The farm in Kam Tin, Yuen Long, has about 1,200 pigs, and all pigs were found to be healthy during recent inspections. The farm's owner and workers have no flu-like symptoms. The department has informed the Centre for Health Protection for necessary follow up action.

A batch of about 100 pigs, including the one whose sample tested positive for the flu, was stopped from being sent for slaughtering. The department has been collecting more samples, from this farm and other local pig farms, and all other results so far are negative.

The department is reminding local pig farmers to remain vigilant, strictly implement biosecurity measures, and maintain good farm and personal hygiene. They should report any abnormality immediately. If pig farm owners or their workers feel unwell, they should seek medical attention.

Those involved in pig farming and slaughtering are among the target groups for the flu vaccination programme that will begin on 21 December.

The department noted that the World Health Organisation, World Organisation for Animal Health and Codex Alimentarius Commission have stated that pork and pork products which were handled properly and cooked thoroughly were not a source of human swine flu infection. The virus is killed under a temperature of 70 degrees Celsius or above.

Meanwhile, Secretary for Food & Health Dr York Chow has assured consumers that although the H1N1 virus has been found in a local pig, other pigs at the farm will not be sold until their tests are cleared.

"We have also advised that the pigs from this farm are not sent to the abattoir until we have cleared the test to make sure it is negative [for the virus]," Dr Chow told reporters today, adding pork consumption is safe.

He said the pig may have been infected either by the workers who might have carried the virus onto the farm or other pigs, usually breeding pigs, imported from the Mainland which might also have carried the virus.

Dr Chow urged pig farmers to be vaccinated when the inoculation programme starts, noting the consent form is routine to ensure the person receiving the jab knows about the possible side effects.

"It is important for us to let the public know what we are advising and the risks they are facing," Dr Chow said, noting at least 50 million people worldwide have received the vaccine safely.