Dec 7, 2005 (CIDRAP News) – Although thorough cooking ensures that chicken and other poultry are safe to eat, birds from flocks infected with H5N1 avian influenza should be kept out of the food supply, international health and agriculture authorities said this week.
The United Nations Food and Agriculture Organization (FAO) and the World Health Organization (WHO) warned against eating raw poultry parts or raw eggs from areas with avian flu outbreaks in poultry, as well as eating infected birds or using them for animal feed.
The agencies said they wanted to clarify food safety issues raised by the avian flu crisis. The statement released this week is an abridged version of a bulletin issued in November through the International Food Safety Authorities Network.
"In areas where there is no bird flu outbreak in poultry, there is no risk that consumers will be exposed to the virus via the handling or consumption of poultry and poultry products," the statement said.
Cooking to achieve a temperature of 70˚C throughout all parts of a bird, so that no part remains raw or red, will kill any H5N1 virus present, the agencies said. This will prevent infection from an infected bird that is mistakenly allowed into the food chain.
"To date, there is no epidemiological evidence that people have become infected after eating contaminated poultry meat that has been properly cooked," the statement said.
Many of the people who have contracted avian flu were infected when slaughtering or handling diseased or dead birds before cooking, authorities said. Slaughtering poses the greatest risk of infection.
Most strains of avian flu viruses are found mainly in the respiratory and gastrointestinal tracts of infected birds, not in the meat, the agencies said. But highly pathogenic viruses like H5N1 make their way into almost all parts of the bird, including the meat.
Infected poultry excrete the virus in their secretions and feces, and people may be exposed by inhaling dust or touching contaminated surfaces. The virus can survive in feces for at least 35 days at low temperatures (4˚C) and for 6 days at higher temperatures (37˚C). It can survive on surfaces for several weeks, and it is not killed by refrigeration or freezing.
It's not always possible to distinguish infected and uninfected birds in outbreak areas, since ducks may harbor the virus without looking sick, officials said. This increases the importance of using preventive measures.
Although public education campaigns about avian flu have reached rural people in affected countries, some continue to eat infected birds, the agencies said. They warned, "The practice of slaughtering and eating of infected birds, whether diseased or already dead, must be stopped. These birds should also not be used for animal feed."
The risk of getting infected by handling a bird produced through an industrialized slaughtering and processing chain is considered very low, even in countries with current outbreaks, authorities said.
They also said eating vaccinated poultry poses no particular risk for consumers, provided the vaccination program follows proper standards and includes appropriate monitoring.
Eggs from infected birds can be contaminated on both the inside and the shell, according to the agencies. Although sick birds normally stop laying eggs, eggs laid in the early phase of the disease could be contaminated. Proper cooking kills the virus, as does pasteurization used by industry for liquid egg products.
Eggs from areas with outbreaks in poultry should not be consumed raw or partially cooked (with runny yolk), FAO/WHO say. But so far there is no epidemiologic evidence that people have been infected with avian flu by eating eggs or egg products.
FAO/WHO news release