Drug-Resistant Germs: Food for Thought

Too many antibiotics used in U.S. food supply, experts warn

SATURDAY, Nov. 16, 2002 (HealthDayNews) -- In the campaign to educate people about the danger of over-prescribing antibiotics, victories seem to be coming in small doses.

U.S. pediatricians are prescribing fewer antibiotics for common childhood respiratory infections than they were just a decade ago, a recent study says. This suggests that messages about drug-resistant germs are working.

At the same time, there's growing concern among some scientists and members of the medical community that people are ingesting too many antibiotics on a regular basis because of their widespread use in the food supply.

According to a recent report in the Journal of the American Medical Association, the number of antibiotic prescriptions for children under the age of 15 fell from 46 million in 1989 to 30 million in 2000. And the rate of prescriptions per 1,000 doctor visits dropped by nearly 30 percent during the same period.

Despite the drop, the rate is "still probably too high," says Linda F. McCaig, a statistician at the National Center for Health Statistics and lead author of the study.

For instance, the study found that many doctors continue to prescribe antibiotics such as penicillin and erythromycin for the common cold, a viral condition that doesn't respond to bacteria-killing drugs, McCaig says.

And experts estimate that as many as half of all prescriptions for childhood respiratory ailments are unnecessary.

OK, so you and your doctor agree that, from now on, no more antibiotics for trivial ailments. You won't ask for them and she won't prescribe them unless and until they're needed.

That should take care of your personal antibiotic resistance concerns -- unless you plan to eat food.

The Union of Concerned Scientists estimates that 70 percent of the antibiotics being used in the United States today are fed to healthy pigs, cows and chickens to promote growth and prevent disease. Of the 19 classes of antibiotics approved for use in animals, seven are commonly prescribed for human infections -- including Cipro, Bactrim and ampicillin.

As a result, there's a growing number of common food-borne bacteria strains -- such as listeria and E. coli -- that are becoming resistant to antibiotics.

"This is a blind risk," says Dr. Linda Tollefson, deputy director of the Center for Veterinary Medicine, part of the U.S. Food and Drug Administration. "People are getting resistant pathogens through food, and they don't even know it's happening. They are not in the hospital for some necessary treatment where they pick up a resistant pathogen. The risk that we're talking about is a crapshoot. It comes from eating food. And most people eat food."

Several types of drug-resistant bacteria are believed responsible for recent reports of drug-resistant infection.

For instance, an E. coli strain resistant to Bactrim led to an outbreak of urinary tract infections among women on college campuses across the United States last year. Although urinary tract infections aren't normally epidemic, the widespread incidence of the same bacteria led investigators to believe the source was food-borne, Tollefson says.

Then there's the Campylobacter bug, the most common bacterial cause of diarrheal illness in the United States. It infects 2 million Americans each year, usually through contact with raw chicken. Approximately 15 percent of the germ found in a random sample of Americans was of a strain resistant to the antibiotic Cipro. It was the same strain of the germ found in at least 10,000 cases of drug-resistant infection reported in 2001, Tollefson says.

In addition, one strain of the salmonella bacteria -- commonly transmitted to humans through foods such as chicken -- that causes typhoid fever is now resistant to tetracycline, ampicillin, streptomycin, sulfonamides and choloramphenicol, she says.

The list is long and growing, but since you obviously can't stop eating, what should you do?

Proper food handling and cooking can prevent some infections caused by food-borne bacteria. Hands, utensils and all surfaces that come into contact with raw meat or eggs should be washed thoroughly with soap and water. And all food from animal sources should be thoroughly cooked or pasteurized before being eaten, health experts say.

Vegetarians aren't off the hook either. Vegetables and fruits are not immune from exposure to food-borne bacteria, and should be washed thoroughly as well.

Ron Phillips, a spokesman for the Animal Health Institute, contends that the "use of antibiotics in animals is not the 'major driver' behind the resistance issue. What's amazing is that we've been using antibiotics in animals for 50 years, and, although we're still using the same compounds we began with, they are still effective."

Phillips and Tollefson took part in a public meeting sponsored by the Center for Veterinary Medicine last month that was aimed at completing a new categorization system for antibiotics used in animal production. The system is designed to discourage the use of antibiotics in animals that are important human food sources.

Even if adopted, the system would provide only guidance, not regulation.

"This is a long process," says Tollefson, adding that the decision to ban the use of such antibiotics is unlikely to lie with the U.S. Food and Drug Administration.

"I think it's taken several years to convince the food production industry the problem is real and that they have a role to play, but we don't have any means to make that societal judgment," she says. "That would have to be done by Congress."

So, while you're waiting for Congress to act, wash your knives, cutting boards, hands and tomatoes carefully.

What To Do

To learn more about antibiotic resistance and food-borne illness, visit the U.S. Centers for Disease Control and Prevention.

For an overview of drug-resistant bugs, check the U.S. Food and Drug Administration. For a primer on the proper use of antibiotics, see the American Medical Association.

SOURCES: Linda Tollefson, D.V.M., deputy director, Center for Veterinary Medicine, Rockville, Md.; Ron Phillips, spokesman, Animal Health Institute, Washington, D.C.; Linda F. McCaig, M.P.H., National Center for Health Statistics, Hyattsville, Md.
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