New swine flu virus found by University of Hong Kong researchers
HKU team says strain is not expected to be a health threat if meat is well cooked
University of Hong Kong microbiologists have discovered a new strain of influenza virus in dead pigs at a slaughterhouse in Sheung Shui.
The team has named the virus porcine parainfluenza virus 1 (PPIV-1).
The swine virus is not expected to pose a significant health risk to humans as long as the pork they eat is well cooked.
But a top researcher behind the study, microbiologist Yuen Kwok-yung, warned it might mutate and jump from pigs to humans.
"The new virus is closely related to some human influenza viruses," Yuen said. "We should watch for possible cross-species transmission from pigs to humans, just as in the case of [human] swine influenza H1N1 and the Nipah virus."
The H1N1 virus triggered a global pandemic in 2009 when it jumped from pigs to humans. The Nipah virus, which is carried by fruit-eating bats, was discovered in Malaysia in 1999 after it spread from pigs to farmers and caused encephalitis and pneumonia.
The HKU researchers said the new virus was a paramyxovirus - a type known for being able to cross species barriers and cause severe epidemics in the new hosts.
Their study was published in the London-based this month.
The team detected the PPIV-1 in 12 of 386 pig carcasses collected from the slaughterhouse between 2008 and June last year.
The amount of the virus found in samples was high, they said.
The carcasses were discarded. Their origins are unknown, as the plant handles pigs from both local and mainland farms.
The city imports more than 3,000 live pigs from the mainland every day, and also slaughters a few hundred locally raised pigs daily, Food and Health Bureau data shows.
Yuen said normal consumption of the meat should not pose any danger to people, as long as they followed simple principles of food hygiene - to kill the virus by thorough cooking and to avoid mixing raw and cooked food.
"We believe this has been existing in pigs perhaps for quite some time as the gene sequences are already stabilised," he said. "It can spread readily by droplets and contact, especially among animals.
"If this virus came from other animals, we would expect rapid mutations still ongoing for adaptation to a new animal host."
The HKU team said it confirmed the PPIV-1 belonged to a group of viruses that affected the respiratory system.
The virus was likely to cause respiratory infection in pigs as it was present in the airways of the sick swine, Yuen said. But he added further study was needed to tell whether the pigs died of the virus.
The World Health Organisation has warned of a rising trend of new animal-related diseases.
Yuen called for more surveillance of pigs and other food and wild animals in Hong Kong, particularly for flu and other emerging viruses.
