest, foot

- and

- mouth disease, fowl pest (fowl plague), Exotic Newcastle disease, African swine fever, classical swine fever, and bovine spongiform encephalopathy: Prohibite d

and r estricted importations. In Title 9, Code of Federal Regulations, Part 94. Animal and Plant Health Inspection Service. 2006.

13. Wengler, G., Bradley, D. W., et al. Flaviviridae . in 6th Report of the International Committee on
T

axomonmy of viruses . 1995.

14. Moennig, V., Introduction to classical swine fever: virus, disease and control policy. Ve t

M icrobiol, 2000. 73 (2

- 3): p. 93

- 102.

15. Spickler, A.R. and J. Roth, A., eds. Emerging and Exotic Diseases of Animals . 3rd Edition ed. 2006, Iow State University Pre ss. 16. Biagetti, M., Greiser

- Wilke, I., et al, Molecular epidemiology of classical swine fever in Italy. Ve t

M icrobiol, 2001. 83 (3): p. 205

- 215.

17. Laddomada, A., Patta, C. et al, Epidemiology of classical swine fever in Sardinia: a serological survey of wild boar and comparison with African swine fever. Vet Rec., 1994. 134 (8): p. 183

- 187.

18. World Organization for Animal Health (OIE). Classical swine fever technical disease card . 2009; Available from: http://www.oie.int/en/our

- scientific

- expertise/speci fic

- information

- and

recommendations/technical

- disease

- cards/.

19. Elber, A.R., Stegeman, A., et al, The classical swine fever epidemic 1997

- 1998 in The Netherlands: descriptive epidemiology. Prev Vet Med, 1999. 42 (3

- 4): p. 157

- 184.

20. Moennig, V., Floegel

- Niesmann, G., et al, Clinical signs and epidemiology of classical swine fever: a review of new knowledge. Vet Journal, 2003. 165 : p. 11

- 210.

64Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

21. Paton, D.J. and I. Greiser

- Wilke, Classical swine fever

- an update. Res Vet Sci, 2003. 75 (3): p.

169

- 178.

22. W ood, L., Brockman, S., et al, Classical swine fever: virulence and tissue distribution of a 1986 isolate in pigs. Vet Record, 1988. 122 : p. 391

- 394.

23. Edwards, S., Survival and inactivation of classical swine fever virus. Vet Microbiology, 2000.

73 (2

- 3): p. 175

- 181.

24. Fritzemeier, J., Teuffert, J., et al, Epidemiology of classical swine fever in Germany in the 1990's. Vet Microbiology, 2000. 77 (1

- 2): p. 29

- 41.

25. Dahle, J.a.L., B., A review of classical swine fever infections in pigs: epizootiology, cl inical disease and pathology. Comp Immun Micro, 1992. 20 : p. 261

- 274.

26. Elbers, A.R., Stegeman, J.A., et al, Factors associated with the introduction of classical swine fever virus into pig herds in the central area of the 1997

- 1998 epidemic in The Nethe rlands. Vet Rec., 2001. 149 (13): p. 377

- 382.

27. European Commission, S.C. Classical swine fever in wild boar . in European Commission, 1999

. 1999. Brussels.

28. Depner, K., Bauer, T., et al, Thermal and pH stability of pestiviruses. Rev Sci Tech OIE 11, 1992: p. 885

- 893.

29. Harkness, J.W., Classical swine fever and its diagnosis: a current view. Vet Record, 1985. 116 : p. 288

- 293.

30. Williams, S., Persistance of Disease Agents in Carcasses and Animal Products , L. Scott Williams Consulting Pty, Editor 2003.

31. Merck and Company, ed. The Merck Veterinary Manual . 8th Edition ed. 1998, Merck and Company.

32. World Organization for Animal Health, Chapter 2.8.3. Classical Swine Fever , in Manual of Diagnostic Tests and Vaccines for Ter restrial Animals 2012: Available from: http://www.oie.int/fileadmin/Home/eng/Health_standards/tahm/2.08.03_CSF.pdf

. 33. CFR, Importation of animals and animal products: Procedures for requesting recognition of regions. Application for recognition of the animal health status of a region. In Title 9, Code of Federal Regulations, Part 92.2. Animal and Plant Health Inspection Service. 2006.

34. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion.

NOM

- 037

- ZOO

- 1995, Nation al Classical Swine Fever Campaign, English translation provided by
SARGARPA, 2005.

35. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion.

NOM

- 054

- ZOO

- 1996, Quarantine Procedures for Animal and Animal Products, English translation provided by SARGARPA, March 2006.

36. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Official SARGARA submission received November 2007.

37. SARGARPA, Secretaria de Agricultura, Ganaderia , Desarrollo Rural, Pesca y Alimentacion

. Official SARGARA submission received March 2008.

38. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Presentation provided by SARGARA officials to APHIS during site visit to the Central Western Region, Mexico, May 2008.

39. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Official SARGARA submission received October 2009.

40. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarroll o Rural, Pesca y Alimentacion

. Official SARGARA submission received November 2009.

41. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Official letter No. B00.02.1010 regarding findings, follow up and closure of a CSF outbreak in Guerrero, Mexico, dated November 30, 2009.

42. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Official SARGARA submission received July 2010.

43. SARGARPA, Secretaria de Agricultura, Ganaderia, De sarrollo Rural, Pesca y Alimentacion

. Official SARGARA submission received August 2010.

44. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Presentation provided by SARGARA officials to APHIS during site visit to Campeche, Quintana Roo and Yucatan, Mexico, October 2010.

65Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

45. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Presentation provided by SARGARA officials to APHIS during site visit to Sonora, Mexico, January 2011.

46. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Presentation provided by SARGARA officials to APHIS during technical meeting in Mexico City, Mexico, January 2011.

47. SARGARPA, Secretaria de Agricultura, Ganade ria, Desarrollo Rural, Pesca y Alimentacion

. Presentation provided by SARGARA officials to APHIS during technical meeting in McAllen, Texas, August 2011.

48. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Present ation provided by SARGARA officials to APHIS during site visit to Mexico City and Guanajuato, Mexico, November 2011.

49. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Official SARGARA submission received February 2012.

50. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Presentation provided by SARGARA officials to APHIS during site visit to Jalisco, Mexico, February 2012.

51. SARGARPA, Secretaria de Agricultura, Ganaderi a, Desarrollo Rural, Pesca y Alimentacion

. Official SARGARA submission received April 2012.

52. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Presentation provided by SARGARA officials to APHIS during site visit to the Central Western Region, Mexico, April 2012.

53. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Official SARGARA submission received May 2012.

54. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Official SARGARA submission received August 2012.

55. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Official SAR GARA submission received September 2012.

56. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Official SARGARA submission received October 2012.

57. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Official SARGARA submission received November 2012.

58. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Presentation provided by SARGARA officials to APHIS during site visits to the States of Puebla, Mexico, Chiapas, and Veracruz, Mexico, November 2012.

59. SARGARPA, Secretaria de Agricultura, Ganaderia, Desarrollo Rural, Pesca y Alimentacion

. Official SARGARA submission received December 2012.

60. SARGARPA, Secretaria de Agricultura, Gana deria, Desarrollo Rural, Pesca y Alimentacion

. Official SARGARA submission received January 2013.

61. OIE, Office International des Epizooties (OIE), Terrestrial Animal Health Code

- 2012, Chapter

15.2. Classical Swine Fever. Available at: http://www.o ie.int/index.php?id=169&L=0&htmfile=chapitre_1.15.2.htm

. 2012.

62. CFR, Rinderpest, foot

- and

- mouth disease, fowl pest (fowl plague), Exotic Newcastle Disease, African swine fever, classical swine fever, and bovine spongiform encephalopathy: Prohibited

and restricted importations. Swine from regions where classical swine fever exists. In Title 9, Code of Federal Regulations, Part 94.10. Animal and Plant Health Inspection Service. 2006.

