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Control of Highly Pathogenic Avian Influenza (HPAI) in Poultry 1 Learning Objectives • Understand how Influenza A is spread in poultry • Understand how highly pathogenic avian influenza outbreaks happen\ • Know how to detect and control highly pathogenic avian influenza outbreaks via multiple measures 2 Session Outline • Influenza A and highly pathogenic avian influenza (HPAI) in birds • How to prevent or control HPAI among poultry – Decontamination – Surveillance and biosecurity – Vaccines 3 Influenza Virus Type A most likely to cause a panzootic • Most likely to change • Different strains mix in one animal or human host (reassortment) • People lack immunity to the resulting new subtype (highly pathogenic) 4 Influenza A • Infects many birds, animals, humans – Water fowl and poultry – Humans (mixing vessels) – Pigs (mixing vessels) – Other mammals • Subtypes based on “HA” and “NA” surface proteins – 16 HA, 9 NA subtypes exist – H1N1, H1N2, H3N2 are circulating human subtypes 5 Transmission of Influenza A 16 HAs 9 NAs Non-human virus Human virus Reassortant virus 6 How does HPAI happen? • Carried by migrating wild birds to domestic poultry • Virus changes and becomes more deadly in poultry • Difficult to control and eliminate because it spreads rapidly 7 Signs of Infection in Birds • Wild waterfowl asymptomatic • Domestic ducks recently found to be asymptomatic 8 Signs of Infection in Birds • Mildly ill birds – Ruffled feathers – Fewer eggs – Breathing problems • Very ill birds – May have bleeding under skin of the legs – May have swollen eyes, wattle – Usually die within 2 days 9 How Birds Spread HPAI • Direct contact – Feces • Improperly disposed carcasses – Respiratory secretions 10 How Humans Spread HPAI • Hands • Fomites • Airborne particles • Contaminated equipment 11 How to Prevent or Control Highly Pathogenic Avian Influenza 12 Potential Control Measures • Surveillance • Biosecurity • Restricting movement of birds • Destroying birds humanely • Disposing of carcasses properly • Vaccines 13 Disease Surveillance • Purpose – Rapidly detect and respond to disease – Learn about virus mutations • Methods – Country-specific, depending on risk – Signs and symptoms reporting – Serologic surveys – Sentinel surveillance 14 Increasing Surveillance Effectiveness • Make HPAI a notifiable disease • Establish a formal system to detect and investigate outbreaks • Develop technical capability to diagnose HPAI in your country / region 15 Increasing Surveillance Effectiveness (cont’d) • Participate in the regional surveillance and diagnostic network • Conduct surveillance at a minimum of every six months • Monitor medical status of outbreak control workers 16 Disease Surveillance • In areas where HPAI is documented • In areas where HPAI could appear • Sensitize and educate the community – Poultry die offs – How to report to animal health authorities – Why to report (and any incentives) 17 Disease Surveillance Rapid reporting enables animal health agents and rapid response teams to: • Investigate and record key information • Analyze specimens 18 Biosecurity All measures taken: • To keep disease out of a farm • To keep disease from spreading from an infected farm 19 Ensuring Biosecurity • Maintain a barrier from the outside world • Separate new poultry for 2 weeks • Prevent unknown birds from entering flock • Control human traffic into the farm • Use “all in – all out” production Note: Infected poultry and poultry products do NOT enter the food supply. 20 Poultry-Raising and Biosecurity Security Marketing Sector 4 Backyard poultry Products consumed locally Sector 3 Low to minimum Products enter live bird markets Sector 2 Moderate to high Products often marketed commercially Sector 1 High Products marketed commercially 21 Restricting Movement and Mixing • Farm movement control – Birds – People – Objects • Bird markets – Close – Depopulate – Disinfect Deutsche Presse-Agentur • Border patrols 22 Destruction and Disposal of Birds in Affected Areas • Kill birds humanely – Consider compensation for farmers • Dispose carcasses safely – Do NOT contaminate local water sources • Clean and disinfect • Restock after 21 days – Only after official inspection 3/1/2006 Reuters. Karachi 23 Poultry Vaccines Advantages: • Inactivated (killed) whole AI virus available • Effective against H5 subtype • Good resistance to infection • Reduced amount of virus in environment Disadvantages: • Administered by injection • Does not eliminate possibility of infection Potential future vaccine: • New recombinant fowlpox vaccine 24 Summary • Target high risk flocks • Isolate domestic birds from wild water fowl • Consider compensation to encourage early reporting 25 Glossary Highly Pathogenic Avian Influenza (HPAI) Influenza infection in poultry that causes severe illness and often death. Can be transmitted to humans resulting in severe illness or death. Panzootic A disease affecting animals of many species, especially over a wide geographic area. 26 Glossary Disease Surveillance The ongoing systematic collection and analysis of data and the provision of information which leads to action being taken to prevent and control a disease. Sentinel Surveillance Disease surveillance based on selected population samples chosen to represent the relevant experience of particular groups. 27 References and Resources • Guiding principles for Highly Pathogenic Avian Influenza Surveillance and Diagnostic Networks in Asia. FAO Expert meeting on Surveillance and Diagnosis of Avian Influenza. Bangkok, Thailand, 2123 July, 2004. http://www.fao.org/ag/AGAinfo/subjects/en/health/dis eases-cards/Guiding%20principles.pdf • Preparing for Highly Pathogenic Avian Influenza: A Manual for Countries at Risk . V. Martin, A. Forman, J. Lubroth. Updated 16 February 2006 http://www.fao.org/docs/eims/upload/200354/HPAI_m anual.pdf 28 References and Resources • A Global Strategy for the Progressive Control of Highly Pathogenic Avian Influenza (HPAI) . Food and Agriculture Organization, World Organisation for Animal Health, World Health Organization http://www.fao.org/ag/againfo/subjects/documents/ai /HPAIGlobalStrategy31Oct05.pdf • PROTECT POULTRY – PROTECT PEOPLE Basic advice for stopping the spread of avian flu. Emergency Centre for Transboundary Animal Diseases. FAO, Agriculture Department, Animal Production and Health Division http://www.fao.org/docs/eims/upload//207623/FAO_H PAI_messages.pdf • Additional FAO Animal Health Information Resources Available at: http://www.fao.org/ag/againfo/subjects/en/health/diseases- 29 cards/avian_recomm.html