Highly Pathogenic Avian Influenza (HPAI) on the Poultry Farm

1. Highly Pathogenic Avian Influenza (HPAI) on the Poultry Farm

2. Learning Objectives • Describe normal transmission of Influenza A • Describe development of HPAI (vs. LPAI) • Describe control measures • Surveillance • Enhanced biosecurity • Movement control • Destruction of contaminated birds and fomites • Role of vaccines and antivirals

3. Session Overview • Influenza transmission basics • Influenza infection in wild and domestic birds • Sources of infection on the farm • Surveillance • Biosecurity measures • Guidelines for poultry-related occupations

4. Influenza A • Infects multiple species • Humans • Water fowl (primary reservoir) and domestic fowl • Pigs (mixing vessels) • Other mammals affected by certain sub-strains (horses, dogs, cats, tigers, etc)

5. DIRECT Transmission of Influenza A 16 HAs 9 NAs Non-human virus Human virus Reassortant virus

6. Pathogenicity of AI • AI strains characterized by pathogenicity in chickens • LPAI (Low-pathogenic avian influenza) • Mild disease in poultry • Most strains are LPAI • LPAI strains can mutate into HPAI • HPAI (Highly pathogenic avian influenza) • Severe illness and high fatality in poultry • Some poultry have no illness (ducks)

7. Development of HPAI • Low pathogenic AI strains that are most capable of mutating into HPAI and causing epizootics • H5 and H7 • Most H5 and H7 are LPAI • Disease • Human HPAI infection via contact with infected sick or dead birds • MIld human LPAI infections have been documented • Wild birds can introduce LPAI into domestic flocks • Can evolve into HPAI • Aggressive intervention required for LPAI

8. Signs of LPAI Influenza in Birds • Wild waterfowl, gulls, shorebirds are natural hosts for influenza viruses • Usually no symptoms • Infection in non-reservoir can result in either: • No outward disease (LPAI) • Mild infection (LPAI) • Ruffled feathers • Reduced egg production • Respiratory symptoms • Can be easy to miss!

9. Signs of HPAI Infection in Birds • Causes more lethal infection • Difficult to miss - severe disease/sudden onset • Facial edema, swollen and cyanotic combs and wattles, drastic decline in egg production • Internal hemorrhaging of lungs and other organs • Rapid contagion • Mortality near 100% within 48 hours • Role of domestic ducks in spread of HPAI NO SYMPTOMS!

10. Domestic and wild birds Ducks, geese, sparrows, poultry, pets Pigs, horses, marine mammals, ferrets, minks Natural infection contracted from exposure to birds Tigers, leopards, domestic cats, dogs Ingestion of infected poultry Avian Influenza in other Animals

11. Feces Respiratory secretions Improper disposal of carcasses Sources of Infection

12. Humans Hands, hair, clothing, footwear Contaminated equipment Potential Sources of Infection for Humans Investigators must practice biosecurity when entering / leaving a potentially contaminated farm

13. Measures for Prevention, Control and Eradication of HPAI in Poultry • Increased disease surveillance in high risk areas • Increased biosecurity on poultry farms • Control of movement of birds and fomites • Rapid, humane destruction of infected and at risk poultry and proper disposal of carcasses

14. Disease Surveillance • H5 diagnosis is reportable to USDA • Conduct in areas where disease has been or could be • Detect and investigate outbreaks • Education on symptoms (esp. rural farmers) • How to report / who to report to • Incentives for reporting

15. Disease Surveillance • Enable animal health agents/rapid surveillance and response teams to: • Investigate and record key information • Get specimens • Send specimens rapidly to a designated laboratory in a “reverse cold chain”

16. Increasing Biosecurity • All the measures taken • to keep disease from coming into a farm (Bioexclusion) • to prevent the transmission of a disease within an infected farm and to other farms (Biocontainment)

17. Types of Poultry-Raising & Biosecurity • Sector 1 • Backyard poultry • Birds/products consumed locally • Sector 2 • Low to minimal bio-security • Birds/products enter live bird markets • Sector 3 • Moderate to high bio-security • Birds/products often marketed commercially • Sector 4 • High level bio-security • Birds/products marketed commercially

18. Ensure Biosecurity through Bioexclusion • Keep poultry indoors • Separate from the outside world • Remove or disinfect all sources of infection • Prevent unknown birds from entering flock • Control human, vehicular, and equipment traffic onto the farm • Use “all in – all out” production • Separate new poultry for 2 weeks • Clean and disinfect when “all out” AI can remain viable in tissue, feces and water for a long period of time (days to weeks)

19. Biocontainment on Infected Farms • Depopulation of infected and exposed birds • Movement control • On and off farm • Bird markets and swap meets closed and disinfected • Testing of potentially infected birds

20. Destruction or Disposal of Birds in Affected Area • Humane killing of birds • Carbon dioxide • Dislocate neck • Others • Disposal per EPA guidelines • Burn • Bury • Do NOT dump in local water sources • Cleaning and disinfection • Allow 21 days before getting more poultry 3/1/2006 Reuters. Karachi

21. When to Investigate • Clinical signs of HPAI • Local or regional surveillance detects possibility of infection • Lab tests confirm infection Virus isolation necessary to distinguish from other fatal poultry disease (fowl cholera, Newcastle disease, etc.) • Institute proper chain of reporting, disposal, and testing for infected area and surroundings

22. Vaccination for Poultry • Inactivated whole AI virus • Effective against H5 subtype • Good resistance to infection • Reduced amount of virus in environment • May have subclinical infection • Can still shed virus • Administered by injection

23. Vaccination and Antivirals for Poultry • Vaccination maylimit exportation • New recombinant fowlpox vaccine? • Antivirals for only for humans, not birds • Potential for resistance

24. Occupational Guidelines

25. Occupational Guidelines • For persons in contact with healthy birds in HPAI-free zones • Increased vigilance and hazard communication • Standard Personal Protective Equipment (PPE) • Risk assessment for processing of species that may exhibit asymptomatic disease (e.g. ducks)

26. Occupational Guidelines • For persons in direct contact with known or suspected HPAI materials • Training, basic infection control, PPE to include respirators and antiviral prophylaxis • Surveillance and monitoring of workers • Evaluation of ill persons

27. Occupational Guidelines • For exposure to a known HPAI source • Disposable particulate respirators (N-95 or greater); or powered air purifying respirator • Current season influenza vaccine Reduces possibility of dual infection with human and avian influenza, which could lead to reassortment

28. Occupational Guidelines • For persons in contact with live or dead poultry or materials later identified as HPAI • Medical evaluation • Post-exposure prophylaxis • Surveillance for respiratory-related symptoms • Fever • Respiratory symptoms • Conjunctivitis

29. Take Home Message • Isolate domestic birds from wild water birds • Multiple agencies work with USDA, establish ties to ensure swift, effective response

30. Breakout Groups

31. Helpful web sites • Centers for Disease Control: www.cdc.gov • World Health Organization: www.who.int/en/ • World Organization for Animal Health: www.oie.int • UN Food and Agriculture Organization: www.fao.org • US poultry and Egg Industry Associationhttp://www.poultryegg.org/ • USDA Avian Influenza website http://www.usda.gov/wps/portal/usdahome?navid=AVIAN_INFLUENZA&navtype=SU