BSE surveillance and control should be stepped up in Canada 鈥渁nd beyond鈥�, says an international scientific panel asked to investigate after the first Canadian case was discovered in May.
The panel has told the Canadian government that to control the disease it must remove tissue such as brain and spinal cord from slaughtered cattle, and test many more high-risk cattle for BSE than it does at the moment. The government is willing to comply, but thinks the US should take similar measures. There has been no immediate response from the US.
When an eight-year-old cow in Alberta tested positive for BSE in May, it was North America鈥檚 first home-grown case. 麻豆传媒 said this meant that BSE could have spread throughout North America, and that the level of testing at the time could not rule this out (31 May, p 6).
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US officials disagreed (麻豆传媒, 21 June, p 30). But last week, Ulrich Kihm and Dagmar Heim of the Swiss Federal Veterinary Office, William Hueston of the University of Maryland, College Park, and Stuart MacDiarmid of New Zealand鈥檚 Massey University, who were asked by Ottawa to assess the situation, reached similar conclusions.
鈥淭he investigations have clearly established the need to address the risk that BSE is present in the Canadian herd and beyond,鈥� they conclude, recommending 鈥減olicy adjustments to address the changed North American dynamic鈥�, changes that should depend 鈥渙n the evolution of the BSE situation in Canada, and in North America as a whole鈥�.
They do not state outright that the presence of BSE in Canada means it is likely to be in the US as well. But Kihm, who led the panel, told journalists last month that, 鈥淚鈥檓 estimating that there will be other cases in this part of the world.鈥�
Until the discovery of the infected cow, the US was buying more than 80 per cent of Canada鈥檚 beef and cattle exports. Canadian investigators found that 25 cattle from the Saskatchewan herd that was probably the birthplace of the infected cow were exported to Montana between 1997 and 2002.
The panel suggests excluding cattle remains from all animal feed, not just ruminant feed, as the Canadians found farms where cattle might have eaten non-ruminant feed. It also recommends testing all 鈥渇allen鈥� and suspiciously ill cattle to assess the extent of infection. That would require a 17-fold increase in BSE testing across North America.
鈥淲e agree with these recommendations,鈥� says Canadian agriculture minister Lyle Vanclief. But he says new regulations would 鈥渞equire coordination, even harmonisation, with the United States鈥�. The US rejected calls from Congress to ban high-risk tissues in food and feed last year, and claims to be testing enough cattle to assess the risk.