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

ABSTRACT Background : Medical procedures and patient care activities may facilitate environmental shedding of healthcare-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 versus 2.2 log10 colony-forming units per swab; P 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.