Comprehensive strategy including prophylactic mupirocin to reduce Staphylococcus aureus colonization and infection in high-risk neonates.

OBJECTIVE: To examine the use of long-term prophylactic mupirocin as part of a comprehensive strategy in reducing Staphylococcus aureus colonization and infection in a neonatal intensive care unit (NICU). STUDY
DESIGN: Twice daily mupirocin was applied to all infants admitted to the NICU throughout hospitalization starting in 2004. S. aureus surveillance was implemented in 2008. The efficacy of these practices was evaluated with a retrospective review of infants admitted from 2004 to 2010 found to be colonized or infected with S. aureus. RESULT: During the study period, 66 of 6283 NICU infants had a S. aureus infection with 67% methicillin resistance. There were three distinctive S. aureus outbreaks, the first being a methicillin-resistant strain July 2004. After implementation of daily mupirocin, the outbreak was eradicated and the rate of S. aureus infection significantly decreased (1.82 to 0.40/1000 patient-days-at-risk, P=0.0049). Mupirocin was discontinued March 2005 followed by a methicillin-sensitive S. aureus outbreak November 2005. In December 2005, mupirocin was reinstituted and has continued to present day, again significantly reducing S. aureus infections (1.42 to 0.33/1000 patient-days-at-risk, P<0.0001) with zero isolates resistant to mupirocin. In the pre-mupirocin period, S. aureus colonization was upwards of 60% now with rates typically <5%. S. aureus colonization strongly predicted later invasive infection (P<0.0001).
CONCLUSION: Although controversial, prophylactic mupirocin in all NICU infants has acted as a barrier to colonization and markedly decreased S. aureus infection rates over a 5-year period.