Clinical epidemiology of Clostridium difficile infection among hospitalized patients with antibiotic-associated diarrhea in a university hospital of Brazil.

A cohort of 110 adult individuals was analyzed to compare clinical characteristics of hospitalized patients who received antibiotics and developed Clostridium difficile infection (CDI) with those who received antibiotics and did not develop the disease in a university Hospital in Brazil. CDI was diagnosed by toxigenic culture and C. difficile isolates were characterized by PCR ribotyping. Stool samples were also screened for Clostridium perfringens, methicillin-resistant Staphylococcus aureus (MRSA) and Klebsiella oxytoca. The prevalence of CDI among patients with AAD was 31.8%. C. difficile diarrhea was significantly associated with the severity of underlying comorbidities at admission (OR = 1.21; 95% CI, 1.04-1.40) and with the number of antibiotics used during hospitalization (OR = 1.43; 95% CI, 1.07-1.92). Diabetes mellitus was markedly associated with a higher risk of death in patients with AAD (OR = 6.38; 95% CI, 1.33-30.7). PCR ribotypes 014/020 and 106 (20.6% each) were the most common among the isolates. Binary toxin-encoding gene (cdtB) was detected in six samples, but previously described hypervirulent ribotypes 027 and 078 were not found. K. oxytoca and enterotoxigenic C. perfringens were not detected, while only one patient (0.9%) was positive for MRSA. Our results indicate that comorbidity severity and the number of antibiotics used during hospitalization are strong independent predictors of nosocomial C. difficile diarrhea. Diabetes was associated with a higher mortality among patients with AAD. A huge diversity of C. difficile ribotypes was observed in our study, although classical hypervirulent strains were not observed.