MOLECULAR EPIDEMIOLOGY OF STAPHYLOCOCCAL SCALDED SKIN SYNDROME IN PREMATURE-INFANTS

Background. Outbreaks of nosocomial staphylococcal scalded skin syndro me (SSSS) in infants have been well-described associated with the well baby nursery or delivery room. We describe two cases of SSSS in very low birth weight infants in a neonatal intensive care unit (NICU) and the success of infection control strategies used to prevent an outbrea k. Methods. Staphylococcal scalded skin syndrome was diagnosed in two infants in the NICU: Case I (a 47-day-old, formerly 530-g female); and Case II diagnosed 48 h later (a 41-day old, formerly 706-g female). M ultiple infection control measures were implemented: (1) isolation and intravenous antibiotic treatment of cases; (2) placement of exposed i nfants into a cohort; (3) prophylactic mupirocin treatment of the ante rior nares of all infants in the NICU and staff colonized with Staphyl ococcus aureus; and (4) personnel hand washing with hexachlorophene. D etection of exfoliative toxin A and studies to determine the genetic r elatedness of S. aureus strains isolated from patients and staff were performed. Results. In addition to the two SSSS cases, S. aureus was i solated from 2 of 12 (17%) exposed asymptomatic infants, 2 of 20 (10%) ancillary staff, 8 of 30 (27%) nurses and 6 of 24 (25%) physicians. E xfoliative toxin A-producing strains were isolated from both cases and one asymptomatic infant. No toxin was expressed by strains isolated f rom staff. Pulse field gel electrophoresis demonstrated genetically id entical strains of S. aureus from the two SSSS cases and the asymptoma tic infant, whereas three staff members harbored strains genetically r elated to the case strain. Unexpectedly two additional unique clusters of genetically related S. aureus strains were identified from the sur veillance cultures. Conclusions. This report documents the rare occurr ence of nosocomial SSSS attributed to transmission in the NICU among e xtremely low birth weight infants. Multiple infection control strategi es were effective in limiting the outbreak. Molecular epidemiology inv estigation supported a unique S. aureus strain responsible for this ev ent and the presence of bidirectional spread between staff and patient s of non-toxin-producing strains.