63. CFR, Rinderpest, foot

- and

- mouth disease, fowl pest (fowl plague) , Exotic Newcastle Disease, African swine fever, classical swine fever, and bovine spongiform encephalopathy: Prohibited and restricted importations. Pork and pork products from regions where classical swine fever exists. In Title 9, Code of Federal Re gulations, Part 94.9. Animal and Plant Health Inspection

Service. 2006.

64. APHIS, APHIS Evaluation of Classical Swine Fever Status of Sinaloa, Mexico, 2001. United States Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary

Services. 2001.

65. Health, W.O.f.A. OIE World Animal Health Information Database (WAHID) . 2012; Available from: http://web.oie.int/wahis/public.php?page=home.

66Evaluation of the CSF Status of a Region in Mexico October 2013

______________________________________________________ ________ ________________________________

66. APHIS, Pathway assessment of foot

- and

- mouth disease (FMD) risk to the United States: an evaluation in response to international FMD outbreaks in 2001, (2001). U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Center for Epidemiology and Animal Health. 2001.

67. APHIS, Risk Assessment of the Prac tice of Feeding Recycled Commodities to Domesticated Swine in the U.S. (1995). U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Center for Epidemiology and Animal Health. 1995.

68. APHIS, APHIS 2001 waste

- fe eder survey (unpublished data) (2002). U.S. Department of Agriculture, Animal and Plant Health Inspection Service, Veterinary Services, Center for Epidemiology and Animal Health. 2002.

69. Hennecken M., J.A.S.e.a., Transmission of classical swine fever vi rus by artificial insemination during the 1997

- 1998 epidemic in The Netherlands: a descriptive epidemiological study. Vet Q,

2000. 22 (4): p. 228

- 33.

70. Floegel, Floegel, G., A. Wehrend (2000). "Detection of classical swine fever virus in semen of infecte d boars." Vet Micro 77(1

- 2): 109

- 116. 2000.

71. Glossup, Glossup, C. E., and R. Cameron (2002). Transmission of viruses through pigs and products of pig origin. In: Trends in Emerging Viral Infections of Swine, A. Morilla, K. Y. Yoon & J. J. Zimmerman (Eds .). Ames, Iowa: Iowa State Press: 3

- 11. 2002.

72. Kleiboeker, S.B., Swine fever: classical swine fever and African swine fever. The Veterinary clinics of North America. Food animal practice, 2002. 18 (3).

73. Paarlberg, P.L., et al., Economic impacts of for eign animal disease. ERR

- 57 , 2008, United States Department of Agriculture. Economic Research Service: Washington, DC.

74. Saatkamp, H.W., P.B.M. Berentsen, and H.S. Horst, Economic aspects of the control of classical swine fever outbreaks in the European Union. Veterinary microbiology, 2000. 73 (2

- 3): p. 221

- 237.

75. Stegeman, A., et al., The 1997

- 1998 epidemic of classical swine fever in the Netherlands. Veterinary microbiology, 2000. 73 (2

- 3): p. 183

- 196.

76. Paarlberg, P.L., et al., Supply reductions, exp ort restrictions, and expectations for hog returns in a potential classical swine fever outbreak in the United States. Journal of Swine Health and Production, 2009. 17 (3): p. 155

- 162.

77. Garner, M.F., et al., The expected economic impact of selected exoti c diseases on the pig industry of Australia. Rev Sci Tech Off Int Epiz, 2001. 20 (3): p. 671

- 685.

78. WHO. World Health Organization

- Global Early Warning System for Major Animal Diseases, including Zoonoses (GLEWS) . Available from: http://www.who.int/zoon oses/outbreaks/glews/en/index2.html.

79. Hannay, D. and R. Jones, The effects of foot

- and

- mouth on the health of those involved in farming and tourism in Dumfries and Galloway. European Journal of General Practice, 2002. 8 (3): p. 83

- 89.

80. Mort, M., et al

., Psychosocial effects of the 2001 UK foot and mouth disease epidemic in a rural population: qualitative diary based study. BMJ, 2005. 331 (7527): p. 1234.

81. Van Haaften, E.H., M. Olff, and P.H. Kersten, The psychological impact of the Foot and Mouth Disease crisis on Dutch dairy farmers. Njas

- Wageningen Journal of Life Sciences, 2004. 51 (4): p.

339

- 349.

82. Olff, M., et al., Impact of a foot and mouth disease crisis on post

- traumatic stress symptoms in farmers. The British Journal of Psychiatry, 2005. 186 (2): p. 165.

83. Jenner, M., The psychological impact of responding to agricultural emergencies. Australian Journal of Emergency Management, The, 2007. 22 (2): p. 25.

84. National Environmental Policy Act (NEPA). 1969 [cited 2012 May 15]; Available fro m: http://ceq.hss.doe.gov/.

67

## Appendices

Appendix 1: Certification of th e Centro de Palo Alto Laborat ory as CSF Diagnostic Reference Laboratory in Mexico, November 28- December 1, 2011.......................................................... A-2

Appendix 2: SENASICA Organization Chart ......,,,.............................................................. A-8

Appendix 3: Mexico CSF Case Definition...........,,,..............................................................A-10

Appendix 4: Mexico CSF Site Visit Report: Fiel d Investigations of CSF Suspect Farms in the State of Guanajuato, November 14-18, 2011...........,,,............................................................. A-18

# Appendix 1:

Certification of the Centro de Palo Alto Laboratory as CSF Diagnostic Reference Laboratory in Mexico,

November 28

- December 1, 2011**Site Visit Report: Certification of the C entro de**  **P alo**  **A lto**  **Laboratory as CSF Diagnostic**
**Reference Laboratory in Mexico** 

**November 28 -**  **December 1**  **, 2011**

**I. Introduction** 

a. This report summarizes the findings identified by USDA

- FADDL representatives (Consuelo Carrillo and Fernando J Torres

- Velez) during the audit of the Centro de Palo Alto (CPA) reference laboratory in Mexico City and the site visits of El Salto and Zaplotane jo re gional laboratories. This audit and site visits were conducted in response to the agreed plan during the bilateral technical meeting in McAllen, Texas i n August

2011.

**II. Objectives** 

a. Audit of Centro de Palo Alto (CPA) laboratory. The following criteria were taken into consideration during the audit :
i. F acilities

1. Adequacy of equipment to performed CSF diagnostic assays

. 2. Proper allocation and separation of space per diagnostic technique ; serology, molecular (PCR), and virus isolation.

ii. Staffing

1. Suitable technical staff to perform assays

. 2. Suitable highly skill ed/trained technical staff to evaluate and interpret

results

. iii. Quality control and assurance

1. Evidence of ongoing QC/QA program supported by internal and external (international) proficiency panels.

iv. Te sting and accessions management

1. Performance of CSF screening and confirmatory assays.

2. Management (prioritization) of samples as: routine diagnostics,

s urveillanc e, and inconclusive (suspects).

3. Record keeping: traceability and consistency.

b. Re

- testing of samples collected by USDA APHIS staff (Pyburn and Gauthier) during a previous field visit.

c. Visual inspection and case management discussion of the Itxahluaca seropositive sow (ID# 290) and her piglets (CENASA).

d. Re

- evaluation of inconclusive cases [rRT PCR (+) / Conventional PCR (

- )] from Guanajuato.

e. Visual inspection (not certification) of El Salto and Zaplotanejo regional laboratorie s and audit of records in Zaplotanejo (traceability & consistency)

.

**III. Logistics** 

a. Consuelo Carrillo and Fernando J Torres

- Velez conducted the audit and site visits. During the week

- long visit, Carrillo was based in the CPA laboratory where she audited electronic and hardcopy records, and the techniques of the diagnostic assays . In

addition she oversaw the testing of samples previously collected by APHIS F ADD staff (Pyburn and Gauthier) . Torres

- Velez supported Carrillo and traveled to El Salto andZaplotanejo regional laboratories to conduct visual inspections of the facilities and

audits of records for traceability in Zaplotanejo (followed paper trail of inconclusive cases submitted to CPA)

. A closing meeting to discuss findings, corrective measures, and future support was held at CENASA laboratories and hosted by the director Dr. Joaquin Delgadillo. This laborator y also housed sow #290.

