Antibiotic-associated pseudomembranous colitis: an epidemiologic investigation of a cluster of cases.

Ten cases of antibiotic-associated colitis (AAC) were identified at a hospital in Washington, D.C., from March 17 to May 9, 1979. No geographic clustering of cases was found, nor was an association with increased use of antibiotics demonstrated. Exposure to aminoglycosides, cephalosporins, and clindamycin was associated with AAC, as was a history of enemas in the seven days before the onset of illness (P=0.045). This association was strengthened when gastrointestinal procedures-defined as (1) three or more enemas per week, (2) the insertion of a nasogastric tube for two or more days, or (3) gastrointestinal surgery-were performed within seven days of the onset of illness (P=0.007). Clostridium difficile was not isolated from the hospital environments, nursing personnel, or family members of the patients. C. difficile was isolated from stool specimens of five (36%) of 14 patients who served as controls.