Epidemiology of Antibiotic-Associated Colitis: Isolation of Toxigenic Clostridium Difficile from the Environment and Contacts of Patients with Antibiotic-Associated Colitis.

C. difficile is the most important cause of antibiotic-associated colitis, but little is known of its sources and epidemiology. Three clusters of C. difficile diarrhea were studied at the University of Michigan Hospital. Using selective media for C. difficile containing cycloserine and cefoxitin (CCFA), cultures were obtained from the environment of patients with the organism in their stools. When stool carriers had diarrhea, 9.3 percent of 910 cultures of floors and surfaces subject to fecal contamination were positive. In control areas where there were no carriers, only 2.6 percent of 497 cultures were positive (p < 0.005). Contamination was also greater in the room environment of a patient with colitis (19.6 percent of samples positive) than in the room of an asymtomatic carrier (6.8 percent positive). C. difficile was also isolated from h and s or stools of hospital personnel. The organism was isolated from surfaces in the hospital laundry, from sewage and soil, and from the home of a patient. Twenty-three air and 25 food cultures were negative. Twenty environmental isolates tested for their cytotoxigenicity were positive. When the organism was inoculated onto an unused hospital floor, it persisted there for five months. The persistence of C. difficile in the environment could be attributable to the residual nature of its spores. The recommended 1:127 dilution of quaternary ammonium chloride compounds commonly used as a hospital disinfectant was not sporicidal, and therefore its efficiency as a germicidal agent was limited. A two percent alkaline glutaraldehyde solution was demonstrated to be sporicidal. This investigation provides evidence that environmentally derived organisms may be important in the spread of antibiotic-associated colitis. The h and s of hospital personnel may be a most important vehicle of transmission. Enteric isolation precautions should be instituted for patients with antibiotic-associated or C. difficile positive stools and diarrhea.PhDEnvironmental scienceUniversity of Michiganhttp://deepblue.lib.umich.edu/bitstream/2027.42/157939/1/8025707.pd