Reducing Antibiotic Use Lowers Rates of Drug-Resistant Bacteria

Fewer antibiotic prescriptions lead to fewer superbugs. That's the take-home message behind a new study in the Oct. 15, 2005 issue of Clinical Infectious Diseases, now available online. The study found that reducing antibiotic use for pediatric respiratory tract infections resulted in lower rates of carriage of drug-resistant bacteria.

Drug-resistant bacteria, commonly called superbugs, are fast becoming a problem due to overuse and inappropriate prescribing of antibiotics. Streptococcus pneumoniae bacteria, also called pneumococci, are commonly found in children's noses and throats, and can result in ear infections, sinusitis, pneumonia and even meningitis. Many pneumococcal infections are treated with penicillin, but resistance to the drug is making the microbes more difficult to control.

Researchers in France tested two intervention methods intended to reduce the rate of carriage of penicillin-resistant pneumococci in kindergarteners. The prescription-reduction method involved not prescribing antibiotics for respiratory tract infections that were thought to be viral, since antibiotics work against bacteria, not viruses. The dose/duration method involved using only recommended doses of antibiotics for no longer than five days. The researchers also targeted physicians, pharmacists, parents, and children in the groups receiving both interventions with an information campaign about antibiotic resistance and appropriate antibiotic use. A control group of children and their doctors received no specific information about antibiotic use.

The study was conducted from January through May of 2000. By the end of the study, antibiotic use had declined by more than 15 percent in both intervention groups, compared to less than 4 percent in the control group. Although colonization by regular pneumococci was higher in the intervention groups than in the control group, colonization by penicillin-resistant pneumococci was lower in the intervention groups than in the control group. The prescription-reduction group saw the greatest decline in penicillin-resistant colonization (from 53 percent to 35 percent), and the dose/duration group dropped from 55 percent to 44 percent. The control group remained nearly unchanged. This suggests that reduced antibiotic pressure allows drug-susceptible bacteria to re-establish themselves as dominant colonizers of the respiratory tract.

Implementing intervention programs that are "focused on populations most exposed to antibiotics," that is, children, is the first step in reining in superbugs, said lead author Didier Guillemot, MD, PhD, of Institut Pasteur.

Intervention methods such as reducing the number of prescriptions and, when ordered, the dose and duration of antibiotics, "can induce significant and rapid reductions" of penicillin-resistant pneumococcal colonization in areas that have high rates of drug-resistant bacteria, according to the study. In essence, doctors can make their own jobs easier by prescribing antibiotics more judiciously, thus slowing the spread of superbugs.

Source: Infectious Diseases Society of America (IDSA