Canada's Protocols for BSE Surveillance
BSE testing in Canada is in full accordance with the guidelines recommended by the World Organisation for Animal Health (OIE).
The samples collected target the highest risk cattle. This includes animals over 30 months of age that are dead, down, dying or diseased. In addition, any cattle that are exhibiting symptoms consistent with BSE must be reported to the Canadian Food Inspection Agency (CFIA). This targeted surveillance program is crucial to defining the level of BSE in Canada and to confirming the effectiveness of the measures in place to protect human and animal health from the disease. A robust surveillance program, with strong producer participation, gives domestic and international consumers confidence that Canada is taking responsible actions to monitor the health of the national herd.
The Government of Canada continues to work with provincial governments to support and encourage the participation of Canadian cattle producers in the surveillance program.
Preliminary Testing Procedures
In Canada, two rapid BSE screening tests are used for routine surveillance: the Prionics®-Check PrioStrip and the Bio-Rad TeSeE® ELISA.
Validations conducted by the European Food Safety Authority (EFSA) and the CFIA and agencies in other governments have found the tests to be 100% accurate for detecting BSE in cattle in later stages of the incubation period. Due to the high analytical sensitivity of the tests, there are rare instances in which samples not infected with BSE may produce an initial reaction, thus necessitating re-testing.
Second Round of Testing
Initially reactive samples are referred to as "non-negatives"and require that the same test be repeated in duplicate by the screening laboratory.
If the repeat tests are reactive, the sample is considered “inconclusive” for BSE, and the sample is forwarded to the CFIA laboratory in Lethbridge, Alberta, for confirmatory testing.
The rapid test on an inconclusive sample is repeated at the National BSE Reference Laboratory and if the test is again reactive, the sample is considered to be a BSE "suspect" and is subject to confirmatory testing. Even if this third rapid test is negative, a confirmatory test (immunohistochemistry or OIE Western Blot) is run for quality assurance purposes.
The immunohistochemistry (IHC) and the OIE Western Blot, also called the SAF Immunoblot, are internationally recognized confirmatory tests for BSE. The IHC is the principle confirmatory test used (gold standard) at the CFIA laboratory in Lethbridge, Alberta.
The OIE Western Blot test may be performed on the sample in addition to, or as an alternative to, the IHC test. It is always used on poor quality tissue samples when it may not be possible to conduct the IHC test, or on suspect samples where the IHC is negative.
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