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Virulent Newcastle 

Disease Virus Response

Surveillance Sampling Backyard

Premises in Control Area

Please note: These procedures may be revised as the situation develops. June 5, 2018

DEFINITIONS

Infected Premises: Premises where a presumptive positive case or confirmed positive case exists 

based on laboratory results, compatible clinical signs, virulent Newcastle disease (ND) case 

definition, and international standards.

Contact Premises: Premises with susceptible poultry1that may have been exposed to virulent 

Newcastle disease virus (vNDV), either directly or indirectly, including but not limited to exposure 

to animals, animal products, fomites, or people from Infected Premises.

Infected Zone: Zone that immediately surrounds an Infected Premises.

Buffer Zone: Zone that immediately surrounds an Infected Zone or Contact Premises.

Control Area: Consists of an Infected Zone and a Buffer Zone.

Foreign Animal Disease Investigation: An investigation conducted according to VS Guidance 

Document 12001 (Ready Reference Guide for investigations is here)

INTRODUCTION

An Infected Zone and Buffer Zone (Control Area) will be created around an Infected Premises. This 

document provides surveillance guidance for non-commercial backyard poultry1 premises within a 

Control Area. Surveillance activities and associated testing should be based on recommendations 

of the Unified (State-Federal) Incident Command; this guidance may require further modification 

based on epidemiological and situational information.

Newcastle disease, caused by vNDV, is endemic in a number of countries in Asia, the Middle East, 

Africa, and the Americas. Newcastle disease was detected in backyard poultry in California in 2018. 

Previous ND outbreaks in poultry the United States occurred in the States of California (2002–

2003), Nevada (2003), Arizona (2003) and Texas (2003). Virulent NDV is endemic in wild 

cormorants and non-virulent forms of ND are endemic in poultry. There are non-virulent strains of 

NDV endemic in poultry. This document reflects the epidemiological information known about the 

behavior of vNDV from knowledge gained in the 2003–2004 U.S. outbreak. 

 

1 For this document, ‘poultry’ is defined as any domesticated bird raised for food, eggs, or fiber and used in exhibitions or 

shows. This includes chickens, turkeys, ducks, geese, swans, pheasants, partridges, grouse, quail, guinea fowl, pea fowl, 

pigeons, doves, ostriches, emus, rheas, and cassowaries.
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PRIORITIES FOR SURVEILLANCE ACTIVITIES IN THE CONTROL AREA

Passive Surveillance

Passive surveillance is conducted at all times in the United States through foreign animal disease 

investigations per VS Guidance Document 12001. In the event of a foreign animal disease 

detection, passive surveillance should be intensified through rapid and clear communication to all 

producers in the Control Area.

Reports of clinical signs or unusual mortality and morbidity from backyard producers (sick bird calls)

are investigated as rapidly as possible. However, sick bird calls may overwhelm available resources,

particularly when investigation and/or management of Infected and Contact Premises are not

complete. In this case, the IMT may recommend triaging disease investigations on backyard

premises using criteria such as morbidity and mortality, clinical signs for ND and risk factors for 

exposure to vNDV. These parameters should be based on the best information available, and should

be developed in coordination with IMT, State/Tribal officials, and subject matter experts. Premises in

the Infected Zone should be prioritized over those in the Buffer Zone.

For sick bird calls on backyard premises, a Foreign Animal Disease Diagnostician (or individual

designated by the IMT) should:

1. Immediately investigate each sick bird call, if resources allow.

2. If necessary, prioritize the premises in the Infected Zone and prioritize the premises meeting 

the criteria for further investigation.

3. Schedule an appointment to collect samples as quickly as possible.

4. Conduct diagnostic testing according to sampling recommendations, submit samples to

designated National Animal Health Laboratory Network (NAHLN) lab as indicated by the IMT

(provided in “Sampling Scheme for Poultry” below).

Active Surveillance

1. Create an inventory of the bird2 populations in the Control Area.

a. Identify all the premises with birds in the Control Area. This can be done by phone or 

house visits.

b. Identify any auctions, markets, or exhibitions of birds in the Control Area and consider 

sampling at these events following the sampling scheme below.

2. Interview the owner of the premises about any birds residing on the premises.

a. If birds are present, determine if the premises is high-risk for exposure to vNDV (see 

Table 1). 

b. Record contact with owner and risk-status of birds on the premises. 

3. Conduct a surveillance visit to the high-risk premises identified in item 2 above. 

a. Visually inspect the birds and sample following the “Recommended Bird Sampling 

Scheme” below.

b. Prioritize visits to premises with sick or dead birds. All premises with sick or dead 

birds should be visited. 

c. Aim to also visit all remaining high-risk premises. However, if resources are limited, 

 

2

‘Birds’ includes ‘poultry’ as described above, as well as the birds in the Orders Psittaciformes (parrots, parakeets, macaws, conures, 

cockatoos) and Columbiformes (pigeons, doves). 
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select a minimum number of remaining premises to visit according to Table 2. 