**IV. Findings (per objectives**  **as listed in section II**  **)**

a. Audit

i. Facilities: adequate

. ii. S taffing: adequate

. iii. QA/QC : adequate.

iv. Testing (assays) and accessions management : 1. Twelve cases were selected at random from CPA’s records (Table 1)

. These cases were submitted to CPA for confirmation from the regional

laboratories where these were classified based on the clinical and epidemiological history as : routine diagnostic, surveillance, or priority 1.

2. Three positive cases (inconclusive) at the Zaplotanejo regional laboratory were selected at random to assess traceability and consistency with

records in CPA’s database and record keeping logs (Table 1). N o concerns with traceability and consistency of records were found

. 3. Technical findings and suggested corrective measure are broken down per assay and summarized in Table 2.

b. Samples collected by USDA

- APHIS staff during a p revious field visit were all negative.

c. The Itxahluaca seropositive sow (ID# 290) and 5 piglets are being housed in the CENASA biocontainment facility.

i. One out of the 5 piglets is a naïve sentinel.

ii. All these animals are being sampled (oral swabs, tonsil scrapings, and serum) and tested weekly (rRT

- PCR and serology).

1. rRT

- PCR for all animals was negat ive

2. Serology: all are seropositive (except sentinel)

d. Re

- evaluation of Guanajuato cases [original result: rRT PCR (+) / Conventional PCR ( -)]

i. Original locations (case ID):

1. Ma. Elvira (19043 / 21801 / 25406)

2. Medina (19022 / 21800 / 25379)

ii. U pon further testing

, the above mentioned cases still remain inconclusive : r RT PCR (+) / Conventional PCR (+ ) using a new set of primers targeting a different region of the genome

. iii. These results are pending further analysis since the conventional PCR was a

modified protocol (redesigned primers )

. These samples are pending shipment to

Plum Island for further evaluation.

e. No irregularities were found during the visual inspection of El Salto and Zaplotanejo regional laboratories and audit of records (Zaplotanejo).

**V. Closing Meeting at CENASA laboratory;**  **December 2, 2011**

a. During the closing meeting, Drs. Pedro Paz and Joaquin Delgadillo agr e ed to house the seropositive s o w #290 and piglets for 65 days. Possible options to manage the caseafter this time frame were discussed but nothing finalized due to the cost of extended housing.

b. September 13, 2012 was established as a possible starting point for declaration of free status based on the findings of this audit.

c. FADDL offered the following support services:

i. Diagnostic assistance of any suspect/inconclusive case(s)

ii. Assistance in the production of reagents

1. Antisera

2. Tissues ( in high viremic phase for IHC controls if test is added to their repertoire )

iii. References/bibliographies (they have limited access to peer reviewed literature)

**VI. Concluding Remarks:** 

a. CPA leadership and staff were extremely accessible and transparent during this

process. b. APHIS

- FADDL recognizes the significant advances accomplished by CPA in CSF diagnosis in the time frame provided. Passing results in the international H annover CSF proficiency panel is proof of this.

c. In addition to the corrective measures suggested in Table 2, we identified a communication gap between the field and the laboratory. The following recommendations were given to assist in bridging that gap :
i. Involve the laboratory at the early stages of a field investigation: this will improve the communication between the FADD (field veterinarian) and the laboratory.

ii. Switch mode from surveillance to Priority1: once a regional laboratory makes a

s uspect / p resumed positive determination, the case should be managed as a priority 1 and no longer as a surveillance case. This will help to shorten the quarantine period.

d. FADDL is waiting for the import of inconclusive samples from Guanajuato.TABLE 1 . Cases selected at random for audit.

Records Audited Accessions (cases) audited
in CPA Accessions (cases) audited in Zaplotanejo

26003 26038 22343

26002 25222 22168

25999 25128 20720

25994 25010

- 25350

25996 16789

- 24304

25975 25531TABLE 2 Procedure / Diagnostic

T echnique Finding(s) Suggested Corrective Measure Rationale

ELISA IDEXX This assay was o nly performed at regional laboratories

. Repeat this assay at the CPA laboratory before performing confirmatory assays (IP and SNT)

. Validation of the ELISA IDEXX

results performed at the regional

laboratories is more time and cost effective than overwhelming CPA’s
SNT and IP test capacity.

Sero neutralization (SNT) Based on the Hannover proficiency panel results, CPA may be experiencing a slight decrease in sensitivity of the PK

- 15 cells currently used in this assay. Change to or add another cell line

to the a ssay, such as SK

- 6. Weak positive s may escape detection in PK

- 15 if these cells are not sensitive enough to infection.

rRT

- PCR False positives: [rRT

- PCR (Ct ≤ 40), conventional PCR and VI (

- )] are not being further investigated , but

recorded as negatives. To rule out contamination, the original sample can be retested using fresh reagents. Alternatively, the amplified RNA can be sequenced. Ct values equal or lower than 40 MUST be reported as positive, even
if the conventional nested PCR and VI are negatives. In this case of apparent false positive, a laboratory

contamination must be ruled out
first.

Inconclusives : [rRT

- PCR (Ct = 41

- 45), conventional PCR (- )] are not being further investigated, but

record ed as negatives. Run the sample RNA by rRT

- PCR again and if the result still

inconclusive a new RNA extraction must be perform and test by rRT

- PCR and by VI. Ct values 41

- 45 MUST be reported as inconclusives, even if the

conventional ne sted PCR is ( -), and
follow ed up with a confirmatory test.

. General comments:

• Retest suspect cases referred from regional laboratories before subjecting the samples to VI.

• Results of all assays performed to rule out the original result as a false positive or inconclusive must be

included in the case record.

• Impleme nting these practices in molecular diagnostics crucial as it will provide the laboratory with

valuable e xperience in the behavior of the assay ’ s reagents and conditions

. Conventional nested PCR (Sandvick technique) Extremely f aint bands in the gel

. Develop a titration curve using

various concentr ation s of the control RNA. Test these samples in parallel by rRT

- PCR. Faint bands make interpretation challenging and occasionally subjective. A titration curve will help

to assess the sensitivity of the ass ay and how it compa res to Ct values using r RT

- PCR Extraction control is not being used. Include actin as an extraction

control. An extraction control assures that negative samples are not false negative (RNA was extracted from tissues).

# Appendix 2:

SENASICA Organization ChartDIRECCIÓN GENERAL DE SALUD ANIMALNOTA:El departamentode Regulación yRegistrosactualmenteestá registrada enla DirecciónGeneral deinocuidad,Agroalimentaria,Acuícola yPesqueraMA1SUBDIRECCIÓNDE PLANEACIÓN YCONTROL SANITARIONA1DEPARTAMENTODE PLANEACIÓNOA1DEPARTAMENTODE CONTROLSANITARIODIRECCIÓNGENERAL DESALUD ANIMALKA1DIRECCIÓNDE VIGILANCIAEPIDEMIOLÓGICAMB1DIRECCIÓNDE CAMPAÑASZOOSANITARIASMB1SUBDIRECCIÓNDE REGIONALIZACIÓN,RASTREABILIDAD YANÁLISIS DE RIESGONB1DEPARTAMENTODE RASTREABILIDADOA1DEPARTAMENTODE REGIONALIZACIÓN YANÁLISIS DE RIESGOOA1SUBDIRECCIÓNDEL SISTEMA NACIONALDE VIGILANCIAEPIDEMIOLÓGICANB1DEPARTAMENTODE REGISTRO, ANÁLISISY DIFUSIÓN DEINFORMACIÓNOA1SUBDIRECCIÓNDE SANIDAD ENESPECIES MENORESNB1DEPARTAMENTODE SANIDADPORCINAOB1DEPARTAMENTODE SANIDADAVÍCOLAOA1SUBDIRECCIÓNDE SANIDAD ENESPECIES MAYORESNA1DEPARTAMENTODE TUBERCULOSISBOVINA Y BRUCELOSISOA1DEPARTAMENTODE RABIA PARALÍTICABOVINA Y GARRAPATAOA1DIRECCIÓNDE IMPORTACIÓN,EXPORTACIÓN, SERVICIOSY CERTIFICACIÓN PECUARIAMB1SUBDIRECCIÓNDE IMPORTACIONESY EXPORTACIONESNB1DEPARTAMENTODE IMPORTACIONESOB1DEPARTAMENTODE EXPORTACIONESOB1SUBDIRECCIÓNDE APROBACIÓN,CERTIFICACIÓN,REGISTROS Y SERVICIOSNB1DEPARTAMENTODE REGULACIÓN YCONTROL DE MÉDICOSVETERINARIOS, UNIDADES,LABORATORIOS YORGANISMOSOA1DEPARTAMENTODE REGULACIÓN DEESTABLECIMIENTOSOA1DEPARTAMENTODE REGULACIÓN YREGISTROS DE PRODUCTOSVETERINARIOSOB1DIRECCIÓNDE SANIDADACUÍCOLAY PESQUERAPROPUESTA DE REESTRUCTURACIÓNVIGENCIA: 1 DE ENERO DE 2008GOBIERNOFEDERAL

