Outbreak of methicillin-resistant Staphylococcus aureus infection in a New Zealand hospital.

During a 17 month period from March 1985 to July 1986, 30 patients and four members of staff became infected or colonised with a single strain of methicillin-resistant Staphylococcus aureus (MRSA) during an outbreak which originated at Wellington Hospital. Initially, crossinfection occurred within the intensive care unit but infected or colonised patients became distributed to 14 hospital wards and to five other hospitals within New Zealand. MRSA septicaemia contributed to the death of two patients. The source of the epidemic strain of MRSA has not been established with certainty, but may have been introduced by a staff nurse known to be a carrier when employed at an Australian hospital. The investigation, management and eventual control of this first outbreak in New Zealand are described.