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Please note: This policy may be revised as the situation develops.

VIRULENT NEWCASTLE DISEASE (VND) VIRUS RESPONSE GOALS AND 

POLICY (STAMPING-OUT)

The USDA Animal and Plant Health Inspection Service (APHIS) goals for a vND virus

outbreak are to (1) detect, control, and contain vND virus as quickly as possible; (2) 

eradicate vND using strategies to protect public health and the environment, and stabilize 

animal agriculture, the food supply, and the economy; and (3) provide science- and riskbased approaches and systems to facilitate continuity of business for non-infected 

animals and non-contaminated animal products.

Achieving these three goals will allow individual facilities, States, Tribes, regions, and 

industries to resume normal production as rapidly as possible. The objective is to allow 

the United States to regain disease-free status without the response effort causing more 

disruption and damage than the disease outbreak itself.

The United States’ primary control and eradication strategy for vND in domestic poultry

and backyard production premises, as defined by international standards and the 

World Organization for Animal Health (OIE), is “stamping-out.” 

“Stamping-out” is defined in the OIE Terrestrial Animal Health Code as the “Killing of

animals which are affected and those suspected of being affected in the herd and, where 

appropriate, those in other herds which have been exposed to infection by direct animal 

to animal contact, or by indirect contact with the causal pathogen; this includes all 

susceptible animals, vaccinated or unvaccinated, on infected establishments.”

USDA will continue to evaluate with States, producers, and industry the potential use of 

any vND virus vaccine. However, stamping-out will always be part of any vND response 

policy, even if a protective vaccination strategy is implemented.

APHIS EPIDEMIOLOGICAL PRINCIPLES OF VND VIRUS RESPONSE

Three basic epidemiological principles form the foundation to contain, control, and 

eradicate vND in United States: 

1. Prevent contact between the vND virus and susceptible poultry.

a. This is accomplished through quarantine of infected poultry and movement 

controls in the Infected Zone(s) and Buffer Zone(s) (Control Area), along with 

biosecurity procedures to protect non-infected poultry.

b. Certain circumstances may warrant accelerating the depopulation or 

slaughter of poultry at risk for exposure to vND virus to decrease the 

population density of susceptible poultry.

c. There is a serious transmission risk posed by other people, material, 

conveyances, and animals that may have been in contact with vND virus and 

vND Response 2018

Stamping-Out & Depopulation Policy

May 30, 2018
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serve as mechanical vectors. Contact between poultry and these items 

should be prevented, and transmission risk mitigated through stringent 

biosecurity and cleaning and disinfection measures.

2. Stop the production of vND virus by infected or exposed animals. This is 

accomplished by rapid depopulation (and subsequent disposal) of infected and 

potentially infected poultry.

3. Increase the disease resistance of susceptible poultry to the vND virus. This may 

be accomplished by strategic emergency vaccination if a suitable vaccine is 

available and can be administered in a timely manner.

MASS DEPOPULATION AND EUTHANASIA

Mass depopulation and euthanasia are not synonymous, and APHIS recognizes a clear 

distinction. Euthanasia involves transitioning an animal to death as painlessly and stressfree as possible. Mass depopulation is a method by which large numbers of animals must 

be destroyed quickly and efficiently with as much consideration given to the welfare of 

animals as practicable, given extenuating circumstances.

Mass depopulation is employed in a vND response to prevent or mitigate the spread of 

vND virus through elimination of infected or potentially infected poultry. In 2007, the 

American Veterinary Medical Association (AVMA) issued best practice guidance that

stated “Under unusual conditions, such as disease eradication and natural disasters, 

euthanasia options may be limited. In these situations, the most appropriate technique 

that minimizes human and animal health concerns must be used.”

In 2013, the AVMA Guidelines for the Euthanasia of Animals continues to recognize 

depopulation, defining it as “The killing of animals in large numbers in response to an 

animal health emergency (e.g., catastrophic infectious disease, mass intoxication, natural 

disaster) where all due consideration is given to the terminal experience of the animal, but 

the circumstances surrounding the event are under-stood to be exigent and extenuating. 

Depopulation may not meet the requirements of euthanasia due to situational 

constraints.” This document also provides that further recommendations related to 

depopulation will be addressed in a separate document, the AVMA Guidelines for the 

Depopulation of Animals. This document continues to be under development.

In any event, euthanasia or mass depopulation should be provided to affected domestic 

poultry and backyard exhibition poultry as safely, quickly, efficiently, and humanely as 

possible. In addition, the emotional and psychological impact on animal owners, 

caretakers, their families, and other personnel should be carefully considered and

minimized.

APHIS STAMPING-OUT AND DEPOPULATION POLICY

For an initial detection in any State, when criteria for a confirmed positive have 

been met (per the current vND Case Definition, updated in May 2018), the APHIS 

Administrator or Veterinary Services Deputy Administrator (Chief Veterinary Officer of the 

United States) or their designee will authorize APHIS personnel—in conjunction with 

State and Tribal officials, and Incident Command personnel—to initiate depopulation, 
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disposal, cleaning, and disinfection procedures on the Infected Premises. Investigation of 

Contact Premises is also authorized at this time. Indemnity funds for depopulated 

poultry and reimbursement for cleaning, disinfection, and disposal activities are 

authorized by APHIS as funds are available.

For subsequent detections in a State, when criteria for a presumptive positive have been 

met (per the current vND Case Definition), depopulation and other response activities

may be authorized by APHIS and State/Tribal officials.

Best practices for containment and eradication of vND require rapid depopulation of 

infected poultry. Swift stamping-out is required to prevent the amplification of vND virus 

and subsequent environmental contamination. In all cases, depopulation activities must 

incorporate excellent biosecurity practices to control the vND virus and prevent further 

transmission: contaminated fomites (e.g., people and equipment) are a threat to the 

containment and eradication of the virus in domestic flocks.

APHIS DEPOPULATION GOAL

Due to the risk of virus amplification in infected poultry, poultry will be depopulated as 

soon as possible, with the depopulation goal of 24-hours or less after the criteria for a 

confirmed positive (initial detection in a new State) or presumptive positive (subsequent 

detections) have been met. The final determination to depopulate the entire Infected 

Premises, or specific houses on Infected Premises, will be made by State Animal Health 

Officials, or Tribal officials, and APHIS.

APHIS DEPOPULATION METHODS

In almost all cases, water based foam, carbon dioxide, or alternative methods will be the 

depopulation methods available to rapidly “stamp-out” the vND virus in poultry. Each 

premises will be evaluated individually, considering epidemiological information, housing 

and environmental conditions, currently available resources and personnel, and other 

relevant factors.