# Appendix 3:

Mexico CSF Case DefinitionSERVICIO NACIONAL DE SANIDAD, INOCUIDAD Y CALIDAD AGROALIMENTARIA

DIRECCIÓN GENERAL DE SALUD ANIMAL
No. DE OFICIO 800.02.01 /354 

# 1613

SECRETARÍA DE AGRICULTURA, 4AISADERÍA, DESARROLLO RURAL,

PESCA y AllmJNTACIÓN SAGARPA

"2011, Año del Turismo en México" México, D.F a 4 de abril de 2011 

### DR. JOHN R. CLIFFORD DEPUTY ADMINISTRATOR DE APHIS/USDA

Hago referencia a los compromisos acordados entre el SENASICA y el APHIS/ USDA, a fin de reevaluar la definición de caso de Fiebre Porcina Clásica (FPC), considerando las observaciones realizadas por parte de ambas dependencias durante el "Curso-Taller sobre investigación epidemiológica de fiebre porcina clásica México/Estados Unidos", que
se llevó a cabo del 19 al 21 de enero de 2011 en la ciudad de México. Con base en lo anterior, se ha modificado y adecuado la definición de FPC quedando de la siguiente

manera:


### DEFINICIÓN DE CASO DE FPC:

1. Caso Clínico.- El periodo de incubación del virus de FPC generalmente es de 7 a 10 días con un intervalo de 2 a 15 días. Bajo condiciones de campo el virus puede pasar desapercibido hasta por 24 semanas después de la introducción a la piara. La Organización Mundial de Sanidad Animal (01E) reconoce un periodo de incubación de varios meses para cerdos expuestos in-útero, mientras que los cerdos expuestos después del nacimiento tienen un periodo de incubación de 2 a 14 días.

Se considera como caso clínico a una piara con signología clínica compatible con FPC, en la cual se observan cerdos con una viremia caracterizada por fiebre persistente igual o

mayor a 41°C; constipación; decoloración de la piel; hiperemia difusa; zonas de necrosis en las orejas, en la cola y en los labios de la vulva; conjuntivitis y en algunos cerdos los párpados con exudado purulento. Con frecuencia se observan signos nerviosos como deambular en círculos, incoordinación, temblor muscular y convulsiones, aún en las fases tempranas de la enfermedad; otros signos son abortos, vómito y/o diarrea que no responden a tratamiento con antibióticos. La infección en cerdas preñadas puede producir sólo una ligera hiperemia que va seguida de un incremento de abortos, carnadas reducidas de tamaño, momificación, mortinatos y/o anomalías en las crías.

En cerdos infectados con cepas de baja y moderada patogenicidad, el diagnóstico clínico es difícil, especialmente en cerdos viejos ya que generalmente estas infecciones se manifiestan con casos leves o una infección subclínica que puede pasar desapercibida or mucho tiempo, en estos casos el periodo de incubación es más largo que el normal y

...2 Av Cuauhtémoc No 1230 Piso Si Cu: unta Cruz Atoyac, Del. Benito Juárez_ México, D.F. CP 03310 Tel. 4 52 (55) 59 05 10 00 ext. 51055 y 51092

www senasica gob mxSERVICIO NACIONAL DE SANIDAD, INOCUIDAD Y CALIDAD AGROALIMENTARIA

DIRECCIÓN GENERAL DE SALUD ANIMAL

No. DE OFICIO B00.02.01./354 

# 1613

2 SECRETARÍA DE AGRICULTURA, GANADERÍA, DESARROLLO RURAL,

PESCA V ALIMENTAC,ON SAGARPA

se pueden encontrar los siguientes signos: emaciación, alopecia, dermatitis, decoloración de las orejas y una coloración púrpura de la piel en el abdomen.

Cabe mencionar, que la leucopenia es un hallazgo consistente en laboratorio (excepto con cepas de baja virulencia) y la severidad de la enfermedad con cepas patógenas. puede ser variable y manifestarse de tres formas distintas:

Aguda.- se presenta en lechones destetados menores de 12 semanas de edad que no responden a un tratamiento con antibióticos, los cuales pueden presentar signología caracterizada por fiebre (41°C), anorexia, letargia. hiperemia multifocal y lesiones hemorrágicas de la piel, conjuntivitis, cianosis de la piel (especialmente en las extremidades, orejas, miembros, cola y hocico), disnea, tos, estreñimiento seguido por diarrea, vómitos (ocasionales), ataxia, debilidad de los miembros posteriores, paresis, convulsiones, abortos (rara vez) y/o amontonamiento de los cerdos. La muerte se produce de 5-15 días después del comienzo de la enfermedad; la mortalidad de los cerdos jóvenes puede aproximarse al 100%.

En la fase aguda. el virus de la FPC ocasiona las siguientes lesiones: leucopenia. trombocitopenia, hemorragias petequiales y equimosis con distribución difusa, especialmente en la piel, nódulos linfáticos, laringe, vejiga y válvula ileocecal, así como infarto multifocal del bazo (es característico pero no siempre se produce), es común encontrar tumefacción de ganglios linfáticos y encefalomielitis con infiltración linfocitaria perivascular.

Crónica.- los cerdos recuperados de una infección aguda, pueden desarrollar un cuadro crónico caracterizado por una infección subaguda, seguida por una convalecencia breve y una recaída con fiebre, anorexia, dermatitis, postración, apetito irregular, pirexia, diarrea (puede durar hasta un mes) e incremento de redrojos en la piara. La muerte ocurre de 1 a 3 meses después del cuadro inicial.

En esta fase, se pueden encontrar las siguientes lesiones: úlceras en forma de botón en el ciego y el intestino grueso, así como depleción generalizada del tejido

linfoide.

c) Congénita- se presenta en lechones que nacen de madres infectadas después del día 50 a 70 de la gestación, los cuales pueden estar infectados y no manifestar signos clínicos por varios meses antes de morir, o pueden nacer con tremores congénitos. Las hembras que se infectan antes del día 50-70 de gestación pueden
.3 Av. Cuauhtemoc No 1230 Piso 9 Col. Santa Cruz Atoyac. Del Benito Juarez México, D.F. CP 03310

Tel

. +52 (55) 59 05 10 00 ext. 51055 y 51092 w" senasica.gob mxSERVICIO NACIONAL DE SANIDAD, INOCUIDAD Y CALIDAD AGROALIMENTARIA

DIRECCIÓN GENERAL DE SALUD ANIMAL

No. DE OFICIO B00.02.01./354 

# 1 6 1 3

- 3 - SECRETARÍA DE AGRICULTURA, GANADERÍA, DESARROLLO RURAL,

PISCA V AIIMENTACIÓN SAGARPA

abortar o tener lechones muertos, momificados o lechones vivos con defectos congénitos o débiles. El único indicativo de una infección congénita por FPC, puede ser la disminución de los índices reproductivos de la piara por abortos,
mortinatos o lechones débiles.

