Control of a methicillin-resistant Staphylococcus aureus outbreak in a neonatal intensive care unit by unselective use of nasal mupirocin ointment

In September 1996, an outbreak of methicillin-resistant Staphylococcus aure us (MRSA) colonization occurred in the neonatal intensive care unit (NICU) of our hospital. After failing to control the outbreak by conventional meth ods we implemented an intranasal blanket use programme of mupirocin ointmen t from the beginning of November 1997. In the programme, patients who had b een carrying MRSA received intranasal administration of the ointment three times daily for the first three days and consecutively three times weekly, while newly admitted patients and those who had not been colonized were pro phylactically medicated three times weekly. This blanket administration was executed for one month. Methicillin-resistant Staphylococcus aureus coloni zation became undetectable in all but one intubated inpatient who had alrea dy been colonized before the start of the programme, and no new acquisition s occurred until the middle of January 1998, seven weeks after the terminat ion of the blanket use programme. The rate of colonized patients in the uni t also decreased. During and after the programme, neither an increase in mi nimum inhibitory concentration for the antibiotic nor apparent adverse reac tions in any of the treated patients were observed. We concluded that this procedure is an effective method of controlling an MRSA outbreak in an NICU when the outbreak cannot be managed with conventional measures. (C) 2000 T he Hospital Infection Society.