Incidence and characterization of Clostridium difficile in a secondary care hospital in Spain.

INTRODUCTION: Clostridium difficile (C. difficile) is a major nosocomial infectious agent in hospitals. Previous studies have addressed the high proportion of infection episodes that are overlooked in health care facilities. OBJECTIVE: the main aim of this study was to characterize C. difficile clinical cases that occurred in a secondary care hospital during a five-month period. MATERIAL AND METHODS: for this purpose, a total of 137 stool samples from the same number of patients with diarrhea were analyzed for the presence of C. difficile by culture techniques. An enzyme immunoassay (EIA) test for the detection of C. difficile and its toxins was also used in 50 cases (36.5%) for diagnostic purposes. RESULTS: a total of 14 (10.2%) C. difficile isolates were obtained, of which nine (64.3%) were toxigenic. A mean incidence of 3.2 episodes of C. difficile infections (CDI) per 10,000 patients-days was estimated for the study period. Around 56% of the CDI cases were determined as hospital-acquired, whereas 44% originated in the community. Among these, only two episodes (22.2%) were detected in the hospital by the EIA test, which indicated that the hospital CDI detection protocol needed to be revised. One unusual C. difficile isolate was negative for all toxin genes examined and also for the non-toxigenic strain assay, which highlights the need to perform genome sequencing to study its pathogenicity locus insertion site organization. A stable metronidazole-resistant C. difficile strain and three strains showing multidrug resistance were detected in this study, suggesting that C. difficile antimicrobial susceptibility surveillance programs should be established in this health-care facility.