Effect of mupirocin decolonization on subsequent methicillin-resistant Staphylococcus aureus infection in infants in neonatal intensive care units

Objective: To evaluate whether topical mupirocin treatment can effectively decolonize methicillin-resistant Staphylococcus aureus (MRSA) carriage and reduce subsequent MRSA infection in neonates. Methods: During a 1-year period, the infants admitted to our neonatal intensive care units (NICUs)-1 and NICU-2 were included, and specimens from the nares and umbilicus were obtained within 24 hours, and specimen collection was repeated weekly for 2 weeks. Mupirocin was administered for 5 days to the infants with MRSA colonization in NICU-1 during the first half of the year and then switched to those in NICU-2 during the second half of the year. Results: A total of 525 infants were recruited: 257 infants in the treatment group and 268 in the control group. MRSA colonization was detected in 130 infants (25%) during NICU stay, which is a similar rate in both groups. Twenty-two (4.2%) episodes of MRSA infection were identified. The rate of MRSA infection was significantly higher in infants with prior colonization than in those without (10.2% vs. 2.3%, P < 0.001). Among the infants with prior colonization, the rate of MRSA infection in the treatment group was significantly lower than that in the control group (3.2% vs. 16%, P = 0.014), and the rate in the treatment group was comparable to that in those without colonization (P = 0.7804). Of the 15 infants with both clinical and colonizing isolates, indistinguishable strains between the paired isolates from the same infant by molecular methods were identified in 14 infants (93%). Conclusion: Administering mupirocin topical therapy to MRSA-colonized infants in NICUs might reduce subsequent MRSA infections during hospitalization in these infants. A large-scale study should be conducted.