In Canada, 3 of 4 of the most recent bird flu outbreaks have occurred in British Columbia's Fraser Valley. There are theories, but no evidence, as to why the valley attracts the virus.
In the most recent avian influenza outbreak, 60,000 turkeys were culled. Tests indicate the virus has not spread to any other poultry producers within a 3-km quarantine zone.
The Canadian Food Inspection Agency (CFIA) has quarantined 7 premises outside the zone and an additional 2 inside, based on an analysis of the movement of people, products and equipment. In total, 36 premises are under quarantine.
Third major outbreak
This is the third bird flu outbreak in the Fraser Valley in recent years. Some scientists believe this to be related to the high-concentration of poultry operations in the valley and its location under the Pacific migratory flyway for wild birds that carry the disease.
History of AI in the region
Fraser Valley's first outbreak occurred in 2004 when an H7-type flu transformed into a highly contagious strain.
The second outbreak occurred in November 2005, when 2 duck farms were infected with the H5N2 strain of the virus.
In 2007, a highly pathogenic H7N3 strain was found in Saskatchewan on a farm that produced hatching eggs to produce broiler chickens.