Officials Point Wild Birds For Hong Kong Bird Flu Outbreak

An outbreak of the deadly H5N1 bird flu virus at a Hong Kong farm last year which led to the slaughter of 90,000 chickens was likely spread by wild birds, an investigation found Thursday.

The December outbreak was the first discovered at a Hong Kong poultry farm in six years, and raised fears about the city's biosecurity measures and whether the deadly H5N1 virus had mutated.

"As with many epidemiological studies of this nature, it is difficult to determine the exact cause of the outbreak," said Thomas Sit, the head of the government's investigation team.

But he said the virus was "most likely to have been introduced to the farm by wild birds".

The dust and dirt near the entrance of one of the two affected chicken sheds could have been contaminated by droppings from infected wild birds and then blown into the shed area by a gust of wind, Sit said.

He added that they could not totally eliminate other sources, such as rodents or contaminated clothing of farm staff.

Sit said the farmer, who ran one of the city's major poultry farms, had been warned to improve biosecurity measures, but would not face further action.

Cheung Siu-hing, director of city's agriculture department, said authorities would strengthen biosecurity measures for all Hong Kong poultry farms by increasing the number of inspections and testing of blood samples.

"It is difficult, if not impossible, to say we can 100 percent prevent the spread of avian flu. That's why we have to learn from each incident. We can't afford to be complacent," she told reporters.