# 6144
Every few months we get an update from Hong Kong’s swine surveillance program – conducted by the University of Hong Kong - that looks for influenza viruses in pigs arriving at Sheung Shui for slaughter.
Several influenza viruses commonly circulate in swine (primarily H1N1, H1N2, H3N2), but what these researchers are looking for are signs of new, or novel strains.
Of 1,500 samples tested between October 2011 and January 2012, 27 were found to be reassortments of standard swine flu viruses with the 2009 H1N1 virus.
Reassortment happens when two different influenza viruses co-infect the same host, swap genetic material, and produce a hybrid virus.
Two of the 27 were reassorted H3N2 viruses, while 25 were H1N2 strains.
While neither particularly alarming or surprising, these virus detections are further evidence of the ongoing evolution of influenza viruses in swine populations.
For more on the potential threat posed by such reassortant viruses, I would invite you revisit my 2010 essay called:
The (Swine) Influenza Reassortment Puzzle
This from the Hong Kong Government.
FEHD releases latest results of influenza virus surveillance in pigs
The Centre for Food Safety (CFS) of the Food and Environmental Hygiene Department (FEHD) today (February 14) announced the latest round of results of the regular influenza virus surveillance programme for pigs at the Sheung Shui Slaughterhouse conducted by the University of Hong Kong (HKU).
Among some 1,500 samples collected and tested from mid-October 2011 to January 2012, one sample tested positive for the human swine influenza virus (pandemic H1N1).
A total of 27 samples were found to contain viruses that were essentially swine influenza viruses but had picked up some genes of human swine influenza virus. Among them, two samples were detected with a swine influenza, H3N2, while the remaining 25 samples had H1N2. Swine influenza viruses carrying the genes of the human swine influenza virus were also found in the last two rounds of the surveillance programme (i.e. for May to July and August to October last year).
According to Professor JSM Peiris, the HKU expert in charge of the surveillance programme, given the wide transmission of the pandemic H1N1 virus in humans, detection of the virus in pigs is no surprise. Positive findings might continue to appear from time to time in future.
"There have been similar reports from many parts of the world showing that swine influenza viruses carried the genes of the human swine influenza virus. Such viruses are unlikely to pose any major human health risk or cause problems in food safety," Professor Peiris added.
Under the regular influenza virus surveillance programme for pigs, the CFS has been helping HKU researchers to collect blood and tracheal and nasal swabs from pigs at the Sheung Shui Slaughterhouse twice a month to monitor influenza virus activity in pigs.
"The CFS will continue to monitor reports of the HKU surveillance programme and make announcements on a regular basis. Results will be announced immediately if there are significant public health impacts," a CFS spokesman said.
