Two pig samples taken two weeks ago at a slaughter house in Hong Kong has tested positive for the influenza A/H1N1 virus, local health authorities said Thursday.

It was the first cases of pig infections of the virus found in Hong Kong.

The Food and Health Bureau of the Hong Kong Special Administrative Region (HKSAR) government said the University of Hong Kong found the virus in two samples taken on Oct. 22 at the Sheung Shui slaughter house in a regular flu surveillance program.

"This surveillance program has been ongoing since 1999 and this is the first time that the human swine flu virus has been detected in pigs," the department said.

A spokesman for the department said the University of Hong Kong did not record the farm of origin of the pig samples concerned.

There had been no gene reassortment and the virus remains genetically similar to the influenza A/H1N1 flu viruses found in humans. Experts thought these findings indicate that the virus detected in pigs has been transmitted from humans, he said.

The risk of human contracting the virus has not increased, the spokesman added.

The spokesman said there was no cause for the public to be overly concerned and that it is safe to eat pork and pork products handled properly and cooked thoroughly.

Expert at the University of Hong Kong also indicated that there was no need to conduct testing for the virus on chilled and frozen pork.

Authorities has contacted all local pig farmers to remind them to stay vigilant, strictly implement biosecurity measures, maintain good farm and personal hygiene, and report any abnormality in farms immediately to health authorities.

"We have also informed the mainland authorities so that they can further step up the monitoring and inspection of the registered farms supplying live pigs to Hong Kong," the spokesman said.

Those involved in pig farming and slaughtering would be among the target groups when an influenza A/H1N1 vaccination program began, he added.