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.

Impact of simultaneous glutamate dehydrogenase and toxin A/B rapid immunoassay on Clostridium difficile diagnosis and treatment in hospitalized patients with antibiotic-associated diarrhea in a university hospital of Brazil.

BACKGROUND AND AIM: Clostridium difficile is a major cause of health care-associated infection, but disagreement between diagnostic tests is an ongoing barrier to clinical decision-making. Conventional enzyme immunoassay (EIA) for toxin detection is currently the most frequently used technique for C. difficile infection (CDI) diagnosis, but its low sensitivity makes the development of an alternative strategy necessary for improving the diagnosis in developing countries. METHODS: Between years 2011 and 2015, 154 stool samples from patients with antibiotic-associated diarrhea were examined by toxigenic culture and EIA for the diagnosis of CDI. In the year 2015, when glutamate dehydrogenase (GDH) test was first available in Brazil, 53 of those fecal specimens were also tested by the C. diff Quik Chek Complete rapid immunoassay. At this time, we prospectively assessed the impact of this test on CDI treatment rates before and after it was introduced in clinical practice. RESULTS: The GDH component of C. diff Quik Chek Complete test had a sensitivity of 100% and specificity of 95.1% compared with toxigenic culture, with 89.8% concordance. The Tox A/B II EIA and the toxin portion of C. diff Quik Chek Complete yielded sensitivities between values of 50-58.3%, with 100% specificities. The introduction of GDH test increased the number of treated patients with CDI from 57.7% to 100%. CONCLUSIONS: Glutamate dehydrogenase test is a reliable method for the diagnosis of CDI and greatly increases the number of properly treated patients with CDI. Therefore, this exam should be considered the mainstay for the laboratory diagnosis of CDI in developing countries.