# 4387
From Ironorehopper via his blog and FluTrackers we get this press release from the Hong Kong government about the discovery of a reassorted swine flu virus discovered last month in a pig from mainland China.
First the press release, then some discussion.
Swine Influenza Virus reassorted with Pandemic H1N1
February 26, 2010
Issued at HKT 22:37
The University of Hong Kong (HKU) had found in its regular influenza virus surveillance programme that one sample taken from a pig at the Sheung Shui Slaughterhouse on January 7 contained a virus which was essentially a swine influenza virus but had picked up a pandemic H1N1 gene by genetic reassortment. There is no cause for alarm for public health and pork remains safe for consumption. Government is closely monitoring developments and shall continue to keep the public informed.
This is the first time that reassortment of swine influenza virus with the pandemic H1N1 virus was found in the surveillance programme.
Prof Malik Peiris, the HKU expert in charge of the surveillance programme, considered that the findings of reassortment between the pandemic H1N1 virus and swine influenza virus was not totally unexpected. These events were likely occurring worldwide and its detection in Hong Kong was purely the consequence of intensive surveillance. Further tests are being conducted by HKU to determine if there are any particular characteristics of this strain.
A spokesman for the Centre for Food Safety (CFS) reaffirmed that the World Health Organization, World Organisation for Animal Health and Food and Agriculture Organization of the United Nations had stated that pork and pork products which were handled properly and thoroughly cooked were safe for human consumption. It is safe to eat pork and pork products that are cooked to an internal temperature of 70 degrees Celsius or above.
A spokesman for the Centre for Health Protection also said: “Laboratory surveillance on human specimens by the Department of Health (DH) has not detected similar viruses in humans.
“There is no sign that the virus is present in Hong Kong population at this time. The DH will maintain intensive surveillance of influenza in humans.
“Preliminary findings also show that the virus is sensitive to antiviral drug, oseltamivir. ”
The CFS spokesman said:“The sample was taken from a pig imported from the Mainland. We have 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.”
We talk about the reassortment of flu viruses in these pages with some regularity. Essentially, it occurs when two different flu viruses infect the same cell in a host at the same time, and swap gene segments.
The host can be a human, a bird, a pig, or any other mammal capable of being infected by multiple influenza viruses. How often this happens is unknown, but only rarely does it result in a new, viable virus that threatens humans.
Hong Kong is perhaps the most diligent region on earth for monitoring and examining flu viruses. Located adjacent to what many consider to be the `cradle of influenza’, mainland China, they are often the first to identify new and exotic strains.
We will eagerly await further details on exactly what swine virus, and what H1N1 gene segments, were involved. And what, if any, changes in pathogenicity or transmissibility may have occurred
For now this discovery of a reassorted virus is more of a scientific curiosity than a public health threat. There are no reports of any further spread of the virus at this time.
This is, however, an important reminder that the only constant with influenza viruses is that they constantly change. Whether it be via antigenic drift (small mutations) or antigenic shift (reassortment), virologists are quick to remind us.
Shift happens.
While the recent drop in influenza activity around the globe has been a welcome respite, we shouldn’t allow ourselves to be lulled into complacency.
There are no guarantees that we’ll have another 40 years before the next pandemic virus emerges.
