Unrelated strain methicillin-resistant Staphylococcus aureus colonization of health care workers in a neonatal intensive care unit: findings of an outbreak investigation.

Three neonates and 5 health care workers were identified as colonized with methicillin-resistant Staphylococcus aureus (MRSA) out of 222 individuals screened during an outbreak investigation in an 18-bed neonatal intensive care unit. Two of 3 MRSA neonatal isolates demonstrated identical pulsed-field gel electrophoresis clonal patterns but no clonal association was found among isolates from the 5 employees or between employees and neonates. Increased MRSA-unrelated strain colonization among health care workers supports increased MRSA community prevalence and probable decreased utility of mass screening.