Results of nasal screening for methicillin-resistant Staphylococcus aureus during a neonatal intensive care unit outbreak.

Recent reports have implicated community-associated methicillin-resistant Staphylococcus aureus (MRSA) as a cause of outbreaks in the neonatal intensive care unit (NICU). This study was conducted to determine whether community-associated MRSA caused such an outbreak in our NICU and the extent of nasal colonization with MRSA among exposed babies and health care workers. MRSA recovered from infected and colonized babies were genotyped by pulse-field gel electrophoresis (PFGE). Infection control measures were intensified and included nasal screening for MRSA colonization of exposed babies and all new admissions to the NICU within 24 hours of delivery. PFGE type A was recovered from five infected infants and colonized 81% of the exposed infants. The colonization rate during the outbreak was 9.3% and was 1.9% during admission screening. No MRSA infection occurred during 12 months while admission screening was implemented. Hospital-associated MRSA was the dominant strain in this outbreak. Higher colonization rates occurred during the outbreak period.