Bulletin of the World Health Organization

Best defence against avian flu is to fight the virus in Asia

The spread of avian flu to Africa and Europe has triggered panic as misconceptions abound over the nature of the threat this poses to human health.

Small child with ducks outside her house in Indonesia.
WHO/SEARO
Small child with ducks outside her house in Indonesia.

Farming practices, long-held lifestyle traditions and poverty-line economics all make recent outbreaks of avian flu in Asia a far bigger global public health threat than the westward spread of the disease into Europe’s poultry flocks.

For many rural Asian communities, backyard chickens and very small-scale poultry farms are part of the landscape. Children play in the same yard where the household’s flock scratch and where chickens that die are typically eaten in order not to waste a valuable source of protein.

Every infection of poultry has serious consequences for the farmers concerned. Flocks must be culled in a wide radius around the area of infection and every person in contact with infected live or dead poultry is at risk of contracting the disease.

Whilst most western Europeans would get no closer to poultry than peeling away the shrink-wrap cover on a pack of supermarket chicken breasts, in Asia most of the 67 confirmed deaths from the H5N1 avian flu virus have been attributed to direct contact with infected birds, such as the slaughter, defeathering, gutting and preparation of chicken and duck. All 130 known human cases of H5N1 have occurred in Asia.

In Asia, bird flu outbreaks have been reported over the last two years in Cambodia, China, Indonesia, Japan, Kazakhstan, Lao People’s Democratic Republic, Malaysia, Thailand and Viet Nam, the latter having borne the brunt of human infections with 42 WHO-confirmed deaths out of 92 cases since December 2003.

Many governments in the region are posed with a dilemma over how much scarce public funds should be poured into the fight against avian flu. Governments in the region have been making efforts to educate the population about preventive and surveillance measures, but misconceptions abound about the disease, both in poultry and humans.

Education campaigns in the affected countries are still not getting through to the individuals most at risk. Common misconceptions that owners of poultry have include the mistaken belief that it won’t happen to them, that chickens frequently fall sick and that this time is no more serious than any other time, according to Peter Cordingley, WHO’s spokesman for the Western Pacific Region, in Manila.

“Worse than any misconceptions, though, is the continuing ignorance in Asia, the fact that after two years people still know so little about risky practices. The latest case in Thailand confirmed by WHO was a woman who apparently cleaned out the muck from a poultry shed where her husband’s chickens had died mysteriously, and this was 50 km or so from Bangkok,” he said.

Dangerous misconceptions also exist at government level including “the belief early on by some governments that the outbreaks could be covered up and fixed, thus protecting the poultry industry without endangering public health and that vaccinating poultry is a quick, inexpensive and effective way of preventing or responding to outbreaks. Vaccination may stop the spread of the virus but does nothing to eliminate it. Culling is the only option, backed up, where appropriate, by vaccinating,” said Cordingley.

China, where H5N1 avian flu originated, is grappling with a resurgence of the disease among poultry and has con- firmed the first two human cases of infection with the virus on 17 November.

National government policy is at odds with what happens at the grassroots level because of patchy reporting at local level of outbreaks elsewhere in the country. Local level officials also fear incurring the ire of their superiors by being open about suspected or confirmed outbreaks and are reluctant to deal with the economic consequences of any decision to announce an outbreak and cull poultry.

“There has to be even greater public awareness. Even though bird flu is not new to China and has been widely reported over the last two years, news of every outbreak does not reach everyone and one of the biggest dangers is that this might lead to a sense of complacency,” said Roy Wadia, WHO’s spokesman in China. “But now that you’ve got confirmed human cases, people are taking more and more notice, and even getting scared.”

“The central government sees the overall problem in getting the right messages out, but it’s a big country with a way of life that has existed for thousands of years. People and animals live in very close quarters in rural areas, and backyard farmers move their flocks when they hear there’s a chicken cull under way. The other issue is one of compensation,” Wadia added.

There are also powerful and potentially harmful misconceptions about what medical options there are to prevent or treat human cases of either H5N1 avian flu or a reassorted avian flu pandemic strain.

“The public may perceive seasonal flu and avian flu to be the same and may also wrongly believe that influenza vaccine could prevent human beings from contracting avian flu,” said a spokeswoman for the Department of Health’s Centre of Health Protection in the Hong Kong Special Administrative Region.

Similarly, the antiviral drug oseltamovir (Tamiflu) is being erroneously touted as a magic bullet and there have been reports of individuals trying to secure supplies around the world, from London’s exclusive Harley Street medical clinics to private pharmacies that willingly sell most prescription-only drugs over the counter in Hong Kong Special Administrative Region.

“WHO does not recommend that individuals stockpile Tamiflu. WHO advises governments to stockpile this if they have the resources, but these are for a very specific public health purpose, as is WHO’s stockpile,” explained Maria Cheng, a spokeswoman at WHO in Geneva.

“These national and international stockpiles would be used in an attempt to stop a pandemic, or to at least mitigate its impact. There is no reason for healthy individuals to be taking Tamiflu and this might even encourage the development of a resistant strain, rendering the drug useless during a public health emergency,” Cheng added.

Public health experts say the only hope for avoiding a human flu pandemic — which may or may not involve a virus originating from birds — is to strengthen international cooperation.

This was the aim of a conference organized by the Food and Agriculture Organization, the World Organisation for Animal Health, the World Bank and WHO in Geneva from 7 to 9 November.

More than 600 public health experts and scientists from 100 countries agreed that there is an urgent need for financial and other resources for the countries which have already been affected by avian flu as well as for those which are most at risk.

Participants outlined a global action plan to control avian flu in animals and limit the threat of a human flu pandemic. To date, 36 Member States have reported to WHO that they have influenza pandemic preparedness plans in place.

Since May 2005, outbreaks of H5N1 disease have been reported among poultry in China, Kazakhstan, Romania, Russia and Turkey. Mongolia has reported outbreaks of H5N1 in wild, migratory birds and in October 2005, H5N1 was reported among migrating swans in Croatia. Experts fear the disease may spread further to south-western Europe and Africa, as birds migrate south for the winter.

But public health experts agree that Asia, where the only known human bird flu cases have occurred, is the region that poses the greatest immediate risk to global animal and human health.

“Europe is quite rightly taking measures to control the spread of the virus in poultry and to stock up on antiviral drugs in case of human infection, but the best defence for Europe or anywhere else against avian influenza is to help fight the virus in Asia,” said Cordingley.

Cordingley added: “If the situation is not brought under control in the backyard farms in this part of the world, the virus will continue to spread around the world year after year. Asia is ground zero and still represents the greatest threat to global public health.”

Jane Parry, Hong Kong SAR.

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“The public may perceive seasonal flu and avian flu to be the same and may also wrongly believe that influenza vaccine could prevent human beings from contracting avian flu.”
Spokeswoman for Hong Kong SAR Department of Health’s Centre of Health Protection.

“If the situation is not brought under control in the backyard farms in this part of the world, the virus will continue to spread around the world year after year. Asia is ground zero and still represents the greatest threat to global public health.”
Peter Cordingley, a spokesman for WHO’s Office for the Western Pacific Region based in Manila.