Research in context
Evidence before this study
Several cluster-randomised trials in intensive care units (ICUs) have led to the widespread adoption of universal ICU decolonisation involving daily chlorhexidine bathing with or without nasal ointments to prevent bloodstream infections and methicillin-resistant Staphylococcus aureus (MRSA).These trials have also led to national guidance in the USA for the use of daily chlorhexidine bathing in ICUs to reduce device-associated infections, specifically central line-associated bloodstream infections. Only modest experimental evidence has been gathered about the effect of universal decolonisation in non-ICU settings. We searched PubMed for “chlorhexidine bathing” (MeSH Terms) and “hospital,” excluding “intensive care unit”, or “ICU” and found four quasi-experimental studies. One study found a 64% reduction in hospital-associated MRSA and vancomycin-resistant enterococcus (VRE) infections compared with historical controls after 14 months of daily bathing with chlorhexidine in four general medical units at an academic centre. Another study found a 55% reduction in hospital-associated MRSA and a 36% reduction in hospital-associated VRE after chlorhexidine bathing for 7 months in a crossover study of four general medical units at an academic centre. A third study with a non-randomised, stepped-wedge design involving 19 months of hospital-wide chlorhexidine bathing reported a 29% reduction in Clostridium difficile infection with thrice weekly chlorhexidine bathing, and a 59% reduction in C difficile infection with daily chlorhexidine bathing. In the last study, one chronic care hospital unit was randomly assigned to bathe patients daily with chlorhexidine for 12 months resulting in a 71% reduction in MRSA incidence among 122 patients, although the reported benefit was not significant. All but one study used 2% no-rinse chlorhexidine cloths. Reported adherence with chlorhexidine bathing in these studies was approximately 60%.
Added value of this study
The ABATE Infection (active bathing to eliminate infection) trial is the first large-scale cluster-randomised trial to evaluate whether universal chlorhexidine bathing for all patients plus mupirocin for MRSA carriers in non-critical-care units reduces multidrug-resistant organisms and all-cause bloodstream infection. Chlorhexidine compliance was higher than in the four quasi-experimental studies reported above. We found that universal decolonisation did not reduce infection in the overall population, but in post-hoc analyses of patients with medical devices the regimen was associated with significant reductions in all-cause bloodstream infections and MRSA or VRE clinical cultures.
Implications of all the available evidence
Although previous single-centre, quasi-experimental studies in non-ICU settings found broad infection reduction benefits with daily chlorhexidine use in patients in academic hospitals, the ABATE Infection trial did not find significant benefits in non-critical-care patients. Our results contrast with those showing benefits of universal decolonisation over routine care in several trials of ICUs. Current US ICU guidance to use daily chlorhexidine bathing for prevention of central line-associated infections has led many hospitals to adopt daily chlorhexidine bathing for all patients with central lines and other devices, although evidence in non-ICU patients has been lacking. The post-hoc analysis in the ABATE Infection trial found that non-ICU patients with medical devices had a significant 37% reduction in MRSA and VRE and a significant 32% reduction in all-cause bloodstream infections. Patients with medical devices constituted only 10% of the inpatient population, but were responsible for 37% of MRSA and VRE cultures and 56% of all-cause bloodstream infections. Despite these findings, further research is needed to confirm these effects if the decolonisation strategy is applied only to patients with medical devices, since the ABATE Infection trial involved universal decolonisation in all patients.