Impact of Post-Discharge Chlorhexidine (CHG) and Mupirocin on MRSA Carriage in a Randomized Trial

Background: MRSA carriers experience a high risk of MRSA infection in the 6 months after hospital discharge. Reducing carriage during this critical period through decolonization may prevent a meaningful amount of infections and morbidity in MRSA carriers.

Methods: MRSA carriage was assessed in an ongoing randomized clinical trial of recently hospitalized MRSA carriers comparing post-discharge education (EDU) to education plus decolonization (DCL). DCL was comprised of serial 5-day courses of twice daily mupirocin, once daily 4% CHG skin cleansing of the body with rinsing, and twice daily 0.12% CHG oral rinse. These 5-day courses were repeated twice monthly for 6 months. Enrollment cultures were taken of the bilateral nares, throat, axilla/groin (as a single swab), and wound (if present), at baseline and months 1, 3, and 6 following enrollment. Carriage proportions were compared between arms by visit and site using chi-square tests.

Results: Among the 1,669 randomized patients included in this analysis (n=835 in EDU arm and n=834 in DCL arm), visit completion was 72% at 1 month (M1), 62% at 3 months (M3), and 50% at 6 months (M6) (trial ongoing).  At enrollment, there were no differences in MRSA carriage between the arms for each site and any site. Significantly greater reductions were seen in the DCL arm for all sites and all intervention visits (P<0.05) with the exception of wounds at M1 and M6 visits, which were affected by small sample size.  At M6, the DCL arm had a 48% (95% CI: 36, 57) greater reduction in MRSA carriage at any body site. For specific body sites at M6, the following percent reductions were seen: nares 56% (CI: 43, 65), throat 34% (CI: 6, 54), axilla/groin 54% (CI: 34, 68), and wound 41% (-15, 70).

Conclusion: Post-discharge decolonization plus MRSA education of recently hospitalized MRSA carriers is more effective than MRSA education alone in reducing colonization at multiple body sites. The impact of this intervention on MRSA infections in the high risk post-discharge period remains to be seen. Despite the reduction, carriers persist in both arms. It is not yet known if those who do not adhere to or fail decolonization have higher risks of disease.