Canada continues bovine TB investigation

After finding bovine tuberculosis in late September, several farms in Alberta and Saskatchewan are under movement controls.

In late September, the U.S. Department of Agriculture notified the Canadian Food Inspection Agency (CFIA) that a case of bovine tuberculosis (TB) was detected in a cow from Alberta when it was slaughtered in the U.S.

CFIA said a team of investigators was immediately mobilized to manage the agency's initial investigation and response to the finding. On Oct. 24, the operations center in Calgary, Alb., was fully activated. CFIA's emergency response plans are scalable depending on the nature of the event. Additional communication and logistical support was added when the National Emergency Operations Centre was activated.

According to a recent update from CFIA, there are currently 34 farms in Alberta and two farms in Saskatchewan under CFIA quarantine and movement controls.

To date, there are six confirmed cases of bovine TB, including the index cow that was confirmed to have the disease when it was slaughtered in the U.S. All confirmed cases are from the one infected herd located on three separate premises in Alberta. All of the cattle from the herd are in the process of being removed from the premises and humanely destroyed.

While there are no confirmed cases of bovine TB in Saskatchewan, CFIA said the animals on the quarantined farms in that province have been in contact with the infected herd and are, therefore, subject to movement controls.

Of the animals CFIA has tested to date, 52 showed a response to initial testing and then received a postmortem examination. The postmortem revealed that 12 of these animals had gross lesions compatible with bovine TB. The tissue samples from these animals were sent to the lab for examination. Laboratory results confirmed that the lesions seen in five of the animals are consistent with bovine TB. Five animals had polymerase chain reaction results that were positive for Mycobacterium tuberculosis complex, presumptive Mycobacterium bovis.

These positive test results indicate that transmission among animals has occurred, and CFIA is currently conducting a risk assessment to determine how these results affect the investigation and whether or not additional herds may be declared infected.

The increase in the number of infected animals has no effect on food safety. This is because all animals are examined for signs of disease at slaughter. Any animal that shows signs of disease, like the lesions associated with bovine TB, is condemned, and meat from that animal will not be sold for human consumption. The practice of conducting a postmortem examination on each animal slaughtered has been standard in Canada since the 1930s and is not a new measure applied in light of the recently discovered situation in Alberta.

To date, there have been no impacts on trade.

CFIA said it will update its website on a regular basis as new information regarding the investigation becomes available.

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