Epidemiology, risk factors and prevention of nosocomial Clostridium difficile infections.

Clostridium difficile is responsible for 10-25% of cases of antibiotic-asso ciated diarrhea (AAD) and for virtually all cases of antibiotic-associated pseudo-membranous colitis (PMC). This anaerobic spore-forming bacterium has been identified as the leading cause of nosocomial infectious diarrhea in adults. Pathogenesis relies on a disruption of the normal bacterial flora o f the colon, a colonization by C. difficile and the release of toxins A and B that cause mucosal damage and inflammation. Incidence of C. difficile in testinal disorders usually varies from one to 40 per thousand patient admis sions. Risk factors for C. difficile-associated diarrhea include antimicrob ial therapy, older age (> 65 years), antineoplastic chemotherapy, and lengt h of hospital stay. Nosocomial transmission of C. difficile via ore-fecal r oute occurs in 3-30% of total patient admissions but it remains asymptomati c in more than 66% of cases. Persistant environmental contamination and car rying of the organism on the hands of hospital staff are common. Measures t hat are effective in reducing cross-infection consist of an accurate and ra pid diagnosis, an appropriate treatment, an implementation of enteric preca utions for symptomatic patients, a reinforcement of hand-washing and a dail y environmental disinfection. C. difficile is a common cause of infectious diarrhea and should be therefore systematically investigated in patients wi th nosocomial diarrhea. (C) 2000 Editions scientifiques et medicales Elsevi er SAS.