Hong Kong's Center for Food Safety (CFS) Friday announced that no A/H1N1 influenza viruses nor any reassortant of viruses were detected in samples from pigs taken during May to July.

The results reported were under a regular influenza virus surveillance program conducted by the University of Hong Kong at the Sheung Shui Slaughterhouse.

A spokesman for the CFS said that the CFS would continue to monitor reports of the program and make announcements on a regular basis.

"Results will be announced immediately if there are significant public health impacts such as gene re-assortment of viruses," he said, adding that given the wide transmission of the pandemic H1N1 virus in humans, detection of the virus in pigs would not be a surprise.

It was expected that positive findings may appear from time to time in the future, he said.

The CFS has been liaising closely with the Mainland authorities on any abnormal situation in the Mainland farms supplying live pigs to Hong Kong and farm inspection would be stepped up when necessary.

Under the surveillance program, the CFS has been helping the HKU researchers by collecting blood, tracheal and nasal swabs from pigs at the Sheung Shui Slaughterhouse twice a month.