THE BACTERIA BATTLE

The parent of a child with an ear infection is likely to get a quick lesson in the history of antibiotics: Amoxicillin once was thought to be highly effective against these earaches, but its widespread use and overuse have allowed bacteria to adapt and resist the drug. Many more and many more expensive antibiotics are now needed to treat the range of bacteria that cause ear infections.

A well-organized and well-supported group called Keep Antibiotics Working says the overuse of antibiotics in livestock causes similar problems. It wants Congress to limit their use to animals that actually are sick, rather than allowing them to be routinely administered along with feed. The restrictions are backed by a wide range of groups, including the Maine Chapter of the American College of Pediatrics, the Catholic Diocese of Portland and the Maine Organic Farmers and Growers Association.

Increased bacterial resistance to drugs used to treat animals can harm the effectiveness of these same drugs to treat people. For instance, if the antibiotic, virginiamycin, can be administered to animals for nontherapeutic uses, allowing bacteria to become more resistant to it and its human analog, synercid, which is used to treat patients with severe infections. Or if an animal has salmonella that is resistant to drugs commonly administered for nontherapeutic reasons, it might no longer be effectively treated with ampicillin, tetracycline, sulfa drugs or streptomycin, and would need more advanced drugs, further encouraging salmonella resistance to drugs people use for food poisoning.

It gets more complicated. Chickens are treated for E. coli in their lungs and guts with fluoroquinolones, but its widespread use increases the risk of humans getting fluoroquinolone-resistant campylobacter, which resides in the guts of chickens and in humans causes get diarrhea, cramping, abdominal pain, fever and, occasionally, life-threatening infections. Already, doctors have found an increase in the prevalence of drug-resistant staph and strep infections in recent years, as well as an unsettling rise in antibiotic-resistant tuberculosis.

These practices matter especially anytime patients risk infection, in cancer or AIDS treatment, among the elderly and very young. From a purely financial view, the congressional Office of Technology Assessment several years ago estimated that just six type of drug-resistant bacteria annually increase hospital treatment costs $1.3 billion.

The answer to this trend, advocates say reasonably, is to pass federal legislation that phases out the routine feeding of medically important antibiotics to healthy livestock and poultry. The bills, introduced by Sen. Edward M. Kennedy in the Senate and Rep. Sherrod Brown in the House, would slowly ban the use of nontherapeutic uses of specific drugs in the absence of disease. The Senate bill also authorizes funds to help farmers defray costs of the phase out.

The good news is that a more-considered use of antibiotics can dramatically slow the spread of resistant bacteria and save money. Informing people that their child’s or their own illness would be cured more quickly in the future if they insist on more careful use of antibiotics now is an effective message. Congress would set the right tone by passing this legislation.