AVIAN INFLUENZA An Animal Health Perspective

1. AVIAN INFLUENZA An Animal Health Perspective Dr. Thomas J. Holt State Veterinarian/Director FDACS, Division of Animal Industry

2. Etiology • Orthomyxoviridae • Envelope • Glycoprotein projections/surface antigens • Hemagglutinin (HA) and neuraminidase (NA) • 15 hemagglutinin and 9 neuraminidase antigens • A Type designation (A - only, B or C only present in humans) • Primary reservoir is wild birds, especially water fowl • H5, H7 strains of primary concern 2

3. Avian Influenza • Incubation Period 3-14 days • Highly contagious (100%) • Low-Path - low mortality, recover in 3 weeks • High-Path - >95% mortality within 24 hours 3

4. Disease in Poultry • Low pathogenic strains • mild to severe respiratory symptoms • egg production may drop by up to 45% and take 2—4 weeks to recover • High pathogenic strains • severe respiratory distress, diarrhea, nervous signs • watery eyes and sinuses • cyanosis of the combs, wattle and shanks • swelling of the head 4

5. Gross Lesions Swollen head, edema Paint brush hemorrhage Excess mucous, hemorrhage 5

6. Why Control Low-Path H5/H7 AI? • Significant carcass condemnations • Significant egg production losses • Inter-state and international trade embargoes • Mutation to High Path • Potential Zoonotic Disease 6

7. Infection and Depopulation Spatial Patterns March 12 through June 24, 2002 7

8. Turkey or Chicken Flock Virginia: All Turkey and Chicken Flocks As of April 18, 2002 8

9. 2002 VA AI Outbreak H7N2 March 7-12 Index Case Confirmation Voluntary Company Depopulation On-Site Burial March 28 20 Positive Flocks State/Company Control Measures Controlled Slaughter Permitted 9

10. 2002 VA AI Outbreak H7N2 10

11. Virginia: Infected Flocks (89) As of April 18, 2002 11

12. 2002 VA AI Outbreak H7N2 12

13. 2002 VA AI Outbreak 197 Positive Farms/ 1000 Farms 20% 4.7 million birds/ 56 million birds 8.4% 13

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16. Types of farms affected No. of farms affected …………………………...………. 197 Turkeys (78%): Turkey breeders ……………………………………… 28 Commercial turkeys (meat) ……………………125 Chickens (22%): Broilers (chickens) ……………..........................13 Broiler breeders (chickens) ………….………..29 Layers (chickens) ………………………………….…… 2 No positives found in area backyard flocks or wild waterfowl. 16

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19. Incident Command Post 19

20. VIRGINIA AVIAN INFLUENZATASK FORCEPersonnel 20

21. Virginia AI Task Force • Mission: To control low path AI • Identify and eliminate foci of infection • Prevent spread of disease • Priorities: • 1. Safety of Incident Personnel and Involved Public • 2. Adherence of Strict Biosecurity Measures by Incident Personnel 21

22. Three Focus Areas • Surveillance • Eliminate foci of infection • Biosecurity 22

23. Laboratory Diagnosis • Viral isolation • AGID • ELISA • Battery of specific antigens to identify its serologic identity (HA and NA type). • Sera from infected chickens usually yield positive antibody tests as early as 3 or 4 days after first signs of disease. • Real time reverse transcriptase polymerase chain reaction (rT-RT-PCR) 23

24. Avian Influenza Tests AGID Directigen RT-PCR Virus Isolation Virus Level 0 7 14 21 28 Days Post-Infection (Flock) 24

25. AI Surveillance 25

26. Barrel Surveillance 26

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28. Elimination of Foci of Infection • Rapid humane euthanasia of infected flocks • Rapid removal of carcasses • Disposal – a major challenge • Closing of Houses followed by testing • Cleaning and Disinfection of houses • Implementation of Biosecurity Measures 28

29. Carcass Disposal Methods • On Farm Burial • Incineration • Landfill • Composting 29

30. Biosecurity 30

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32. Incident Command System • Incident Command Staff • Planning • Administration and Finance • Logistics • Operations 32

33. Incident Commanders 33

34. Forest Service 34

35. Army 35

36. Department of Health and Human Services 36

37. Incident Command System Daily Meeting 0700 Surveillance Personnel (All) 0800 Daily Briefing (All w/o Surveillance) 1300 Chiefs Meeting (Commanders and Chiefs) 1800 Planning Meeting (Planning) 1830 Plans Approval Meeting (Commanders and Chiefs) 37

38. Planning Meeting 38

39. Morning Briefing 39

40. Supply 40

41. Training Training 41

42. Surveillance 42

43. Epidemiological Assessments Proved Critical in Success • Surveillance Design for Commercial Flocks • Surveillance of Backyard Flocks • Surveillance of Wildbirds • Case Control Study • GIS Mapping and Spatial Analysis 43

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46. AI Case Control Study Preliminary Results Epidemiology Section Analysis team: Jennifer McQuiston Lindsey Garber 46

47. Risk Factors Assessed: Premises Characteristics - Security - Nearby lake/pond Farm Management - litter source - dead bird disposal Biosecurity - Visitor log - Showers - Disinfectant Footbaths Presence of Other Birds and Animals (wild, domestic) Recent Visitors Recent Travel 47

48. Case Control StudyAssessment of Risk Factors 48

49. Epidemiological Considerations • The source of this outbreak was never established. • The same strain of H7N2 has been seen in other small outbreaks in eastern states and live bird markets in the Northeast over a number of years. • A case-control study found flocks 7 times more likely to be infected if transporting dead birds to a rendering facility. • No evidence was found of airborne spread or spread associated with depopulation or disposal. • Disease was spread primarily by movement of people and equipment in a densely populated poultry rearing area. 49

50. Lessons Learned • The H7N2 strain that has circulated among Live Bird Markets of the Northeast and their supply and distribution channels continues to represent a serious threat to commercial poultry. • Control measures need to be taken to lessen the spread of this virus and further protect commercial flocks. • Rendering practices need to be reexamined with respect to the risk of disease spread. • During an outbreak biosecurity measures at the farm and plant level must be strengthened to prevent disease spread by people and equipment. 50