Someday, people may look back on the 20th and 21st centuries with nostalgia, as the time when it was possible to treat bacterial infections. With antibiotic resistance on the rise, many antibiotics could be nearly useless in a few generations. As part of a series of reports on antibiotic resistance, the American Academy of Pediatrics committee has published a report on the use of antibiotics in agriculture. In addition to the antibiotics that go to sick animals, healthy animals are given antibiotics to help them grow. Many of these are similar or identical to drugs used in humans, which has spurred fears that overuse of antibiotics on animals can encourage the development of resistant bacteria—making the antibiotics useless in humans, too.

What the researchers wanted to know: How does the use of antibiotics on healthy animals affect pediatric practice?

What they did: The authors reviewed studies on antibiotic use in agriculture and how it relates to people, including disease in infants and children.

What they concluded: Using antibiotics on animals is the perfect way to encourage resistant bacteria to evolve, and slaughtering the animals and bringing them to market is a fine way to get those resistant bacteria out into humans. Meat in grocery stores is often infected with antibiotic-resistant bacteria. The authors describe one experiment in which some chickens were given low-dose tetracycline in their feed and others were not. In two weeks, 90 percent of the chickens who got tetracycline were excreting tetracycline-resistant bacteria. In six months, about a third of the people who lived on farms were excreting resistant bacteria, too. Children, the authors say, are particularly susceptible to infections with some of the bacteria that are likely to develop resistance.

What the study means to you: Maybe giving low-dose antibiotics to animals isn't such a great idea, but giving the antibiotics helps animals grow faster and keeps meat cheap.

Caveats: Of course, agricultural use is only part of the problem—antibiotics are often prescribed for people who don't really need them—but the Institute of Medicine estimates that 40 percent of antibiotics in the United States go to animals every year.

Find out more: Information on antibiotic resistance from the Centers for Disease Control and Prevention

Read the article: Shea, K.M., and the Committee on Environmental Health and Committee on Infectious Diseases. "Nontherapeutic Use of Antimicrobial Agents in Animal Agriculture: Implications for Pediatrics." Pediatrics. September 2004, Vol. 114, No. 3, pp. 862–868.

Abstract online: http://pediatrics.aappublications.org