Outbreak Investigation Report on Avian Influenza in British Columbia, 2014
HPAI was identified in a broiler breeder chicken farm and a meat turkey farm in the Fraser Valley of British Columbia, Canada on December 1st, 2014. Subsequently, nine other commercial farms were infected with the same virus: six broiler breeders, two meat turkey, and one table egg layer. In addition, two non-commercial poultry flocks were also infected. All birds on infected farms were humanely destroyed and composted on-site.
The virus at the first 12 premises was identified as H5N2, a reassortant virus with the H5 from the highly pathogenic Eurasian H5N8 virus and the N2 from a North American virus. It was the first time a Eurasian HPAI H5 virus caused an outbreak of avian influenza in domestic poultry in North America. The 13th premises was a non-commercial flock infected with an H5N1 strain.
Movement restrictions were placed on 404 farms: 254 of these were located in the restricted zones and 150 were located in the infected zones, including the 11 infected commercial farms.
The CFIA undertook a complete outbreak investigation, including an epidemiological analysis. It was determined that:
For three commercial farms, the source of the virus was contact with infected farm birds and/or service personnel.
For five commercial farms and the non-commercial farms, the source of the virus was contact with wild birds.
For three commercial farms, the source of the virus is suspected to be localized/environmental spread.
Surveillance was completed on over 400 commercial farms during the outbreak period with over 8,300 samples collected testing negative for HPAI virus.
During the post-outbreak period, three months subsequent to the completion of cleaning and disinfection on all infected farms (March 3rd to June 3rd, 2015), post outbreak surveillance was undertaken. This period of enhanced surveillance for AI in BC met requirements to regain disease-free status.
On June 3rd, 2015, in accordance with Article 10.4.3.1 of the OIE Terrestrial Animal Health Code, the province of British Columbia regained its disease-free status with regard to Avian Influenza. The OIE was notified on June 8th, 2015.