I don't watch the national television news broadcasts anymore because their reports lack credibility. I made an exception when I heard that a cow tested positive for bovine spongiform encephalopathy, also known as mad cow disease. I was curious to what extent it would be sensationalized. Note: I will refer to this disease by its proper name, BSE, and not by its sensational alias. Such was not the case with the report given by ABC News' "Good Morning America," which referred eight times to "mad cow" and none to BSE.
So I'd like to take a few moments to set the record straight and maybe the good folks at ABC News can learn a thing or two. BSE is a disease that affects the brain of cattle. It is caused by an infectious particle smaller than a virus called a prion and causes nervousness, incoordination, staggering and sometimes aggression in cattle. It is always fatal.
There are two recognized forms of BSE. The first is caused by the old practice of feeding rendered ruminant protein back to ruminants, like cattle. It was common, before it became illegal, to feed rendered meat and bone meal to cattle in small amounts as a protein source. This rendering process kills all bacteria and viruses. It reduces the activity of prions, but does not totally destroy them. It is now illegal to feed rendered ruminant protein back to cattle and other ruminants.
The second form of BSE is the type that was discovered last week in California. It is called atypical BSE because it is the result of a spontaneous mutation within this individual cow. She did not contract the disease from eating infected feed. Scientists are able to differentiate the two types through testing.
BSE is a human health concern because of the outbreak that occurred in the 1990s in England. Since then, 176 people in England have died from a disease called variant Creutzfeldt-Jakob disease, which is believed to result from repeated ingestion of infected meat products, specifically brain and spinal tissue. Incidence of both BSE and vCJD has decreased dramatically in England since the 1990s when the risks were recognized. There have been three cases of vCJD in the U.S., but all have occurred in people with a history of repeatedly eating infected meat products overseas.
Besides the ban on feeding rendered ruminant protein meal, there are other safeguards in place to prevent transmitting the infection to people. First, cattle over 30 months of age that are slaughtered must have the loin tissue discarded. This ensures that no spinal tissue, which may be infected, ends up in the meat. Second, there is a ban on the slaughter of downer cattle (cattle that can't stand) since this is the population of cattle with the highest risk of actually having BSE. And finally, there has been aggressive monitoring for the presence of BSE in cattle for the past 10 years. About 40,000 cows are tested yearly.
The cow that tested positive last week was not at a slaughterhouse but at a rendering plant. Her meat would have never entered the food supply. She was tested as part of the routine surveillance program that is ongoing. Despite all of the testing, there have been only four animals test positive for BSE since testing began 10 years ago. With the exception of the atypical case confirmed last week, the other positive cows were born before the feed ban. The safeguards are indeed working as this was the first case of BSE in the U.S. since 2006. No, Chicken Little, the sky is not falling after all.