Mupirocin prophylaxis for the prevention of nosocomial infections due to nasal carriers of Staphylococcus aureus is of no use in nonsurgical patients as yet

Objective. To assess the efficacy of mupirocin prophylaxis in preventing nosocomial Staphylococcus aureus infections in nonsurgical patients. Design. Randomised, double-blind, placebo-controlled multicentre trial. Method. In three tertiary-care university hospitals and one peripheral teaching hospital, 1602 culture-proven nasal S. aureus carriers hospitalized on nonsurgical wards were treated with mupirocin 2% nasal ointment (n = 793) or placebo ointment (n = 809), twice daily for 5 days, starting 1 to 3 days after admission. Data collected included nosocomial S. aureus infections according to defined criteria, in-hospital mortality, duration of hospitalisation, and time to nosocomial S. aureus infection. S. aureus isolates were genotyped to assess whether infection was caused by endogenous strains. Results. The mupirocin and placebo groups did not differ statistically significantly in the rates of nosocomial S. aureus infections (mupirocin group: 2.6%; placebo group: 2.8%; risk difference: 0.2% (95% CI: -1.5%-1.9%)), mortality (mupirocin: 3.0%; placebo: 2.8%; risk difference: -0.2% (95% CI: -1.9%-1.5%)), or duration of hospitalisation (median for both groups: 8 days). However, the time to nosocomial S. aureus infection was increased in the mupirocin group from 12 to 25 days (p = 0.28). A total of 77% of S. aureus nosocomial infections were endogenous. Conclusion. Routine culture for nasal carriage of S. aureus at admission and subsequent mupirocin prophylaxis in the carriers did not prevent nosocomial S. aureus infections in nonsurgical patients