Antibiotics are not effective in acute viral bronchiolitis. Nevertheless, they are used in 34-99% of bronchiolitis cases. Bronchiolitis is a viral respiratory tract infection, often caused by RSV. Farley and colleagues reviewed 7 trials with a total of 824 patients evaluating the effectiveness of antibiotics in bronchiolitis. Except for one large trial, these studies were placebo-controlled.
This systematic review did not find evidence for a beneficial effect of antibiotics. Length of stay was similar in 350 infants treated with azithromycin versus placebo (5.2 vs 5.8 days). The authors conclude that antibiotics should not be used in bronchiolitis, although they keep the possibility open that antibiotics are needed for a subgroup of mechanically ventilated infants. This publication shows that withholding antibiotics to infants with bronchiolitis may have an important beneficial effect on the global rise of antibiotic resistance without affecting disease outcome.