OTTAWA, August 24, 2006 Investigators from the Canadian Food Inspection Agency (CFIA)
have concluded their
epidemiological investigation of the 50-month-old dairy cow from
Alberta diagnosed with bovine spongiform encephalopathy (BSE) on July 13, 2006. No part of
the animals carcass entered the human food or animal feed systems.
The animal died of causes unrelated to BSE and would likely have lived for an
additional four to six months before the onset of BSE-related clinical signs. This age
range is not significantly different from that of previous Canadian cases and indicates
exposure to only a very low dose of BSE infectivity. The detection of this case at the
earliest possible moment demonstrates the highly sensitive nature of Canadas
national BSE surveillance program, which targets cattle from the highest risk populations
and has tested more than 117,000 animals since 2003.
Because the animal was exposed to BSE after the 1997 implementation of Canadas
feed ban, the CFIA placed priority on conducting a comprehensive review of all potential
routes of BSE exposure. In general, investigators observed good levels of compliance with
the feed ban at the farm, retail and manufacturing levels. A particular incident was
documented in one commercial feed facility that may have permitted the contamination of a
single batch of cattle feed with prohibited material. The entire batch of feed was shipped
to the BSE-positive
animal's farm. While the investigation looked at all possible routes of
exposure, this particular batch of feed is the most probable source of
infection. The CFIA
has launched an enforcement investigation.
In 2005, Canadian and American officials reviewed and confirmed the effectiveness of
Canadas feed ban. In addition, the surveillance program continues to indicate that
the feed ban has prevented the level of infectivity in Canada from increasing.
Nonetheless, the extremely small infective dose of BSE means that even very limited
opportunities for contamination may permit periodic cases. The emergence of such cases is
common to almost every country reporting the disease. The enhanced feed ban announced on
June 26, 2006, will further limit potential BSE spread. Potentially harmful cattle
tissues-which are currently prohibited in feeds for cattle, sheep, goats and other
ruminants-are being banned from all animal feeds. This action prevents more than 99% of
potential infectivity from entering the top of the animal feed chain, thereby addressing
any downstream contamination that could occur.
The animal component of the investigation traced 172 cattle born or raised on the same
premises as the positive animal. Using Canadas cattle identification system, the CFIA
fully accounted for all but eight of these animals and located 38 live cattle. Most of
these animals have been humanely euthanized and incinerated. The remainder are under
quarantine and will be destroyed once calving or harvesting of genetic material, as
allowed by the World Organization for Animal Health (OIE), is complete.
A complete
summary of the investigation is available on the CFIAs website.
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For information:
CFIA Media relations: (613) 228-6682
Report on the
Investigation of the Seventh Case of BSE in Canada
Main Page - BSE in
North America
