News Release

Contact: Ben Richey
270-782-9798
brichey@animalagriculture.org

BSE: Just the Facts

BOWLING GREEN, Ky. –The debate on bovine spongiform encephalopathy (BSE) is seemingly endless, particularly with the number of parties involved in litigation and political positioning regarding BSE and international trade. Still, the science of BSE is the key factor in the decision-making process for industry leaders.

At its annual meeting in April, the National Institute for Animal Agriculture brought together two of the world’s experts on BSE, Dr. Will Hueston of the Center for Animal Health and Food Safety at the University of Minnesota and Dr. Brian Evans, Chief Veterinary Officer of Canada with the Canadian Food Inspection Agency.  The evening session, sponsored by the Canadian Consulate General in Minneapolis, gave attendees a candid discussion on the science of BSE.

“Although BSE has its origins over two decades ago, there has been significant advancement in our collective understanding of the measures necessary to effectively protect animal and public health which has been the foundation of our decision making,” said Evans in his presentation.

The implementation of these measures has resulted in a substantive decrease in BSE at the global level. At the height of the outbreak in the United Kingdom, there were over 102 cases per day. In 2004, there were less than 900 cases reported worldwide, and, as of the end of April, the numbers for 2005 are less than 150. Of the approximately 189,000 cases reported since 1986, 5,219 have been outside of the United Kingdom with a total of four in North America.

Evans added that every country's experience with BSE is in fact different based on the route and magnitude of exposure, the scope and duration of the mitigating measures in place and the level of compliance achieved. Canada and the United States have worked cooperatively in instituting a suite of measures including comparable feed bans introduced in 1997 to prevent the amplification and spread of the disease.

Hueston spoke on the epidemiology of BSE, and the importance of the feed bans in minimizing risks.  “Available evidence indicates that the incubation period of BSE is inversely proportional to exposure,” he said.  “This implies that with no feed controls, the level of BSE circulating in the feed increases and more cases are found more often and the cases are younger.  With the feed ban, as in North America, the BSE agent in feed decreases, as do cases and the age of diagnosed cattle is higher. (See fig. 1) Studies tell us that the larger the exposure, the shorter the incubation, while the smaller the exposure, the longer the incubation.” 

Hueston also discussed research on the distribution of the BSE agent in cattle tissues, noting that the distal ileum, brain and spinal cord contain the highest levels of the agent.  Additionally, research has shown that no evidence exists to date that the BSE agent is found in cattle muscle.  

Evans indicated that the North American BSE situation is unique, as consumer confidence has been maintained in the beef industry.  He added that this is unprecedented relative to other countries, and has resulted in a different environment for policy establishment. The North American experience allows a focus on progressive, considered, science-based, integrated measures.  

Though a number of trade barriers still exist for both the U.S. and Canada, Evans said that progress is being made in market recovery as more countries move to adopt import policies which reflect the science based standards for safe trade developed by the World Organization for Animal Health (OIE). While work remains to be done, governments are coming to understand the impacts of unwarranted restrictions, which serve to penalize countries for making appropriate investments in surveillance and transparent reporting.  Hueston added that the BSE risk has become partially fear driven, as opposed to evaluating the true danger that is considered among the scientific community. 

The trade issues have seen some progress recently, particularly with the Japanese moving forward with revised testing requirements, however the future still remains to be seen.  The reliance upon science will need to maintain a high-profile position with decisions on BSE issues. 

The National Institute for Animal Agriculture provides a forum for building consensus and advancing solutions for animal agriculture and provides continuing education and communication linkages to animal agriculture professionals.  NIAA is dedicated to programs that: work towards the eradication of diseases that pose risk to the health of animals, wildlife and humans; promote a safe and wholesome food supply for our nation and abroad; and promote best practices in environmental stewardship, animal health and well-being.  Visit us on the Internet at www.animalagriculture.org, or call 270-782-9798.

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