Objective: To assess the role of environmental contamination in the transmission of multidrug-resistant bacteria to healthcare workers' clothing.
Design: Prospective cohort.
Setting: Six intensive care units at a tertiary care hospital.
Subjects: Healthcare workers including registered nurses, patient care technicians, respiratory therapists, occupational/physical therapists, and physicians.
Interventions: None.
Measurements and main results: One hundred twenty of 585 (20.5%) healthcare worker/patient interactions resulted in contamination of healthcare workers' gloves or gowns. Multidrug-resistant Acinetobacter baumannii contamination occurred most frequently, 55 of 167 observations (32.9%; 95% confidence interval [CI] 25.8% to 40.0%), followed by multidrug-resistant Pseudomonas aeruginosa, 15 of 86 (17.4%; 95% CI 9.4% to 25.4%), vancomycin-resistant Enterococcus, 25 of 180 (13.9%, 95% CI 8.9, 18.9%) and methicillin-resistant Staphylococcus aureus, 21 of 152 (13.8%; 95% CI 8.3% to 19.2%). Independent risk factors associated with healthcare worker contamination with multidrug-resistant bacteria were positive environmental cultures (odds ratio [OR] 4.2; 95% CI 2.7-6.5), duration in room for >5 mins (OR 2.0; 95% CI 1.2-3.4), performing physical examinations (OR 1.7; 95% CI 1.1-2.8), and contact with the ventilator (OR 1.8; 95% CI, 1.1-2.8). Pulsed field gel electrophoresis determined that 91% of healthcare worker isolates were related to an environmental or patient isolate.
Conclusions: The contamination of healthcare workers' protective clothing during routine care of patients with multidrug-resistant organisms is most frequent with A. baumannii. Environmental contamination was the major determinant of transmission to healthcare workers' gloves or gowns. Compliance with contact precautions and more aggressive environmental cleaning may decrease transmission.