1. Asia Pacific Veterinary Information Services
Strategies for Controlling Animal Influenza and Implications for Human Health
Les Sims
Asia Pacific Veterinary Information Services

2. Background Animal influenza is not eradicable
Possible to eliminate certain strains of virus
Equine influenza in Australia
H5N1 HPAI from most infected countries

3. Background
Available control measures for influenza in animals are well described
How and when applied, more complex
Measures are used in combination
Not always used appropriately
Any measure applied inappropriately will hamper control
Control in animals usually reduces exposure of humans to animal influenza viruses

15. Vaccination

16. Surveillance and disease reporting systems
Underpin control programs
In many countries remain weak
Mandatory reporting of infection is only required for some subtypes in selected species (e.g. H5/H7 in poultry - NAI).
No international obligation to report cases of swine influenza (unless novel disease/strain)

17. Surveillance and disease reporting
Farmers usually have few incentives to report animal influenza
They can face significant disadvantages if they do
Consequences of surveillance

18. Influenza viruses in animals
Two broad ‘categories’ of animal influenza viruses
- those that countries choose to live with (but still subject to controls at individual farm level)
those they attempt to eliminate

19. Control measures Measures applied depend on:
- the virus subtype (e.g. H5, H7 (NAI) viruses versus H9 in poultry);
- the species involved (e.g. chicken versus wild bird)
- the country where infection occurs (e.g. Australia versus Vietnam)
Leads to variations in the objectives of animal influenza control programs from place to place

20. Objectives of different parties
Public health practitioner perspective/objective
Minimise exposure of humans to animal influenza viruses

21. Objectives of different parties
Commercial farmer perspective/objective
Control influenza until:
- it no longer has a significant effect on performance or profits
farmers are sure they will retain key markets (including export markets)
Legitimate concerns about effects on sales
Some influenza viruses are subject to state and industry supported ‘eradication’ campaigns when they occur

22. Objectives of different parties
Smallholder/household producer perspective
Low input systems for food security/income diversity
Some driven by poverty
Influenza only considered a problem if it causes severe losses (due to disease or to the control measures applied, including losses of markets)

23. Areas of concern – human health
1. The difficulties encountered in eliminating Influenza A(H5N1) viruses from poultry in countries where infection is endemic
- Risk to humans from influenza A(H5N1) will persist for at least the next 5 to 10 years

24. 2 6
1996
2007
2003
2003

25. Areas of concern - countries with endemic infection
Why have these countries remained endemically infected ?
Three main factors
Nature of the production and marketing systems

26. Reproduced from FAO/USAID Atlas of poultry production

27. Grazing ducks (75% of global ducks in China and Vietnam – many free range)

28. Poorly regulated markets – this one has been closed

30. Areas of concern - countries with endemic infection
ii) Quality of veterinary and animal production services
iii) Commitment from public and private sector to virus elimination (not just containment)

31. Areas of concern – human health
2. Large scale animal influenza vaccination programs
Need to balance benefits versus concerns
Need to understand objectives of vaccination program
- effects of vaccination on antigenic characteristics of viruses
autogenous vaccines (especially in pig production)
effects of ‘silent’ infection (need for modified surveillance and reporting signals)
Need better(user friendly) vaccines

32. Areas of concern – human health
3. The trend towards larger industrialized production units
Not a recommendation of international agencies for influenza control
Farm workers as a bridge to communities
Potential for looser ties to government (in house testing)
Potential for negative effects on poor

33. Areas of concern - trend towards larger units
50% increase in human population in next 40 years – predominantly urban
Pig and poultry production expected to increase dramatically
Will provide opportunities for emergence of novel influenza viruses

34. Areas of concern – human health
4. Globalization and increased trade in livestock products
Most introductions of avian influenza by trade in live poultry probably occur across land borders
Most international trade in live poultry is in day old chicks (virus not vertically transmitted)

35. “If a pig coughs in Mexico the world should know about it”
Moves to improve surveillance and early identification and containment of potential human pandemic influenza viruses are laudable
Likely to fall short of expectations

36. Could we have stopped the 2009 pandemic with early detection?
If the 2009 influenza A(H1N1) pandemic virus had been detected in pigs in January 2009 what measures would have been implemented?
Not the first North American-Eurasian reassortant pig virus
Few characteristics to suggest it would be readily transmissible between humans
Low probability that such a virus would be detected when it first emerged (i.e. before spreading to other sites)

37. Pre-emptive action Clear criteria are needed on:
- when action will be taken to contain/eliminate newly emerged strains of interest in animals;
- the measures that will be used; and
the support that will be provided to producers and countries affected by the measures.

38. Pre-emptive action
To improve success, actions proposed should not disadvantage transparent countries or alienate farming communities
Communities need to understand and see the benefits in making changes and of being involved in surveillance – no simple solution
Close associations between humans and animals is not restricted to developing countries

40. Thank you for your attention

41. Acknowledgements
I have been privileged to work in Asia for the past 17 years.
The observations and views in this presentation are personal but developed while working for a number of organizations, including the Government of Hong Kong, FAO, the World Bank, IDRC and PATH.
I wish to thank my many colleagues globally, and especially in Hong Kong, Vietnam, Cambodia, Mainland China and Thailand, who have worked with me, shared their expertise and helped to shape my views on animal influenza.
I would like to thank the Influenza Options team for inviting me to speak at the conference.