While new to Canada, the strain of tuberculosis bacteria which infected the Alberta cow at the centre of a bovine TB probe has been seen before in Mexico.
The Canadian Food Inspection Agency on Wednesday reported the strain of Mycobacterium bovis found in a southeastern Alberta cow is “closely related” to a strain originating from cattle in central Mexico in 1997.
The M. bovis pathogen from the infected cow is not the same as any strains previously detected in Canadian domestic animals, wildlife or people to date, CFIA said.
The bovine TB probe follows a notice in late September from the U.S. Department of Agriculture that a cow from Alberta had tested positive for the disease at a U.S. packing plant.
Removal and “humane destruction” of animals from the Alberta cow’s index herd continues, as do on-farm testing and tracing of potentially exposed animals, the agency said Wednesday.
While the index herd is the only one so far to turn up an infected cow, federal quarantines are in place on “approximately” 34 farms in Alberta and two in southwestern Saskatchewan as of Wednesday, CFIA said.
In Alberta, CFIA veterinarians and inspectors are contacting cattle producers in Newell County, around Brooks; the part of Cypress County north of Medicine Hat; the Municipal District of Acadia; and Special Areas No. 2 and No. 3, north of those municipalities.
In Saskatchewan, producers are being contacted in an area west of Highway 4 and south of the South Saskatchewan River.
A federally reportable livestock disease, bovine TB has been subject to a mandatory nationwide eradication program since 1923.
Canada is still considered officially free of bovine TB and would lose that status only if another separate Canadian case is confirmed within 48 months. Other TB-positive animals found in connection to the current probe would not be considered a separate case.
Canada’s most recent previous case of bovine TB turned up in a British Columbia beef cattle herd in May 2011.
Surveillance programs are also carried out in areas where livestock have been previously infected. Manitoba, where the disease is still found in wild deer and elk in and around Riding Mountain National Park, south of Dauphin, has been officially bovine TB-free since 2006.
The disease mainly affects ruminants, such as cattle, bison, elk, deer, goats and sheep, but can affect all types of mammals, including people — particularly those who have “extended close contact” with an infected animal while it’s alive.
Due to its “extremely low prevalence” in Canada, however, findings of bovine TB aren’t considered a public health threat. — AGCanada.com NetworkTagged bovine TB, CFIA, M. bovis, Mexico, tuberculosis