WEDNESDAY June 11, 2008 (foodconsumer.org) -- Hong Kong announced Wednesday that the government planned to kill all chickens in the retail market because of an ongoing deadly birth flu outbreak.

The deadly H5N1 virus was detected last week in chickens at a stall in the Kowloon area and as a preventative measure, 2,700 animals were slaughtered to prevent the disease from spreading.

This week, the virus emerged at four markets in the New Territories and Hong Kong Island, prompting health officials to decide to cull all remaining live chidden in retail market, stalls and stores.

About 3,500 chickens in several hundreds of shops and stalls were reportedly waiting to be slaughtered. Officials said the measure is necessary.

Chickens slaughtered and early placed in supermarkets for sale are not affected.   In Hong Kong, residents have a tradition of buying live chicken and killing them hours before cooking.   The live chickens are the target that the government wants to control to prevent the virus.

The government also issued a 21-day-ban on imports of poultry from Mainland China.   But it did not ask local chicken farmers and wholesale distributors to do anything because they have been clear of the virus.

The H5n1 virus has killed at least 241 people, mostly in Asia since the virus was found in Hong Kong in 2003.   The virus is highly virulent, killing hosts quickly and making it difficult for the virus to spread from person to person.

Health officials are worried though that one mutation in the virus in the future could make the virus less lethal, but more contagious, causing a disastrous epidemic worldwide and killing tens of thousands if not more.

In 2007, Hong Kong health authorities registered 21 cases of H5N1 infections in 2007 and six people died in 1997 during an outbreak, Washington Post reported.