Canadian officials announced Wednesday that multiple new H5 avian flu cases were found on two poultry farms where first such cases were reported last week in Canada's western-most province of British Columbia.
"Additional testing of these birds confirmed that a significant concentration of avian influenza virus was present on the farms," said Cornelius Kiley of the Canadian Food Inspection Agency.
The latest cases were discovered on two farms owned by the same poultry producer in the Fraser Valley, an agricultural swath of land stretching 100 km east of the port city of Vancouver.
Kiley said the H5 virus found in the first farm is a low-pathogenic strain, but it is still unclear whether the virus found on the second farm is a low or high pathogenic strain, adding that "we expect to know in the next day or two."
Officials said on Tuesday that the virus found on the second farm was perhaps harmless as no birds showed disease symptoms.
Some 55,000 ducks and 800 geese on the first farm had already been destroyed, and all 2,800 and 500 geese on the second farm will be culled by nightfall, Kiley said.
Birds in a five-km zone around the infected farms will remain under quarantine for the next 18 days.
The United States has banned poultry imports from British Columbia after the first case of H5 bird flu was reported in the province last week.
A total of 17 million birds were killed in the 2004 outbreak of bird flu in British Columbia.