Despite pleas from health officials, pediatricians are prescribing antibiotics unnecessarily, according to a new study by Boston's Brigham and Women's Hospital and Harvard Medical School.

The study analyzed nearly 4,000 records of children who visited medical offices with sore throats. Most of the time, a sore throat is caused by a viral infection, which has no treatment. But in about 15 percent to 30 percent of cases, the sore throat is caused by a streptococci bacterial infection, which can be detected with a throat culture and treated with antibiotics.

The researchers found that doctors prescribed antibiotics 53 percent of the time --- far exceeding the expected 15 percent to 30 percent prevalence of strep throat, according to a study in the Nov. 9 issue of the Journal of the American Medical Association.