Ongoing surveillance of Canada’s wild bird population turned up no cases of highly pathogenic avian flu in 2007, according to the annual inter-agency wild bird influenza survey.
The 2007 survey included testing of wild birds along main Canadian migratory routes as well as in Iceland, where birds were sampled during their migration from Western Europe to the Canadian Arctic, according to a press release Thursday from the Canadian Food Inspection Agency (CFIA).
As expected, the 2007 survey found various avian flu subtypes, including both H5 and H7, but of low pathogenicity. Such “low-path” avian flu viruses commonly circulate in wild birds with little or no impact on the health of birds or people, CFIA said.
By OIE (World Organization for Animal Health) standards, Canada has been free of “high-path” bird flu since April, 90 days after the cleanup of an outbreak of avian flu of a “high-path” subtype, H7N3, on a poultry farm near Regina Beach, Sask.
That outbreak sickened and killed some birds on the farm last fall, leading to a complete cull and burial of the farm’s 50,000-odd birds, supervised by CFIA.
H7N3 affects birds but not people, and is not to be confused with H5N1, another “high-path” strain. H5N1 is blamed for the deaths of over 240 people overseas since late 2003, largely through direct contact with infected birds.
While “high-path” strains can be devastating on an affected commercial poultry farm, the concern of human health experts is that a strain such as H5N1 may mutate or combine with a human flu virus that could spread more easily among people, spurring a pandemic.
The annual inter-agency survey, which began in 2005, is a joint initiative between federal, provincial and territorial governments, the Canadian Co-operative Wildlife Health Centre (CCWHC) and Canada’s Avian Influenza Laboratory Network. The 2008 survey is now underway, CFIA said.