Nursing homes residents have a high prevalence of multidrug-resistant organism (MDRO) colonization. Recent trials demonstrated that decolonizing residents reduces infection. However, decolonization’s impact on environmental MDRO contamination is not well understood.

We performed a 9-month pilot (3-month baseline, 3-month phase-in and 3-month intervention) in 3 nursing homes implementing routine chlorhexidine bathing/showering and nasal iodophor. We repeatedly tested for colonization via skin and nasal swabs for methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Enterococcus (VRE), extended-spectrum beta-lactamase producers (ESBLs), and carbapenem-resistant Enterobacterales (CRE). We also swabbed high-touch surfaces in rooms of MDRO carriers for MDRO fomite contamination.

Decolonization decreased the odds of MDRO colonization in nursing home residents by 55% (OR 0.45, P < 0.001, raw reduction from 46% (411/900) to intervention: 29% (262/900); colonization with MRSA, VRE, and ESBL all significantly decreased (P < 0.001). Among residents who remained colonized with any MDRO, 288/330 (87%) of high-touch bedroom objects were colonized with ≥1 MDRO. In a multivariable analysis, MDRO fomite contamination in rooms of MDRO carriers was associated with antibiotic use (OR = 1.54 [95% CI: 1.19–1.98], wound presence (OR = 1.34 (95% CI: 1.02–1.77), and specific fomites such as bedside table/bedrails (OR = 12.7 (95% CI: 9.37–17.25), but not the intervention period (OR = 1.02 [0.81–1.27]).

Routine chlorhexidine bathing and nasal iodophor significantly reduced MDRO body colonization among nursing home residents. However, in rooms of residents who remained MDRO carriers, environmental contamination was unchanged during the decolonization intervention. Efforts to ensure fomite surface clearance in rooms of MDRO carriers may be key to reducing environmental MDRO spread.