Britain to cull chickens as bird flu strain found

LONDON, Apr 27 (Reuters) Britain is to start culling 35,000 birds on a poultry farm in the east of the country today after a strain of bird flu was detected in chickens.

Preliminary tests showed the virus was likely to be an H7 strain of bird flu, not the lethal H5N1 avian virus that has infected 204 people and killed 113 since 2003.

''Tests are still ongoing to find out the exact strain of the virus,'' a spokesman for the Department for the Environment, Food and Rural Affairs (DEFRA) told Reuters.

He said all the birds on the farm near Norwich, an area which is home to some of Europe's biggest poultry farms, would be killed as soon as possible as a precautionary measure.

Britain has been on high alert for bird flu since it discovered the lethal H5N1 virus in a wild bird in Scotland earlier this month.

The swan was the only wild bird found in Britain so far to have the H5N1 virus, which has spread from Asia to Europe, the Middle East and Africa, and led to the death and culling of 200 million birds since late 2003.

Scientists fear bird flu could become highly dangerous to humans if the virus mutates into a form easily passed on from one person to another.

British animal health experts had not yet decided whether to impose an exclusion zone around the poultry farm near the market town of Dereham to prevent the spread of the virus.

''That has yet to be decided until we know the exact strain of the disease,'' the DEFRA spokesman said.

Results of the tests will determine whether it is highly pathogenic or low pathogenic.

Freda Scott-Park, the president of the British Veterinary Association, said the avian flu strain did not pose a threat to public health. But she said poultry workers and veterinarians looking after the farm would have to take extra precautions.

''There is absolutely no risk to health,'' she said.

An outbreak of the H7N7 bird flu strain in the Netherlands in 2003 led to the culling of 30 million birds, about a third of all Dutch poultry at a cost of hundreds of millions of euros.

A veterinarian working on an infected Dutch farm caught the disease and later died of pneumonia. It infected more than 80 people in total.

Both highly pathogenic and low pathogenic avian influenzas can infect humans but rarely do so. H5N1 is the bird flu strain which poses the biggest threat to public health, although cases of human infection remain relatively infrequent.

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