Las principales lesiones que se pueden encontrar son: dismielogenia central, hipoplasia cerebelar, microencefalia, hipoplasia pulmonar, hidropesía y otras
malformaciones.

Es importante destacar, que también se pueden considerar como caso clínico aquella piara con signología y lesiones compatibles con FPC en los que existe evidencia de importación de material genético; o se utiliza escamocha como alimento; o se identifica una relación epidemiológica de personas relacionadas con la producción porcina en otro país.

Caso sospechoso de FPC.- Es aquel que corresponde a la definición de caso clínico; o aquel caso con resultados positivos a ELISA, inmunoperoxidasa y virus seroneutralización, sin información epidemiológica ni signos clínicos compatibles con la enfermedad: o aquel caso en el cual el resultado del PCR convencional/ tiempo real no es concluyente y/o la secuenciación del virus está pendiente en una muestra tomada durante la vigilancia epidemiológica activa o pasiva.

Caso presuntivo positivo de FPC.- Corresponde a un caso sospechoso con resultado positivo repetido a RT-PCR convencional/tiempo real o con secuenciación genómica posterior a RT-PCR convencional de una muestra de cerdos con o sin signos clínicos y/o evidencia epidemiológica de la enfermedad: o un cerdo o piara con información epidemiológica y/o signologia clínica compatible con la enfermedad y RT-PCR convencional/tiempo real positivo; o una prueba de inmunohistoquímica positiva; o una prueba de seroneutralización positiva.

4. Caso confirmado de FPC.- es un porcino en el cual se aísla el virus de la FPC, con o sin aparentes signos clínicos, lesiones compatibles y/o evidencia epidemiológica; y el virus es confirmado por secuenciación en el laboratorio de la CPA.

TIPOS DE MUESTRAS Y TÉCNICAS DIAGNÓSTICAS PARA LA IDENTIFICACIÓN

DEL VIRUS DE FPC.- deberán obtenerse y enviarse en refrigeración a un laboratorio oficial las siguientes muestras tomadas de cerdos clínicamente enfermos: tonsilas, hígado

...4
Av. Cuauhtémoc No 1230 Piso 9 Col Santa Cruz Atoyac. Dei Benito Juárez. México, D.F. CP 03310 Tel +52 (55) 59 05 10 00 ext. 51055 y 51092

www.senasica.gob.mxSAGARPA
SENASICA

31RECCION GENERAL DE SALUD AMMAt

'94°3*4'4 SERVICIO NACIONAL DE SANIDAD, INOCUIDAD Y CALIDAD AGROALIMENTARIA DIRECCIÓN GENERAL DE SALUD ANIMAL

No. DE OFICIO B00.02.01./354 

# 1613

-4- SECRETARIA DE AGRICULTURA, GANACIERIA, DESARROLLO RURAL,

PESCA Y ALIMENTACIÓN SAGARPA

riñón, nódulo linfático e íleon distal y las muestras de sangre completa conservada con anticoagulante (heparina o EDTA).

Los métodos de diagnóstico que se desarrollarán en las muestras de tejidos serán: inmunohistoquímica utilizando anticuerpos monoclonales específicos; PCR convencional y tiempo real; aislamiento viral seguido de inmunohistoquímica y/o PCR convencional o tiempo real y análisis de secuencia. En suero sanguíneo se realizará la detección de anticuerpos para FPC por la técnica de ELISA la cual será confirmada por inmunoperoxidasa y virus seroneutralización. corroborado con PCR, aislamiento viral y

secuenciación. 

### DIAGNÓSTICO DIFERENCIAL.- fiebre porcina africana: enfermedad de Aujeszky; síndrome reproductivo y respiratorio porcino (PRRS), parvovirosis; circovirus porcino; enfermedad de la frontera; síndrome de dermatitis y neuropatía porcina; síndrome multisistémico de desgastamiento post-destete; diarrea viral bovina; púrpura trombocitopénica, condiciones septicémicas por salmonelosis, erisipelosis, pasteurelosis, actinobacilosis. hemofilosis por H. parasuis, estreptococosis: abortos por secuelas de la enfermedad de Aujeszky, encefalomielocarditis o síndrome reproductivo y respiratorio porcino (PRRS), así como algunas intoxicaciones y mortinatos.

EL 

### DIRE 

## TOR GENERAL 'l'II 

## ATENTAMENTE ..11(.,54,43,A4Indejsk.

i Difti fYIRAL DE SALUD ANIMAL


## 1 r 1 

# 4 AB 2011 U (-- b L-------------i- -- 1 

# EznImi
ffl rn,

, 

### n

- ' 

## OSO SANCHEZ

" 

## ''

. OFICIALIA DE
PARTES 

## MVZ. HUG

Ccp MVZ. ENRIQUE SANCHEZ CRUZ.- Director en Jefe del SENASICA. DR. CONRAD ESTRADA.- Veterinary Attaché de APHIS/ USDA. DR. ASSAD HENEIDI ZECKUA.- Director de Epiderniologia y Análisis de Riesgo.

MVZ. IGOR ROMERO SOSA.- Director de la CPA.

Av Cuauhtémoc No 1230 Piso 9 Col Santa Ciuz Atoyac. Del Benito Juárez México. D.F. CP 03310

Tel. 4 52 (55) 59 05 10 00 ext. 51055 y 51092 wv.m.senasica gob mxCourtesy Translation

Letter No. B00.02.01/354 1613

Mexico City, Mexico, 4 April 2011

DR. JOHN R. CLIFFORD

DEPUTY ADMINISTRATOR

APHIS/USDA

Reference is made to the commitments agreed between SENASICA and APHIS/USDA

in order to evaluate the Classica l Swine Fever (CSF) case definition, considering the comments made by both offices during the Mexico/US CSF Epidemiological Investigation Workshop held from 19 to 21 January 2011 in Mexico City. Based on the above, the CSF definition has been modified as follows:

CSF CASE DEFINITION

1. Clinical Case – The CSF virus incubation period is generally 7-10 days with an interval of 2-15 days. On field conditions the virus could be unnoticed up to 24 weeks after its introduction to the herd. The World Organizatio n for Animal Health (OIE) recognized an incubation period of several months for exposed pigs in

- utero , while the pigs exposed after birth have an incubation period of 2-24 days.

It is considered as a clinical case, a herd with clinical signs compatible to CSF, where pigs are observed with signs characterized by persistent fever equal or higher than 41 o C; constipation; decolorizing of the skin; diffused hyperemia; necrosis in ears, tail and the vulva lips; conjunctivitis and in some pigs the eyelids have purulent exudate. Neurological signs are frequently observed such as wandering in circles, lack of coordination, muscle trem ors and convulsions, even in the early phases of the disease; other signs are abortion, vomit and/or diarrhea not responding to treatm ent with antibiotics. The infection in pregnant female pigs can cause a light hyperemia followed by the increasing of abortions, litters reduced in size, mummification, birth of dead pigs

and/or other defects in the litters.

In pigs infected with low and moderate virulence strains, the clinical diagnosis is difficult, especially in old pigs, since these infections are shown as mild cases or a subclinical infection that can be unnoticed for a long time, in this cases the incubation period is longer and the following signs can be found: emaciation, alopecia, dermatitis, decolorizing of ears and purple coloring of the abdomen skin.It is worth to mention that leucopenia is a consistent finding in laboratory (except with low virulence strains) and the severity of the disease with high virulence strains can vary and show in three different ways:

a) Ac ute - Weaned suckling pigs less than 12-weeks old not responding to an antibiotic treatment, which can present signs characterized by fever ( 41 o C)

, anorexia, leth argics, multifocal hyperemia, and hemorrhagic lesions in the skin, conjunctivitis, cyanosis in the skin (especially in the extremities, ears, penis, tail and mouth), dyspnea, cough, constipation followed by diarrhea, vomit (occasionally), ataxia, weakness in rear legs, paresis, convulsions, abortions (infrequently) and/or piling of the pigs. Dead happens 5- 15 days after sickness started; mortality in young pigs can be near 100%.

