Nosocomial transmission of methicillin-resistant Staphylococcus aureus from a mother to her preterm quadruplet infants

Background: Patient-to-patient transmission of methicillin-resistant Staphylococcus aureus (MRSA) in neonatal intensive care units (NICUs) has been well described. We report the first documented outbreak of probable transmission of MRSA from a mother to 3 of her preterm quadruplet infants postnatally. Methods: Routine surveillance of clinical microbiologic laboratory reports revealed an increased incidence of MRSA infections in our NICU, including 3 of 4 preterm quadruplets. Surveillance cultures of the anterior nares of all patients and the quadrupletsʹ parents were performed to detect MRSA carriage. The isolates were typed by pulsed-field gel electrophoresis with the restriction endonuclease SmaI. Infection control strategies included mupirocin treatment and contact isolation precautions for infected/colonized infants. Results: Clinical cultures from infants A, C, and D and surveillance cultures of the quadrupletsʹ mother and 2 additional unrelated infants grew the same clone of MRSA. The motherʹs only identified risk factors for MRSA acquisition were 2 prepartum hospitalizations related to the multiple gestation and previous treatment with antibiotics. All anterior nares cultures were negative for MRSA after mupirocin treatment. Conclusions: Use of gowns and gloves by the family members of women with multiple gestations should be recommended to prevent transmission of potential pathogens in the NICU. (Am J Infect Control 2002;30:170-3.)