An outbreak of Serratia marcescens transmitted by contaminated breast pumps in a special care baby unit.

Laboratory surveillance of clinical isolates for Serratia spp. revealed a sudden increase from babies in the Special Care Baby Unit (SCBU). It was established that breast-milk pumps on the post-natal wards were being disinfected inadequately, resulting in contamination of milk and cross-infection within the SCBU. Thirty babies were colonized and no deaths were attributable to the organism. Rectal carriage by the babies was common and often prolonged. The outbreak was brought under control when the method of disinfection of the pumps was changed from soaking in hypochlorite solution to washing at 80 degrees C.