Daily bathing with chlorhexidine-based soap and the prevention of Staphylococcus aureus transmission and infection

Abstract

Objective: Determine whether daily bathing with chlorhexidine-based soap decreased methicillin-resistant Staphylococcus aureus (MRSA) transmission and intensive care unit (ICU)-acquired S. aureus infection among ICU patients.

Design: Prospective pre-post-intervention study with control unit.

Setting: A 1,250-bed tertiary care teaching hospital.

Patients: Medical and surgical ICU patients.

Methods: Active surveillance for MRSA colonization was performed in both ICUs. In June 2005, a chlorhexidine bathing protocol was implemented in the surgical ICU. Changes in S. aureus transmission and infection rate before and after implementation were analyzed using time-series methodology.

Results: The intervention unit had a 20.68% decrease in MRSA acquisition after institution of the bathing protocol (12.64 cases per 1,000 patient-days at risk before the intervention vs 10.03 cases per 1,000 patient-days at risk after the intervention; β, -2.62 [95% confidence interval (CI), -5.19 to -0.04]; P = .046). There was no significant change in MRSA acquisition in the control ICU during the study period (10.97 cases per 1,000 patient-days at risk before June 2005 vs 11.33 cases per 1,000 patient-days at risk after June 2005; β, -11.10 [95% CI, -37.40 to 15.19]; P = .40). There was a 20.77% decrease in all S. aureus (including MRSA) acquisition in the intervention ICU from 2002 through 2007 (19.73 cases per 1,000 patient-days at risk before the intervention to 15.63 cases per 1,000 patient-days at risk after the intervention [95% CI, -7.25 to -0.95]; P = .012)]. The incidence of ICU-acquired MRSA infections decreased by 41.37% in the intervention ICU (1.96 infections per 1,000 patient-days at risk before the intervention vs 1.15 infections per 1,000 patient-days at risk after the intervention; P = .001).

Conclusions: Institution of daily chlorhexidine bathing in an ICU resulted in a decrease in the transmission of S. aureus, including MRSA. These data support the use of routine daily chlorhexidine baths to decrease rates of S. aureus transmission and infection.

Figure 1. Unadjusted Rates of Methicillin-resistant Staphylococcus aureus (MRSA) Acquisition per 1000 Patient-Days at Risk for the Intervention Intensive Care Unit (ICU)