Chicken and other poultry carry no risk of passing on bird flu to people if cooked properly, according to a recent joint statement by world health leaders.

The United Nations Food and Agriculture Organization (FAO) and the World Health Organization (WHO) offered the advice to national food safety authorities amid growing concern over the avian influenza outbreak.

It warned birds from flocks carrying with the disease should not be allowed to enter the food chain.

Bird flu has infected millions of poultry in the world this year and at least 133 people, including 69 deaths.

In areas without outbreaks of avian influenza in poultry, there is no risk that consumers could be exposed to the virus via the handling or consumption of poultry or related products, the statement said.

In areas where poultry has been infected, consumers are being advised to cook meat such as chicken, duck, goose, turkey and guinea-fowl at or above 70 C.

Health leaders said the higher temperatures would kill any traces of the H5N1 virus and make the meat safe to eat.

To date, there is no evidence that people have become infected after eating contaminated poultry meat that has been properly cooked.

Infection channels

From the information currently available, a large number of confirmed human cases of bird flu came during the home slaughtering and subsequent handling of diseased or dead birds prior to cooking.

FAO and WHO emphasized that slaughtering infected birds poses the greatest risk of the virus being passed on to humans.

Most strains of avian influenza are mainly found in the respiratory and gastrointestinal tracts of infected birds, and not in the meat itself.

However, highly pathogenic viruses, such as the H5N1 strain, spread to virtually all parts of an infected bird.

Infected poultry also excrete the virus in their faeces.

Exposure to humans, such as slaughterers, might also occur when the virus is inhaled through dust and contact with surfaces contaminated with the virus.

People are being warned that in areas where birds are often sold alive, the practices of home slaughtering, defeathering, and eviscerating can increase the exposure to potentially contaminated parts of the poultry.

It is not always possible to differentiate infected and non-infected birds in areas that have outbreaks.

Some, such as domestic ducks, may harbour the virus without displaying symptoms.

People are being urged to be fully informed about preventive measures, including the use of protective equipment.

Good hygienic practices

The FAO and WHO are urging the practice of slaughtering and eating infected birds in households, whether diseased or already dead, to be stopped.

The birds should also not be used for animal feed.

Even in areas or countries suffering outbreaks, the likelihood of infected poultry entering an industrialized slaughtering and processing chain, and eventually being marketed and handled by consumers or restaurant workers, is considered to be very low, FAO and WHO said.

They added that good hygienic practices, such as high cooking temperatures, will further contribute to the safety of cooked poultry meat.

Proper vaccination of domestic poultry is considered to be a useful tool by health leaders as part of an overall integrated strategy for the control of highly pathogenic avian influenza strains.

But it must be implemented in accordance with existing standards and procedures for vaccination, they added,

With appropriate monitoring programs in place, vaccinated poultry can enter the food chain without particular risk for the consumer.

Highly pathogenic strains of the avian influenza virus can also be found inside and on the surface of eggs laid by infected birds.

Although sick birds will normally stop producing eggs, eggs laid in the early phase of the disease could contain viruses in the egg-white and yolk as well as on the surface of the shell.

Proper cooking, however, inactivates the virus present inside the eggs.

Pasteurization used by industry for liquid egg products is also effective in inactivating it.

But eggs from areas with outbreaks in poultry should not be consumed raw or only partially cooked, such as with runny yolk, FAO and WHO said.

However, as with meat, there is no evidence to date to suggest that people have been infected with bird flu by eating eggs or egg products if cooked properly.

Recommended practices

Recommended good hygienic practices that have been issued to reduce exposure to the virus in areas with outbreaks in poultry are:

No birds from flocks with disease should enter the food chain.

Do not eat raw poultry parts, including raw blood, or raw eggs in or from areas with outbreaks in poultry.

Separate raw meat from cooked or ready-to-eat foods to avoid contamination.

Do not use the same chopping board or knife.

Do not handle both raw and cooked foods without washing your hands in between and do not place cooked meat back on the same plate or surface it was on prior to cooking.

Do not use raw or soft-boiled eggs in food preparations that will not be heat treated or cooked.

Wash your hands and keep them clean. After handling frozen or thawed raw poultry or eggs, wash your hands thoroughly with soap.

Wash and disinfect all surfaces and utensils that have been in contact with the raw meat.

Cook thoroughly: Thorough cooking of poultry meat will inactivate the virus.

Either ensure that the poultry meat reaches 70 C at the centre of the product ("piping" hot) or that the meat is not pink in any part.

Egg yolks should not liquid.

(China Daily December 9, 2005)