Introduction and Spread of HPAI VirusExposure of poultry to migratory waterfowl and the international movement of poultry, poultry equipment, and peoplepose risks for introducing HPAI into U.S. poultry. Onceintroduced, the disease can be spread from bird to bird bydirect contact. HPAI viruses can also be spread by manure,equipment, vehicles, egg flats, crates, and people whoseclothing or shoes have come in contact with the virus. HPAIviruses can remain viable at moderate temperatures for longperiods in the environment and can survive indefinitely infrozen material. One gram of contaminated manure cancontain enough virus to infect 1 million birds.

Potential Threat to Human HealthIn some instances, strains of HPAI viruses can be infectious to people. Human infections with the avianinfluenza viruses under natural conditions have beendocumented in since 1997. The H5N1 strain, identifiedin Hong Kong in 1997, was highly pathogenic for chickens and caused a limited outbreak in 18 people, 6 ofwhom died. In 2003, an H7N7 HPAI outbreak in theNetherlands resulted in human infections and onedeath. In mid-December 2003, a number of Asiancountries reported additional outbreaks of H5N1 HPAIin chickens and ducks. As of May 2005, almost 100cases of human infection had been reported in Vietnam, Cambodia, and Thailand, resulting in 53 fatalities.According to the World Health Organization, of particular alarm is the HPAI strain of most of these outbreaks—H5N1—which jumped the species barrier. Itcauses severe disease and may result in a high mortality rate in humans. For this reason, poultry personneland avian health-care specialists should wear adequatepersonal protective equipment, such as boots, coveralls,gloves, face masks, and headgear, and follow appropriate sanitary and disinfection procedures when on apremises known or suspected to be infected with HPAI.Please see the Web site of the Centers for DiseaseControl and Prevention for more specific information onpreventing disease transmission:<http://www.cdc.gov/flu/avian/professional/protectguid.htm.>Biosecurity Measures on the FarmPoultry producers should strengthen biosecuritypractices to prevent the introduction of HPAI into 

e

Purple discoloration of the comb may be an indicator of HPAI.

Here, healthy turkeys are compared with turkeys exhibiting signs ofdiarrhea and depression due to HPAI.

A biosecure broiler house protects poultry flocks from cominginto contact with wild or migratory birds.
High-Pathogenicity

Avian Influenza:A Threat to U.S. Poultry

The U.S. Department of Agriculture (USDA) prohibits discrimination in allits programs and activities on the basis of race, color, national origin,age, disability, and where applicable, sex, marital status, familial status,parental status, religion, sexual orientation, genetic information, politicalbeliefs, reprisal, or because all or part of an individual’s income isderived from any public assistance program. (Not all prohibited basesapply to all programs.) Persons with disabilities who require alternativemeans for communication of program information (Braille, large print,audiotape, etc.) should contact USDA’s TARGET Center at (202)720–2600 (voice and TDD). To file a complaint of discrimination, write toUSDA, Director, Office of Civil Rights, 1400 Independence Avenue,S.W., Washington, D.C. 20250–9410, or call (800) 795–3272 (voice) or(202) 720–6382 (TDD). USDA is an equal opportunity provider andemployer.Issued August 2005This leaflet supersedes “Highly Pathogenic Avian Influenza: A Threat toU.S. Poultry,” Program Aid No. 1704, which was issued in March 2004.

United States Department of AgricultureAnimal and Plant Health Inspection ServiceProgram Aid No. 1836

industry to conduct surveillance at breeding flocks, slaughterplants, live-bird markets, livestock auctions, and poultry dealers.

If HPAI were detected in U.S. poultry, APHIS veterinarians

would work quickly with their State counterparts and the industry to implement measures such as quarantine,control, and cleanup to prevent opportunities for the virus to spread.Report Suspicious SignsIf birds exhibit clinical signs of HPAI or may have beenexposed to birds with the disease, immediately notify Federal or State animal health officials.For more information about HPAI or biosecurity practices,contact:USDA, APHIS, Veterinary Services Emergency Management4700 River Road, Unit 41 Riverdale, MD 20737–1231Telephone (301) 734–8073 Fax (301) 734–7817For public health information, contact the Centers for Disease Control and Prevention in Atlanta, GA, at (404) 639–3311.Current information on animal diseases and suspectedoutbreaks is also available on the Internet at<http://www.aphis.usda.gov>.