Clostridium difficile: epidemiology and clinical features.

To determine the epidemiologic features of Clostridium difficile in Halifax, Nova Scotia, the authors studied two groups of hospitalized patients, one group of outpatients and a fourth group of 54 healthy subjects. The first group consisted of 29 patients with diarrhea, whose stool was found to contain C. difficile or its cytotoxin, or both. Twenty-two underwent sigmoidoscopic examinations; of these, 18 had abnormal colonic mucosa and 6 of the 18 had pseudomembranous colitis. In the second group of 127 patients on general medical wards, 22 (17%) carried C. difficile. Thirteen of the 22 had diarrhea, and 3 had pseudomembranous colitis. Clustering of patients with C. difficile was evident. In vitro production of toxin by isolates of C. difficile from these patients was more likely if antibiotics had been given. Only 1 (4.5%) of the 22 outpatients with various gastrointestinal disorders (group 3) and none of the 54 healthy subjects (group 4) carried C. difficile. The clinical spectrum of infection with C. difficile extended from asymptomatic patients to those with nonspecific colitis and pseudomembranous colitis.