But are these measures enough?
Concerns about these new measures center on the surveillance program. First, how long will it take the USDA to expand its testing? Second, will even this expanded testing be sufficient? Some scientists and consumer advocates propose adopting the policy of the European Union, which is to test all cattle over 30 months of age, since this age group can harbor BSE without being ill.
Other congressional proposals include ban-ning all high-risk meat products from all animal feeds and cosmetics, and creating a prion disease task force to coordinate surveillance and research for all prion diseases. Unfortunately, because we have been testing so few cattle for BSE, we don’t really know if there are more infected cattle in our food system. Interestingly, in Japan, where all cattle are tested for BSE after slaughter, 10 more infected animals were discovered, most of which lacked the characteristics that would put them at high risk.3
To date, the beef industry has supported the changes already put into effect, but not the additional ones noted above. Ironically, a number of small, upscale slaughterhouses have proposed testing all cattle they slaughter (mostly under 30 months old) so they may resume sales to Japan. The USDA has turned down their requests for the chemical reagents to run the BSE tests (the agency controls the sale of these kits), citing its concern that testing all cattle would give the impression it is necessary for the entire US herd—a proposition the USDA and many scientists believe is unnecessary. Thus, the controversy over BSE surveillance has now become an economic, political, and scientific issue.
What to advise patients
The risk of contracting vCJD from eating contaminated beef is extremely small.4
There has yet to be a case of BSE found in any native-born US cattle.
There is no association between BSE and milk or milk products.
If traveling to countries where BSE is endem-ic—ie, UK and Portugal—patients may avoid beef altogether or limit consumption to whole cuts, not ground beef or sausage.5
Avoid bovine-derived nutritional supplements, especially those containing bovine pitu-itary, thyroid, adrenal, thymus, or other organ tissue.
Avoid products containing bovine meat or bone meal, such as some types of garden fertilizers.
Deer and elk can develop chronic wasting disease (CWD), another form of TSE. States that have recorded CWD cases include Colorado, Illinois, Wisconsin, and Wyoming. CWD is not known to cause disease in humans, but the risk to hunters and those who eat the meat is unknown. Physicians may want to advise hunters to have deer and elk hunted in CWD areas tested and only CWD negative animals processed for meat. Guidelines for field dressing deer and elk to prevent possible contamination of meat are available at state Departments of Natural Resources.
Investigating suspected disease
Physicians who suspect a patient may have vCJD or CJD, or that a patient has died of such disease, should advocate for brain biopsy or autopsy. The National Prion Disease Pathology Surveillance Center at Case Western University (funded by the Centers for Disease Control and Prevention) provides diagnostic services free of charge to physicians and health departments (available at www.cjdsurveillance.com).
The first US case
Federal agencies, Congress, and the public became more aware of BSE on December 23, 2003, when the US Department of Agriculture (USDA) diagnosed the disease in a dairy cow in Washington state.1 The cow, traced to a herd originating in Canada, was 6.5 years old and had been slaughtered on December 9. Whether the cow was a “downer” (nonambulatory) is still under investigation. Downer cows are automatically tested; however, it is possible this cow was tested as part of a routine surveillance system rather than because it was at high risk of disease. Regardless, the carcass was released for use as food while tissues considered more risky for BSE transmission (brain, spinal cord, and small intestine) were kept from the human food supply.
After the case was diagnosed, the USDA recalled all meat from cattle slaughtered at that plant the same day. Unfortunately about 30,000 pounds of potentially contaminated meat was never recovered and ended up on consumers’ plates.
Corresponding author
Eric Henley, MD, MPH, Co-Editor, Practice Alert, 1601 Parkview Avenue, Rockford, IL 61107. E-mail: ehenley@eic.edu.