Outbreak of staphylococcal infection in two hospital nurseries traced to a single nasal carrier.

In late January and early February 1983, an outbreak of skin infections (7 of 145 infants) caused by a penicillin/erythromycin resistant strain of Staphylococcus aureus (SA), phage type 3A/3C, occurred in our newborn nursery. A week following the first cluster of infections, another nursery outbreak due to SA with the same antibiogram occurred in a nearby community hospital (11 of 114 infants). Subsequently, a second cluster of infections with the same SA was identified at our nursery. The epidemic strain was carried in the anterior nares of a single nurse who worked at both hospital nurseries on alternate weeks. Investigation revealed that the nurse had an upper respiratory tract infection during each of these outbreaks--simulating "a cloud baby." No further infections have occurred since this nurse was treated and her SA nasal carrier state eliminated.