Almost a third of the prescriptions written for antibiotics in the U.S. are not necessary. A new report from the Centers for Disease Control and Prevention finds that doctors are writing prescriptions for things like colds, ear infections and bronchitis even though they won’t help. The unnecessary antibiotics are pushing the strength of drug-resistant superbugs. Researchers say about 13 percent of outpatient doctor visits result in an antibiotic prescription and 30 percent of them are unnecessary. That equals about 47-million unneeded prescriptions each year.