In the acute phase, the CSF virus causes the following lesions: leucopenia, thrombocytopenia, petechial hemorr hage and ecchymosis with diffuse distribution, especially in the skin, lymphatic nodes, larynx, bladder and ileocaecal valve, as well as multifocal infarct to the spleen (it is characteristic but it does not always happen), it is common to find swelling of lymphatic ganglia and encephalomyelitis with perivascular lymphocytic infiltration.

b) Chronic – The pigs recovered from an acute infection can develop a chronic chart characterized by a subdued acute infection, followed by a short convalescence and a relapse with fever, anorexia, dermatitis, prostration, irregular appetite, pyrexia, diarrhea (lasting up to one month) and increasing of runts in the herd. Dead happens 1-3 months

after the first chart.

In this phase, the following lesions can be found: ulcers like buttons in the blind gut and the large intestine, as well as general depletion of the lymphatic tissue.

c) Congenital infection – pigs born from infected mothers after day 50 to 70 of gestation, which can be infected without showing clinical signs for several months before dying, or they are born with congenital tremors. The females infected before

the 50-70 th day of gestation may abort or give birth to dead or mummified pigs, or live pigs with congenital defects or weak . The only indication of a congenital infection by CSF could be the lowering of reproduction indexes in the herd due to abortion, pigs born dead or weak.

The main lesions that can be found are: central dismyelogenous, cerebell um hypoplasia, microencephalia, lung hypoplasia, hydropsy and other malformations.

It is worth to mention that a clinical case can be also a herd with signs and lesions compatible to CSF where there is evidence of genetic material importation; or garb age is used for feeding; or it is identified an epidemiological relationship with people related with swine production in other country.

2. CSF Suspected Case – A case corresponding to the definition of clinical case; or such case with positive results t o ELISA, immunoperoxidase and seroneutralization virus, without epidemiological information nor clinical signs compatible with the disease; osuch case where the results of conventional/rt-PCR are not conclusive and/or the virus sequencing is pending in a sample taken during active or passive epidemiological

surveillance.

3. CSF Presumptive Positive Case – Corresponding with a suspected case with repeated positive results to conventional/real time RT -PCR or with genomic sequencing after a

conventional RT-P CR of a swine sample with or without clinical signs and/or epidemiological evidence of the disease; or a pig or herd with epidemiological information and/or clinical signs compatible with the disease and positive

conventional/real time RT

- PCR; or a positive immunohistochemical test; or a positive

seroneutralization test.

4. CSF Confirmed Case – A pig on which the CSF virus is isolated, with or without clinical signs, compatible lesions and/or epidemiological evidence; and the virus is confirmed by sequenci ng in the CPA laboratory.

SAMPLE TYPES AND DIAGNOSIS TECHNIQUES FOR CSF VIRUS

IDENTIFICATION

– The following samples from clinically sick pigs must be taken and sent in refrigeration to an official laboratory: tonsils, liver, kidney, lymphatic nodes and distal ileum, and the whole blood samples must be preserved with anticoagulant (heparin or EDTA).

The diagnosis methods to be developed in the tissue samples will be: immunohistochemical using specific monoclonal antibodies; conventional and real time PCR; virus isolation followed by immonohistochemical and/or conventional or real time PCR and sequencing analysis. In the blood serum, antibodies detection for CSF will be carried out by ELISA, which will be confirmed by immunoperoxidase and virus

seroneutrali zation, confirmed with PCR, virus isolation and sequencing.

DIFFERENCIAL DIAGNOSIS

– African swine fever; Aujeszky ’s disease; porcine reproductive and respiratory syndrome (PRRS), parvovirus disease ; porcine circovirus; border disease; porcine dermatitis and neuropathy syndrome; port- weaning weakness multisystemic syndrome; bovine viral diarrhea; thrombocytopenic purple; septicemic conditions for salmonellosis, erysipela, pasteurellosis, actinibacillosis, hemophillosis by H. parasuis , streptococcus, abortions due to Aujeszky’s disease, encephalomyelicarditis or porcine reproductive and respiratory syndrome (PRRS), as well as some intoxications and pigs born dead.

SINCERELY,

THE GENERAL DIRECTOR

DR. HUGO FRAGOSO SANCHEZ

# Appendix 4:

Mexico CSF Site Visit Report: Field Investigations of CSF Sus pect Farms in the State of Guanajuato,

November 14

- 18, 2011

# Mexico CSF Site Visit Report

Field Investigations of CSF Suspect Farms in the State of Guanajuato

Monday, 14 Nov 2011 to Friday, 18 Nov 2011

**Participants**

APHIS: Conrad Estrada and Marta Chavez (IS); Dave Pyburn and Julie Gauthier (VS)

SENASICA: Hugo Fragoso, Assad Heneide, Igor Romero, CPA staff

Guanajuato animal health Comit é staff

Sheesley Enterprises: Dan Sheesley and Juan Carlos Valladares



### Schedule

Mon, 14 Nov 2011 AM

– D. Pyburn and J. Gauthier t ravel to Mexico City

PM – M eet ing at Nikko Hotel with APHIS, SENASICA

, and Sheesley Ent erprises representatives to plan activities

Tues, 15 Nov 2011 AM

- Travel to Ira puato, Guanajauto

PM – Meeting at Farmer’s Union to in terview two producers individually :

• J. Guadalupe Medina Martinez, owner of Medina Farm in Abasolo,
Guanajuato

• Salvador Reyes Rodriguez, owner of Maria Elvira II in Penjamo,
Guanajuato
Wed, 16 Nov 2011 • D. Pyburn and C. Estrada collect samples at Maria Elvira II farm,
Penjamo

• M. Chavez and J. Gauthier collect samples at Medina farm, Abasolo
Thurs, 17 Nov 2011 AM

– Travel from Guanajuato to Mexico City

PM – Debriefing at the Sheraton with APHI S, SENASICA, and Sheesley
Enterprises r epresentative s Fri, 18 Nov 2011 D. Pyburn and J. Gauthier return to the U.S. from Mexico City



### Medina farm, Abasolo, State of Guanajuato

**Epidemiologic Investigation**

The Medina swine herd was tested as part of the CSF active surveillance program on 19 Sep 2011. Thirty

five serum and seven whole blood samples were collected. The serum from one sow (#257) gave apositive result on a CSF ELISA test performed at the CPA central laboratory. Confirmatory serologic test

results were reported by CPA on 8 Oct 2011; t he im munoperoxidase (IP) test result for serum from s ow

#257 was suspect and the seroneutralization (SN) test result was positi ve for CSF at a titer of 1:80.

Due to the positive serologic test results, SENASICA issued a quarantine which was communicated with

t he owner on 13 Oct 2011 . Resampling of the herd also took place on 13 Oct 2011 ; whole blood and

serum was collected from 60 animals

. Again, serum from sow #257 was positive by ELISA and suspect by

IP. Another sow (#301) also tested positive by ELISA, but n egative by IP. Negative virus isolation and CSF

real

- tim e polymerase chain reaction ( PCR ) test results were repo rted by CPA on 20 Oct 2011. However,

the real

- time PCR test worksheets provided to APHIS by CPA s how 25 positive test results for whole

blood samples taken during the resampling on 13 Oct 2011. Results for the positive and negative

controls run with the real

- time PCR tests suggest that the tests were valid.

Medina farm

, owned by Señor J. Guadalupe Medina Martinez, located in Abasolo, Guanajuato has

existed for more than fifteen years. The farm raises swine from farrow to finish confined in a concrete

building. The swine do not have access to the outdoors, and entry of people and animals is restricted by

a solid gate and a high brick wall surround ing the premises. Manure is scraped from the solid concrete

pen floors, carted to the street in a wheelbarrow, and loaded onto a vehicle to be carried and spread on

local fields. Within the compound, the farm also has 14 cows for milk production, two sheep , and several

caged pigeons. The producer ’ s home is within the farm compound.

