Clostridium difficile: history of its role as an enteric pathogen and the current state of knowledge about the organism.

Clostridium difficile is the most frequently identified enteric pathogen in patients with antibiotic-associated diarrhea and colitis. It accounts for 10%-25% of all cases of antibiotic-associated diarrhea and virtually all cases of antibiotic-associated pseudomembranous colitis. Clinical features that distinguish infection with C. difficile from that due to many other enteric pathogens are hyperpyrexia, leukemoid reactions, toxic megacolon, pseudomembranous colitis, hypoalbuminemia, and chronic diarrhea. Factors important in the pathogenesis of disease are exposure to antibiotics, the presence of C. difficile in the patient's indigenous flora or acquisition of the organism from an environmental source, production of toxin A, and age-related susceptibility. The criterion standard for testing is the tissue culture assay; alternatives are culture and other methods of antigen detection including EIA, dot blot hybridization assay, and latex agglutination. The optimal drug for treatment is vancomycin; however, metronidazole is often used because it is less expensive. At present the main problems associated with C. difficile infection are treatment of patients with ileus, the management and prevention of nosocomial epidemics, and the management of repeated relapses.