WASHINGTON POST, April 19, 2001

Wonder Drugs at Risk

ANTIBIOTICS do their most visible saving work in sick humans, but a broader, hidden effect comes from their use in animals. Farm animals in the United States get abundant doses of antibiotics, with classically double-edged results: The drugs control the many infections that result from raising animals in tightly packed, super-efficient "factory farming" conditions, thus making meat cheaper and more plentiful. The constant dosing, however, fosters the rise of microbes resistant to those drugs. When humans pick up those same microbes from their meat in the form of food poisoning, as some inevitably do, the antibiotic won't cure their ailment.

Mounting evidence of the problem has led the Food and Drug Administration to take its first stab in many years at curtailing animal antibiotic use. Late last year it proposed to ban an antibiotic called enrofloxacin from its previously approved use in turkeys and chickens. Some of this drug's close relatives, called fluoroquinolones, are strong drugs, vitally needed to treat human ailments that don't respond to older antibiotics. One of the poultry drug's two suppliers, Abbott Laboratories, voluntarily withdrew it; the other, Bayer Corp., is contesting the proposed ban, saying there's insufficient evidence of a link between human resistance to the drug and its use in poultry. In fact, the evidence is good. It's drawn from a new federal monitoring system launched in 1996. When the drug was first approved for animals, evidence of infections resistant to that drug in humans was negligible. By 1998 resistance levels had jumped to 13 percent and by 1999 to nearly 18 percent. That's far faster than the gradual erosion of effectiveness that is common to antibiotics over time.

Environmental and medical groups have urged Bayer to change its mind, saying the protest process will otherwise drag on until it is too late to save the drug's effectiveness. But Bayer's drug is only a tiny piece of the antibiotic-resistance problem. The World Health Organization last year called on governments to ban the practice of giving healthy animals low doses of antibiotics to make them grow faster; the European Commission has a partial such ban, covering six common antibiotics that are also used in treating people. The EC left several others legal. Some U.S. groups have called for a similar ban, a move hotly opposed by growers. The FDA is also floating a possible rule to automatically halt animal use of a drug if resistance to it in humans rises above a set threshold.

Any antibiotic gradually loses its usefulness over time; overuse in human patients, not just in animals, plays a part. But the sheer volume of animal use and its unavoidable lack of precision, with drugs mixed in feed and whole flocks being dosed to cure a few sick chickens, makes that decay steeper. The FDA is right to begin reining it in.