One pig sample taken at the Sheung Shui Slaughterhouse on January 7 contains essentially a swine influenza virus that had picked up an H1N1 gene, the University of Hong Kong has found.

This is the first time that a reassortment of swine flu virus with the pandemic H1N1 virus was found in its surveillance programme.

There is no cause for alarm for public health, and pork remains safe for consumption, the Centre for Health Protection said. The Government is monitoring developments and will keep the public informed.

Prof Malik Peiris, the HKU expert in charge of the surveillance programme, does not consider the findings totally unexpected.

These events are likely occurring worldwide and its detection in Hong Kong is purely the consequence of intensive surveillance. The university is conducting more tests to determine if there are any particular characteristics of this strain.

The Department of Health's laboratory surveillance of human specimens has not detected similar viruses in people.

There is no sign that the virus is present in the Hong Kong population at this time. The department will maintain surveillance of flu in people. Preliminary findings also show that the virus is sensitive to the antiviral drug oseltamivir.