A Superior Test for Diagnosis of Clostridium difficile-Associated Diarrhea in Resource-Limited Settings

Abstract

SUMMARY:In this prospective cohort study, we investigated the prevalence of Clostridium difficileassociated diarrhea (CDAD) in adult patients with nosocomial diarrhea by performing enzyme immunoassay (EIA) for detecting toxins A and B and polymerase chain reaction (PCR) for detecting the presence of the tcdB gene in stool samples. We determined the factors associated with CDAD, and the treatment outcome of CDAD from May 2010 to January 2011. A total of 175 stool samples were tested by EIA and PCR. In total, 26.9z patients tested positive for C. difficile: 12.6z by EIA and 24.0z by PCR. The kappa coefficient and total agreement of both the tests were 0.46 and 83.2z, respectively. Onset of diarrhea after antibiotic administration for 10 days or more (OR, 2.71; 95z CI, 1.14-6.44; P ＝ 0.024) and leukocyte count À15,000 cells/mm 3 (OR, 3.12; 95z CI, 1.24-7.88; P ＝ 0.016) were significantly associated with occurrence of CDAD. The non-response rate to CDAD treatment was 24.1z, and the all-cause mortality rate was 31.9z in the CDAD group as against 35.9z in the non-CDAD group (P ＝ 0.721). In our study, the performance of direct PCR of stool samples for detecting tcdB was better, with the number of positive results for stool toxins A and B being twofold higher than that in the case of EIA. Patients who have diarrhea after receiving antibiotics for 10 days or more or those who have a leukocyte count of À15,000 cells/mm 3 should be investigated for CDAD.

Evaluation of Multiplex PCR with Enhanced Spore Germination for Detection ofClostridium difficilefrom Stool Samples of the Hospitalized Patients

“…Of 54 PCR-positive samples, 7 were tcdA +    tcdB +    cdtA / B + , 13 were tcdA +    tcdB +    cdtA / B − , 30 were tcdA −    tcdB +    cdtA / B − , and 4 were tcdA −    tcdB +    cdtA / B − . Although, there are previous reports on C. difficile toxin types in Thailand [24, 25], this is the first time that the tcdA +    tcdB +    cdtA / B + isolates were detected. It is also noteworthy that PCR detection of C. difficile toxin genes might only detect DNA without the presence of toxin production; therefore, the PCR-positive cases should be carefully interpreted.…”

Prevalence and molecular epidemiology of Clostridium difficile infection in Thailand

“…Toxigenic culture, which is a current reference standard for C. difficile detection, is rarely performed these days because of time and cost constraints, while the use of PCR-based techniques has increased over the years [7]. In addition to a lack of an optimal detection method, the most recent prevalence study was conducted between 2010 and 2011 [10] and the most recent molecular epidemiologic study between 2006 and 2008 [9].…”

Epidemiology of Clostridium difficile infection in Asia

“…Similarly, a recent study in Bangkok found that combining toxin EIAs with direct tcdB PCR on stool increased positive diagnoses two-fold, compared with toxin EIAs alone [54]. …”