The producer reported his inventory of swine as 43 sows, 5 boars, 60 unweaned piglets, and approx. 150

fattening pigs. All replacement gilts are born on the farm. Replacement bo ars are purchased at an auction in Abasolo, where boars are brought in from several areas of Mexico. Three boars were

purchased in 2011, all fro m the Abasolo auction. Two boars purchased in September originated in

Chiapas, and one boar purchased in January originated in Jalisco , according to the owner

.

He does not feed waste food to the pigs, other than whey byp roduct from cheese

- making using milk

from hi s own cows. The swine diet is based on sorghum, which is grown locally. The nursery pigs are fed

a comm ercial diet.

Sr. Medina reported that he did not notice any illness in the swine this year, other than diarrhea in 15

day

- old piglets last May, and one growing pig with bloody diarrhea a month ago. He believes that the

diarrhea can be attributed to weathe r and diet change.

Sr. Medina employs one person to help on the farm. Visitors do not routinely enter the farm. The

producer keeps a foot bath at the entrance to the barn and at the exit from the barn to his home.

Fattening pigs are moved from the nursery area into the finishing area in group s of 20

- 25 pigs, and they

remain in those groups until finished. A buyer comes to the farm with a truck to pick up finished pigs

and deliver them to the municipal slaughter house.

There are four other swine farms with in 200

- 500m of Medina farm. Two farms were tested during active

surveillance in May, apparently with negative results, and two farms were tested as part of the perifocalinvestigation in September and October, which also were reported by SENASICA personnel to have

negative ELISA test results.

Sr. Medina suspects that a CSF seropositive sow ( ear tag # 257) might have been vaccinated for CSF at

some time in her life , because she is an old sow, possibly 5

- 6 years old. However, b oth the producer and

the CPA per sonnel reported that CSF vaccination ceased in th at region in May, 2004.

Medina farm remains under quarantine pending test results on recent samples taken by CPA on 10 Nov,

2011. The producer has approximately 20 finished hogs that need to be marketed at t his time.

The producer was reluctant for us to re

- bleed animals that had been sampled only a week ago, so we

discussed a plan of collecting tonsil scrapings and nasal swabs from younger animals (10

- 14 weeks old).

The producer also agreed to allow us to sa crifice a ny ill pigs for necropsy. Guanajuato Comit é

representatives offered to purchase sick pigs for necropsy.



### On

**- farm investigation** 

Investigators: Iram Gonzalez (CPA), Jesus Arellano (Comit é ), Marta Chavez and Julie Gauthier (APHIS)

We arrived at the farm at approximately 10:00am. We established a ‘clean

- dirty ’ line at the farm gate,

organized our equipment, and donned PPE. First, we walked through the entire facility to visually inspect

the animals and map the premises. We did not observe clinical signs of illness suggestive of CSF,

although there were several lame pigs of various ages, and many with dermatitis, possibly sarcoptic

mange. Sow #257 was present and appeared healthy. One runt ( ‘ redrojo ’ in Spanish ) – a thin, unthrifty

looking growing pig
- was separated from the rest of the herd. The producer offered this pig for

euthanasia and necropsy.

We sampled 25 pigs in the 10 to 14

- week

- old range from two different pens , taking tonsil scrapings and

nasal swabs. The material from each tonsil scraping was placed in two separate conical tubes with a

small amou n t (approximately 1 ml) of PBS. Both nasal cavities were swabbed, and each swab was place

in a red top v ial with a small amount (approximately 1⁄2 ml) of PBS. Each sam pled pig was identified with

an ear tag. The yellow ear tags were labeled with consecutive numbers 1

- 24.

The runt was euthanized by electrocution and a necropsy was performed. The pig was small and thin for

its age. No gross lesions were evident on necropsy. Lymph nodes were very small and difficult to locate.

We collected serum and fresh tissues: tonsils; submandibular, axillary, gastrohepatic, and mesenteric

lymph nodes; spleen; distal ileum; heart, lung, liver, and kidney.

We cleaned and disinfected our equipment with Virkon ® and rem oved our PPE at the farm gate. Trash

was left with the producer, who said that he would burn it. Samples were bagged, the exterior of the bag

was disinfected, and the box of samples was transported to a mobile lab provided by CENASA , which was

parked near the Maria Elvira II farm in Penjamo.

In the ‘d irty’ room of the mobile lab, Marta Chavez and Julie Gauthier packaged the samples into two

groups. Each set of samples consisted of tonsil scrapings, nasal swabs, and a set of fresh tissues. One set

was labeled for CPA, and the other set was labeled “Save for Consuelo Carrillo” for her to use during theCPA central lab visit planned for 28 Nov 2011. Sample sets were placed in the refrigerator of the mobile

lab. Mobile lab personnel told us that they would drive the samples to the CPA central lab the following

morning (17 Nov 2011) . Conrad Estrada contacted Pedro Paz at the CPA central laboratory, and asked

him to save the set of samples marked for Consuelo unopened in the refrigerator.



### Maria Elvira II farm, Pen **jamo, State of Guanajuato**

**Epidemiologic investigation**

The Maria Elvira II swine herd was tested as part of the CSF active surveillance program on 19 Sep, 2011

, the same date that the Medina herd was sampled. The serum from o ne sow (#619 ), out of 35 serum

s amples, gave a positive ELISA test result at the CPA central laboratory. Confirmatory serologic test

results were reported by CPA on 1 Oct 2011; the IP test result for serum from sow #619 tested was

suspect and the SN test result was positive for CSF at a titer of 1:40.

Due to the positive serologic test results, SENASICA issued a quarantine which was communicated with

the owner on 12 Oct 2011 . Resampling of the herd took place on 13 Oct 2011, the same date that the

Medina herd was resampled. Negative viru s isolation and real

- time PCR test results were reported by

CPA on 25 Oct 2011 . However, real

- time PCR test worksheets provided to APHIS by CPA show six positive

test results for whole blood samples taken during the resampling on 13 Oct 2011. Results for the positive

and negative controls run with the real

- time PCR tests suggest that the tests were valid.

The producer reported that the quarantine had been lifted recently and that he was currently sending

finished pigs to slaughter.

Sow #619 was not resampled on 13 Oct 2011, because she had been sen t to slaughter along with a

pseudorabies reactor sow. The producer stated that sow #619 had been sent to slaughter because of her

advanced age, although he admitted that the sow had always produced two healthy litters per year.

Maria Elvira II farm, owned by Señor Salvador Reyes Rogrig uez, located in Penjamo, Guanajuato , h as existed for approximately 30 years. The owner’s home is located on the farm premises. The farm raises

swine from farrow to finish in confinement. The swine do not have access to the outdoors, and entry of

people and animals is restricted by a perimeter fence and gate

. A bath and sprayer disinfects vehicles

entering and departing the farm at the access gate. The producer repor ted hi s inventory of swine as 170

- 175 sows, 3 -4 boa rs, 120 unweaned piglets, and 780 fattening pigs. The herd was closed to introduction

of new animals approximately five years ago. All replacem ent gilts are born on the farm. Semen provided

by the local swine producer’s association is used for artificial insemination.

Sr. Reyes employs four people to help on the farm , who change clothes at the farm entrance prior to

going to work with the swine. One employee is dedicated to tending the sow herd and another is a

d edicated mechanic. The pigs do not receive waste food. The swine diet is based on sorghum, of which

40% was grown by the farm owner and 60% was purchased this year. Feed is stored on the farm. A

commercial premix is mixed with the sorghum.Sr. Reyes rep or ted that blue eye disease occurred in the herd this year. Routine veterinary care of the

herd includes pseudorabies and blue eye disease vaccination, and deworming.

