PREVALENCE AND PATHOGENICITY OF CLOSTRIDIUM-DIFFICILE IN HOSPITALIZED-PATIENTS - A FRENCH MULTICENTER STUDY

Background: Although Clostridium difficile is the main agent responsib le for nosocomial diarrhea in adults, its prevalence in stool cultures sent to hospital microbiology laboratories is not clearly established . Objectives: To determine the prevalence of C difficile in inpatient stools sent to hospital microbiology laboratories and to assess the re lationship between serotypes and toxigenicity of the strains isolated and the clinical data. Methods: From January 18, 1993, to July 31, 199 3, the presence of C difficile was systematically investigated in a ca se-control study on 3921 stool samples sent for stool culture to 11 Fr ench hospital microbiology laboratories. The prevalence of C difficile in this population (cases) was compared with that of a group of 229 r andom hospital controls matched for age, department, and length of sta y (controls). Stool culture from controls was requested by the laborat ory although not prescribed by the clinical staff. Serotype and toxige nesis of the strains isolated were compared. Results: The overall prev alence of C difficile in the cases was twice the prevalence in the con trols (9.7% vs 4.8%; P<.001) and was approximately 4 times as high in diarrheal stools tie, soft or liquid) as in normally formed stools fro m controls (11.5% vs 3.3%; P<.001). The strains isolated from diarrhea l stools were more frequently toxigenic than those isolated from norma lly formed stools. Serogroup D was never toxigenic, and its proportion was statistically greater in the controls than in the cases (45% vs 1 8%; chi(2)=5.2; P<.05). Conversely, serogroup C was isolated only from the cases. Clostridium difficile was mainly found in older patients ( >65 years), suffering from a severe disabling disease, who had been tr eated with antibiotics and hospitalized for more than 1 week in long-s tay wards or in intensive care. Conclusions: This multicenter period p revalence study clearly supports the hypothesis of a common role of C difficile in infectious diarrhea in hospitalized patients. Disease ass ociated with C difficile should therefore be systematically evaluated in diarrheal stools from inpatients.