Farm antibiotics trigger health risks

To improve meat safety, the federal government for years has allowed ranchers and farmers to feed antibiotics to beef cattle and poultry to control bacteria deemed harmful.

That practice, however, is coming under increasing criticism from some consumer groups and public-health organizations. Overreliance on antibiotics on the farm, they say, may be contributing to a larger public-health problem: the excessive use of antibiotics in medicine and consumer products in general.The trend, they say, is giving rise to bacteria that resist the antibiotics used to treat humans for the diseases associated with the microscopic organisms. Some of these antibiotics also are used as food and water additives to ward off illness and boost the meat yield in livestock.

"In certain cases, there are fewer and fewer antimicrobials available to treat serious diseases in humans," says Sharon Thompson, an associate director in the U.S. Food and Drug Administration's Center for Veterinary Medicine in Rockville, Md.

At issue, researchers say, is not the use of antibiotics to combat specific disease outbreaks among livestock. Instead, the concern centers around farmers' routine use of antibiotics. Livestock use accounts for roughly half of the 25,000 tons of antibiotics produced in the United States each year, according to a report last month from the Institute of Medicine. It adds that 40 percent to 80 percent of the antibiotics applied on the farm are unnecessary.

So far, evidence that the use of antibiotics in agriculture is having significant adverse off-farm effects is inconclusive, according to the Animal Health Institute, a pharmaceutical-industry organization based in Washington D.C.

Speaking at a veterinary meeting in College Park, Md., earlier this year, Richard Carnevale AIH vice president noted that while antibiotic resistance in general is a problem, "how much of it is really due to animal drugs and what is the medical impact? . . . The problem is complex," and "the risks of using animal drugs must be put in context with the real risk factors associated with food-borne illness."

Still, the AIH acknowledges that available studies "are suggestive" that "injudicious use" of antibiotics on the farm can lead to the development of treatment-resistant strains of unwanted bacteria.