In a recent issue of Pediatrics, researchers from the Boston University School of Medicine reported that almost half of 610 pediatricians who responded to a survey indicated that parents pressure them to prescribe antibiotics for children in whom the drugs may not be effective. Forty percent of physicians responded that 10 or more times during one month a parent had requested an antibiotic when the physician did not think it was indicated. And about one-third of these physicians said they at times comply with these demands. (4)

In the March 18, 1998, issue of the Journal of the American Medical Association, researchers from the University of Colorado Health Sciences Center in Denver evaluated antibiotic prescribing practices for children under 18 who had been diagnosed with common colds, upper respiratory infections (URI's), or bronchitis. They found that in a sample made up of 531 pediatric office visits, antibiotics were prescribed to a significant number of children who present with common colds (44 percent), URI's (46 percent), and bronchitis (75 percent). Extrapolating their data to the United States, the authors said this translated to 6.5 million antibiotics prescriptions written for children with common colds or URI's, and 4.7 million antibiotics prescriptions for children with bronchitis. (5)

Results of an earlier study by University of Colorado Health Sciences Center researchers reported in the Sept. 17, 1997, issue of JAMA showed that adults too, often are prescribed antibiotics for colds, URI's, and bronchitis. Data from the 1992 National Ambulatory Medical Care Survey showed that office visits for colds, URI's, and bronchitis resulted in 12 million antibiotics prescriptions for adult men and women in 1992. A total of 51 percent of patients with colds, 52 percent of patients with URI's, and 66 percent of patients with bronchitis received antibiotics. (6)

The question here, basically, is how does the environment - in this case, one in which antibiotics are present - affect the evolution of bacteria and the possible proliferation of resistant pathogens. In Darwinian terms, bacteria that are most fit to survive in a particular environment are the ones that will survive and reproduce. Thus, the selective environmental pressure brought on by the inappropriate use of antibiotics can provide a breeding ground for the emergence of resistant strains.

Another practice that may encourage the growth of resistant bacterial strains occurs when patients decide on their own to stop taking the prescription medicine early because they feel better. Later on, they may use the antibiotics that they have saved - in a less-than-therapeutic amount - to "treat" another infection. (3)

This practice, too, may result in environmental conditions within the body that favor the growth of resistant bacteria. With millions of bacteria competing with one another within this human ecosystem, the use of subtherapeutic amounts of antibiotics could kill off some of the bacteria that are susceptible, leaving a clear field for the explosive growth of strains that "thumb their noses" at these medications.

Thus, educating the public and health-care practitioners about the responsible use of antibiotics could have an impact on the spread of antibiotic resistance.

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