Visitors do not routinely enter the farm. Fattening pigs are moved from the nursery area in to the feeding

area in groups of approximately 30 pigs, and they remain in those groups until finished. One buyer

comes to the farm with a truck to pick up finished pigs and deliver them to a federally inspected

slaughterhouse (TIF plant #137 )

.

No additi onal surveillance ( perifocal sampling ) was conducted as a result of the investigation of the

Maria Elvira II farm. Sr. Reyes’ brother manages another pig farm co

- located on the same family

- owned

10 hectare property as the Maria Elvira II farm.

Sr. Reyes s uspects that the CSF seropositive sow (ear tag # 619 ) might have been vaccinated for CSF at

some time in her life, because she is an old sow, possibly 5

- 6 years old. Both the producer and the CPA

personnel reported that CSF vaccination ceased in that region in May, 2004, however.

The producer agreed to a plan for the APHIS team to conduct an on

- farm investigation, collecting tonsil

scrapings, nasal swabs, whole blood, and serum from growing pigs and from the six sows that tested

positive by real

- time PCR pos itive in Oct 2011. The producer also agreed to allow us to sacrifice any ill

pigs , if present, for necropsy. Guanajuato Comit é representatives offered to purchase sick pigs for

necropsy.



### On

**- farm investigation** 

Investigators: David Pyburn and Conrad Estrada (APHIS), Juan Car los Valladares (Sheesley Ent erprises ),

Jose L uis Tafoya.

We arrived at the farm at approximately 12:00pm. Due to the farm being located on a busy highway with

little room to park on the shoulder of the road, t he producer insisted that we park our vehicles inside the

farm gate. Our vehicles were disinfected by a gate dip and spray station as we drove on to the property.

Once inside the property

, w e established a ‘clean

- dirty ’ line inside the farm gate, organized our

equipment, and donned P PE. First, we walked through the entire facility to visually inspect the animals

. We did not observe clinical signs of illness suggestive of CSF. Overall the pigs looked healthy and we did

not see signs of disease other than an occasional cough in some of the pigs.

Blood was collected from sixty pigs for serum and whole blood testing. Two sows which tested positive

by real

- time PCR in Oct 2011 were available for resampling. In addition to serum and whole blood

collection, nasal swabs and tonsil scrapings were also collected from these two sows. Nasal swabs and

tonsil scrapings were also collected randomly from twenty

- eight of the sixty sampled pigs . The material

from each tonsil scraping was plac ed in a Whirl -P ak bag with a small amoun t (approx. 4 ml) of P BS. Both

nasal cavities were swabbed, and each swab was place in a red top vial with a small amount (approx. 1

ml) of PBS. Each sampled pig was identified with an ear tag. Pigs were chosen for sampling at random

from all pens that contained 10 to 1 4- week

- old swine and from some pens with slightly older swine not
yet ready for marketing. This sampling plan was designed to provide the best chance at finding CSF virus

in the herd (10 -14 week old pigs are more likely than other age groups to be shedding CSF virus in a ninfected herd) an d to allow trac ing of individual pig in the event test results warranted further

investigation.

We cleaned and disinfected our equip ment with Virkon ® and removed our PPE at the farm gate. Trash

was left with the producer, who said that he would burn it. Our vehicles were disinfected at the farm

gate as we left the farm. Samples were transported to a mobile lab provided by CENASA, which was

parked near the Maria Elvira II farm in Penjamo.

In the ‘dirty’ room of the mobile lab, M arta Chavez and Julie Gauthier packaged the samples into two

groups. Each set of samples consisted of tonsil scrapings, nasal swabs, whole blood, and serum samples.

One set was labeled for CPA, and the other set was labeled “Sav e for Consuelo Carrillo” for Dr. Carrillo to
use during the CPA central lab visit planned for 28 Nov 2011. Sample sets were placed in the refrigerator

of the mobile lab with the packaged samples from the Medina farm, to be transported to the CPA central

lab for analysis on the follow ing morning (17 Nov 2011).



### Observations

The field team appreciated the invitation to work with CPA, State animal health Comit é personnel, and

the producers, especially on sh ort notice. Producers, CPA, and Comit é personnel were very helpful and

pleasant to work with. Despite our many questions and unfamiliarity with their procedures, the

producers and field investigators were very patient and cooperative.

Field investigators acted in a professional manner and they were very c onscientious about biosecurity. It

was evident that the field investigators have the skills to observe the necessary biosecurity protocols and

take appropriate samples.

We found it very helpful to hav e the mobile lab available on

- site to process our samples. The mobile lab

personnel were extremely helpful and worked late hours to complete the sample processing. We hope

that this excellent resource is used frequently in Mexico.



### Recommendations

1. Field personnel were unaware of the positive real

- time PCR test results for the 13 Oct 2011

sa mples from both Medina (25 positives) and Maria Elvira II (6 positives). Field personnel were

given only the final rep ort at a later date, w hich stated that real

- time PCR test results for all

samples were negative . We asked SENASICA staff for an explanatio n for the final negative

interpretation of the positive real

- time PCR results on the worksheet, but we were not given an

explanation.

Communication between the laboratory and field personnel should be improved. Even

preliminary test results are helpful for field investigators, in order to plan resampling, form

epidemiological theories, and keep the owner informed and engaged productively in the

investigation. The laboratory can advise the field personnel about the most appropriate types ofsamples and methods of collection and preservation, in order to increase the probability that

the virus, if present, will be found.

2. Field personnel typically sample the sow herd only during investigations; they are not

accustomed to sampling younger animals. Sampling should focus on the animals and samples

most likely to harbor virus , if the objective is to find virus, or focus on animals likely to have

antibodies, if the object ive is to find antibodies. Take the right sample from the right animal at

the right time.

When hunting for CSF virus, the animals on which investigators should focus include:

a. Young pigs about 10

- 14 weeks old

b. Sick pigs

c. ‘ Poor

– doers ’ , runts, slow

- growing animals (redrojos)

The best samples for finding virus include:

d. Tonsil scrapings

e. Fresh tissue s: tonsil, spleen, distal ileum, lymph nodes

When hunting for CSF antibody, investigators should focus on collecting serum from:

f. Adult animals – sows and boars

g. Slow

- growing finishers

3. Resampling of far ms with positive test results from active surveillance should be prompt and

handled as a high priority. The investigation is most urgent when CSF compatible clinical signs or

epidemiological links to suspect farms are known.

4. Investigators should take a minimum of equipment on to the farm. Non

- durable equipme nt
(items that can’t be immersed in disinfectant) or disposable materials should be disposed of

upon leaving the farm. During our visit, investigators took an excess quantity of supplies on to

the farm and then took left

- over supplies (conical tubes, syrin ges, media, blood tubes , etc. ) off

the farm to be used again. This puts other farms at risk of introduction of disea se if these items

are used on another farm.

5. Investigators need supplies to remove samples from farms and maintain biosecurity. During our

v isit, investigators were planning to carry samples off the farm and transport them to the lab

without placing them in secondary containers or disinfecting them. Lacking sealable biohazard

bags or secondary sample containers, the APHIS team improvised with trash bags and

disinfected the bagged samples w ith Virkon 

### ® before transporting them to the lab. Field

investigators should be provided with secondary containers for transporting the samples in order

to avoid contamination of people and surfaces on the way to the laboratory.

6. Investigators were provided with cotton swabs for collecting samples for PCR testing. The use of

cotton swabs to collect samples for PCR reduce s the sensitivity of the test. Polyester swabs arerecommended for collecting samples for PC R testing, and these should be provided to the

investigator.

7. Investigators need smaller specula and appropriate spoons for collecting tonsil scrapings from

younger animals. The equipment that was provided to them was too big to be useful for smaller,

youn ger animals.

8. Trace

- back and trace

- forward investigations should be conducted more promptly and

aggressively for suspect CSF cases

. Tracing animal movements to and from suspect farms will

help to promptly confirm a case and to contain spread. Tracing anim al movements becomes

more difficult as time passes.