Sampling the indicated number of premises will result in 0.95 probability that at least 

one positive premises will be detected if the prevalence of vNDV among additional 

premises in the Control Area is 0.5 percent or greater.

a Follow sample size guidelines described in next section

Identify and contact all 

premises with birds in the 

Control Area in person or 

by phone

Interview owner to assess 

premises risk status and 

plan surveillance 

activities

Birds with clinical signs

High risk

Visit premises and collect 

samples in every case a

No clinical signs, but risk 

factors present as per 

Table 1

High risk

Visit premises and collect 

samples a

If resources limited, use 

representative sample of 

premises as per Table 2

No clinical signs, no risk 

factors as per Table 1 

Lower risk

Record findings, including 

absence of clinical signs

Guidance for risk based surveillance to detect infected 

premises in the Control Area
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RECOMMENDED BIRD SAMPLING SIZE AND SCHEME

Select birds to sample and follow the Recommendations for Collecting Specimens from Poultry for 

Viral Diagnostic Testing (WI-AV-0020 available here) for detection of vNDV. Oropharyngeal or 

tracheal swabs are preferred for gallinaceous birds and cloacal swabs for non-gallinaceous birds3. 

Do not combine swabs from different species or different sample types. 

1. Select birds to sample. If there are multiple houses or flocks on the premises, sample each

separately according to the guidelines below. Prioritize sampling of sick and dead birds

regardless of vaccination status. 

a. For unvaccinated populations, sample two 5- or 11- swab pools. Sampling two 5-

or 11- swab bird pools is sufficient to detect vNDV with 95 percent confidence if 

prevalence across birds is 40 percent (using an estimated test sensitivity of 91

percent).

• If there are fewer than 5 birds, sample all the birds. 

b. For vaccinated populations, sample 30 birds using 5- or 11- swab pools. A 30-bird 

sample can detect vNDV with approximately 95 percent confidence if within-flock 

prevalence among birds considered high-risk of exposure is 10 percent (using an 

estimated test sensitivity 91 percent).

• If there are fewer than 30 birds, sample all the birds. 

2. Prepare, package, and process swabs for laboratory submission according to the guidance 

found in the FAD Investigation Manual.

3. Repeat visits and sampling on premises are not necessary, unless clinical signs continue or 

escalate. 

4. Encourage owner to call if clinical signs, morbidity, and/or mortality are observed. 

Table 1. Risk factors leading to birds to be classified as high-risk, a higher probability exposure to 

virulent Newcastle disease.

Sick and dead birds and/or history of sick and dead birds.

Close geographic proximity to other premises containing outdoor birds.

Other demographic characteristics in common with known virulent ND infected premises.

Newly arrived birds and young birds and/or a high likelihood/reported history of birds moving 

onto or off of the premises.

Birds from multiple owners on a single premises.

Similar farm or bird level risk factors as other cases (identified by IMT).

Birds used for exhibition or commingled for any purpose.

Any number of birds with access to the outdoors. 

Premises with gamefowl

 

3 Gallinaceous birds are chickens, turkeys, pheasants, partridges, grouse, quail, guinea fowl, and pea fowl, as well as all other birds are nongallinaceous birds.
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Table 2. Number of premises to be sampled in the Control Area if the total number of premises in the 

Control Area cannot be visited.*

No. of Premises Minimum No. of Premises

to be Sampled for 0.5% prevalence

Minimum No. of Premises

to be Sampled for 1% prevalence

less than 100 Sample all Sample all

200 Sample all 163

400 327 221

600 398 247

1,000 474 271

1,500 519 285

2,000 544 292

3,000 570 299

5,000 593 305

10,000 611 309

infinite 629 314

1 Sample sizes computed using Cannon, 2001.

* Assuming a 95% herd-level sensitivity, sampling the indicated number of premises will result in 0.95 probability that at least 

one positive premises will be detected if the prevalence of virulent Newcastle disease virus is at least 0.5% or 1% in the 

population of premises at the time of sample collection.

DOCUMENTATION

As with all surveillance activities, documentation is critically important. EMRS2 is the system of 

record for all virulent ND outbreaks in the United States. Relevant data regarding backyard 

surveillance activities must be entered into EMRS2 in as close to real time as possible. This data 

may be reported internally and externally through situation or close-out reports or other means.

At a minimum, the following items are important to maintain and report. Refer to IMT guidance for

how to appropriately record these and other data:

 Number of backyard premises in Control Area.

 Number contacted, and means of contact, for passive surveillance.

 Number of visited and sampled premises for passive surveillance.

 Number of premises contacted by phone for active surveillance.

 Number of premises visited and sampled for active surveillance.

 Total birds sampled per premises.

 Laboratory results for all submissions.

FOR MORE INFORMATION

USDA APHIS VS. Draft August 2014. Newcastle Disease Response Plan: The Red Book. 

Recommendations for Collecting Specimens from Poultry for Viral Diagnostic Testing (NVSL WI-AV0020) 

USDA APHIS VS. 2018. FAD Prep Materials and References. www.aphis.usda.gov/fadprep.