Shedding of multidrug-resistant gram-negative bacilli by colonized patients during procedures and patient care activities

Background: Medical procedures and patient care activities may facilitate environmental shedding of health care-associated pathogens. Methods: We conducted a cohort study of hospitalized patients in contact precautions for carriage of extended-spectrum beta-lactamase (ESBL)-producing gram-negative bacilli (N = 38) or carbapenem-resistant gram-negative bacilli (CR-GNB) (N = 22) to determine the frequency of environmental shedding during procedures and care activities. Perirectal, wound, and skin were cultured for ESBL-producing and CR-GNB. High-touch surfaces and portable equipment were disinfected before and cultured after procedures; control cultures were collected in the absence of procedures. Results: Of 60 patients enrolled, 34 (57%) had positive perirectal and/or skin or wound cultures. For these 34 patients, 15 (44%) shed their colonizing organism to surfaces during 1 or more procedures. Patients with shedding had significantly higher concentrations of the pathogens recovered from perirectal swabs than those with no shedding (mean, 3.5 vs 2.2 log io colony-forming units per swab; P < .01). Environmental shedding occurred more frequently during procedures and care activities than in the absence of a procedure (21 of 117, 18% vs 1 of 61, 2%; P < .01), and 6 of 56 (10%) portable devices used for procedures became contaminated. Conclusions: Environmental shedding of antibiotic-resistant gram-negative bacilli occurs frequently during medical procedures and patient care activities. Decontamination of surfaces and equipment and approaches that reduce the burden of carriage could reduce the risk for dissemination. Published by Elsevier Inc. on behalf of Association for Professionals in Infection Control and Epidemiology, Inc.