Erythromycin prophylaxis for pertussis.

A neonate admitted to the newborn nursery was found to have bacteriologically proven Bordetella pertussis whooping cough, and two of seven infants exposed to this child became infected. Erythromycin administration to the seven infants apparently prevented further infection as well as the appearance of clinical disease in the two infected infants. This limited experience supports previous reports of the efficacy of erythromycin in preventing B. pertussis infection and disease in susceptible children.