Mad cow disease

• Article
• Comments ()
• Click-2-Listen
• Videos

By

According to the Center for Disease Control, 76 million Americans every year get food poisoning. If you do the math, that's about 1 in 4 of us every year. You know that "24-hour flu" you had this year? Well, you should know that there's no such thing as a 24-hour flu. You probably got food poisoning. From last year's Listeria and E. coli to a burgeoning antibiotic-resistant salmonella, in today's food safety lottery there's a 1 in 840 chance that we Americans will be hospitalized and a 1 in 55,000 chance that we will die from food-borne illness every year.

But E. coli? Easily destroyed by proper cooking. This new super-salmonella threat? Luckily, we still have big-gun antibiotics to kill it. Even bugs like Listeria are pretty wimpy pathogens. After millennia of humans eating the bodies and bodily fluids of other animals, you'd think Mother Nature could cook up a nastier microbe.

Well, let's use our imagination. What if there was something in our food supply that wasn't affected by cooking or antibiotics? Something new and undetectable, perhaps?Someultimate pathogen, practically indestructible, evading the immune system and maybe causing some, oh, invariably fatal neurodegenerative disease? Welcome to the world of bovine spongiform encephalopathy (BSE), or mad cow disease.

The pathogen thought responsible for this disease is not a virus, not a fungus, not a bacteria, but thought to be a prion -- an infectious protein. Because of their unique structure, prions are practically invulnerable. They can remain infectious for years in the soil. They are not adequately destroyed by cooking, canning, freezing, usable doses of radiation, digestive enzymes or stomach acid. Even heat sterilization, household bleach and formaldehyde sterilization have little or no effect. One study raised the disturbing question of whether even incineration could guarantee the inactivation of prions.

That study was performed by Paul Brown, medical director for the U.S. Public Health Service, who found prions could remain infectious even after exposure to temperatures over 1000 degrees Fahrenheit. That's hot enough to melt lead. Prions have been called the smallest, most lethal biological entities in the world.

It is perhaps not surprising that one cow in the United States has mad cow disease, given that certain cannibalistic practices of feeding slaughterhouse waste to livestock have been allowed to continue. What is surprising, given the inadequacy of our surveillance program, is that we found a case at all. Europe and Japan follow World Health Organization guidelines and test every downer cow for mad cow disease. By contrast, the United States has tested less than 2 percent of downers over the last decade. In 2003, we increased that testing, but only to about 10 percent.

Regardless of whether downer cows were tested or not, most of these animals -- cows too sick or injured to even walk -- have ended up on our dinner plates.

The Department of Agriculture (USDA) decision to finally remove downer cattle from the human food supply is a welcome departure from the past week's Pollyanna public relations, but it can only be effective in conjunction with a dramatic increase in surveillance testing. It seems the only reason we picked up the recent case was that the cow suffered a birthing injury.