# Presentation: 511680

## Infectious Diseases that may be Transmitted to Humans from Animal Farm Operations

**John L. Cicmanec, DVM, and James E. Smith, Jr., D.Sc.**
**Technology Transfer Branch   **
**                 ****Technology Transfer & Support Division**
**          ****National Risk Management Research Laboratory**
**U.S. Environmental Protection Agency**
**Cincinnati,**** OH**

## Outline

- Why the _concern_ about Animal Waste?
- The _supporting_ epidemiologic evidence
- Calculation of the present _cost_
- Features of specific diseases that        determine Risk Management choices
- Quantitative Microbial Risk Assessment
- Potential Risk Management Options

## OUR HYPOTHESIS

- The following pathogens account for 2/3 of food related deaths (in order of greatest frequency):

- P	*Salmonella *spp*.*
- P	*Listeria monocytogenes*
- P	*Campylobacter *spp.
- P	*E. coli* 0157:H7

**Field application of animal waste increases the risk of water-and food-borne diseases.**

- ~75 million cases of water- and food-borne illness are reported annually.

## MANURE-RELATED HUMAN EPIDEMICS

## Cost Summary for Waterborne Pathogens in U. S

| Pathogen | Percent in Water | Total Cases | Hospital-izations | Total Deaths | Cost $ (in millions) |
| --- | --- | --- | --- | --- | --- |
| Campylo-bacter  | 20 | 390,000 | 2107 | 20 | 160-270 |
| Salmon-ella spp. |  3 |  45,000 |   520 | 20 |  60-245 |
| E. coli O157:H7 | 15 |  11,232 |   332 | 10 |  90-150 |
| Listeria monocyto-genes | 12 |       329 |   203 | 66 |  27-35 |
| Crypto-sporidium parvum | 70 | 210,000 | 31,500 | 70 | 150-270 |
|  |  |  |  |  | 510-970 |

## Pathogens of public health concern and their 

**agricultural sources.**

**___________________________________________**

**   ****Pathogen                                  Animal Source   **

**__________________________________________**

***Salmonella *****spp**

**poultry, swine, cattle**

***Campylobacter *****spp**

**poultry, cattle**

***E. coli *****0157:H7**

**cattle**

***Listeria monocytogenes***

**cattle, poultry**

***Yersinia enterocolytica***

**swine**

***Clostridium perfringens***

**poultry, swine, cattle**

***Cryptosporidium parvum***

**cattle**

***Giardia lamblia***

**cattle**

**__________________________________________**

## Comparing Risks - E. coli O157:H7

**In hamburger**** per 25 gram aliquot- one in 500,000 (Marks, et al 1998)**
**Development of ****Hemolytic-Uremic Syndrome****- one in 3.7 million; ****Mortality**** ****- ****one in 19 million (Cassin, et al 1998)**
**Infection ****drinking water**** in the United States - one in 6.9 million (Cicmanec,2000)**

## Escherichia coli  O157:H7

**Verocytotoxin - like Shigella toxins**
**Can cause death in humans esp. children**
**As few as 10 cells can be infective**
**Primary source to humans is cattle manure**
**1% incidence in cattle; 25% in some herds**
**Remains viable in soil for 4 months**

## Potential Public Health Risk of Campylobacter in New Zealand

**A reportable disease - incidence has risen from 225 to 334/100,000**
**Routinely detected at low levels in ****city drinking water**** samples**
**Peak time of occurrence is September - the height of calving season**
**5% of all cases are recreational exposure**

## Salmonellosis – Diane Lightfoot

*******Only 3% of outbreaks are waterborne**
*******The present recommendation is **_**not**_** to treat with antibiotics- 75%+ are resistant**
******* Danish practice is to slaughter infected poultry rather than vaccinate**

## Infective Dose50 for Humans

***Salmonella typhi                          100,000***
***                       ******Hornick, 1970***
***Vibrio cholera                                  1,000******              ******(Type 01)******        ******Clements, 1984***
***E. coli  O157:H7******  ******Powell,2000******       ******       10***
***Giardia lamblia******  ******Rendtorff,****** ******1954******         ******  1***

## Infective Dose50 for Humans (Viruses)

**Human echovirus               17**
**Human poliovirus                2                    (SM strain)**
**Human poliovirus                2                 (Fox strain)**
**Rotavirus                           0.9**

## Presently Used Management Practices

**Vegetative buffer strips**
**Monitoring indicator organisms**
**  “****Indicators can be used to     evaluate Risk Management practices but not to perform risk assessments”**
**   ****Jameson effect**
**   ****Are pathogens aberrant? **
**Attempts to control nutrients**

## ORD   Recommendations

**Facultative Lagoon Storage**
**Windrow Composting**
**Air Drying**
**Anaerobic Digestion**
**Aerobic Digestion**
**Lime Stabilization**

***Note: Very similar to Class B Sludge Treatment Processes***

## ?

- Sewage
- Sludge

**Event Tree: BSE from abattoir to soil via biosolids**

- Rendering
- Plant

- Sewage

- Sewage
- Effluent

- Raw
- Sewage
- Sludge

- Destroyed
- by Sludge Treatment

- Infectivity
- remaining
- on top soil

- Decay in soil
- and leaching

- Sludge particle

- Soil particle

**0.99**

**0.01**

**0.0**

**1.0**

**0.9982**

**0.0018**

**?**

**0.0**

**1.0**

- Brain/spinal
- cord of
- carcass at
- abattoir

- Dilution

**0.0**

**1.0**

- Source: P. Gale

## Decision-Tree Risk Assessment for Root Crops after Biosolids Application (No. of Infections/yr) Paul Gale

_**Organism**_**        **_**12 month**_**                   **_**10 month**_
**                        **_**Mesophilic anaerobic**_**   **_**Pasteurization**_
**                                **_**digestion**_
**Salmonella              10****-18****                     10****-17**
**Listeria                    10****-28****                     10****-27**
**Campylobacter        10****-53****                     10****-43**
**E. Coli O157        3.3 x 10****-8****                 10****-15**
**Cryptosporidium      ****0.022                   1.0**
**Giardia                      10****-7****                  2.8 x 10****-9**
**Enteroviruses           10****-15****                   10****-16**

## Ratio of Reported Cases to Actual Number of Cases

_**Disease**_**     **_**Ratio**_**            **_**Comment**_
**Botulism      2X    Very tight ratio because public**
**                             ****awareness is high & is fatal**
**Brucellosis 14X    Based on published estimates**
**                             ****from post-infection serology**
**C. jejuni     38X     Based on Salmonella; mode of**
**                             ****transmission is similar**
**E. coli 157  20X    Based on outbreaks in small **
**                             ****towns**
**Listeriosis     2X    A small ratio because**** ****systemic**
**                             ****infections are severe**

## Ratio of Reported Cases to Actual... (cont.)

_**Disease**_**      **_**Ratio**_**    **_**Comment**_
**Norovirus       10X  Based on serologic **
**                               ****data following an **
**                               ****outbreak**
**Giardiasis       20X  Sensitivity surveillance**
**                              ****in Vermont & Wisconsin**
**Crypto-           45X  Based on estimated **
**Sporidiosis              number of reported **
**                                ****cases from a FoodNet study**
**Salmonellosis 40X  Chicago terrorist episode  **