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Loop-mediated isothermal DNA amplification (LAMP) is currently used as standalone diagnostic test for C. difficile infection (CDI). We assessed the diagnostic accuracy of LAMP for the diagnosis of CDI. We searched 5 databases to identify studies that compared LAMP with culture cytotoxicity neutralization assay or anaerobic toxigenic culture (TC) of C. difficile. We used the random-effects model to calculate pooled sensitivities, specificities, diagnostic odds ratios, and their 95% confidence intervals (CIs). The search of the databases yielded 16 studies (6979 samples) that met inclusion criteria. When TC was used as the gold standard (6572 samples), bivariate analysis yielded a mean sensitivity of 0.95 (95% CI, 0.93-0.97; I(2)=67.4) and a mean specificity of 0.99 (95% CI, 0.96-1.00; I(2)=97.0). LAMP is a useful diagnostic tool with high sensitivity and specificity for detecting CDI. The results should, however, be interpreted only in the presence of clinical suspicion and symptoms of CDI., (Copyright © 2015 Elsevier Inc. All rights reserved.)

Objectives: Antibiotic exposure is the most important risk factor for Clostridium difficile infection (CDI). Most evaluations of antimicrobial risk factors have been conducted in healthcare settings. The objective of this meta-analysis was to evaluate the association between antibiotic exposure and community-associated CDI (CA-CDI) (i.e. symptom onset in the community with no healthcare facility admission within 12 weeks) and to determine the classes of antibiotics posing the greatest risk., Methods: We searched four electronic databases for subject headings and text words related to CA-CDI and antibiotics. Studies that investigated the risk of CA-CDI associated with antibiotic usage were considered eligible. Data from the identified studies were combined using a random-effects model and ORs were calculated., Results: Of 910 citations identified, eight studies (n = 30 184 patients) met our inclusion criteria. Antibiotic exposure was associated with an increased risk of CA-CDI (OR 6.91, 95% CI 4.17-11.44, I(2) = 95%). The risk was greatest with clindamycin (OR 20.43, 95% CI 8.50-49.09) followed by fluoroquinolones (OR 5.65, 95% CI 4.38-7.28), cephalosporins (OR 4.47, 95% CI 1.60-12.50), penicillins (OR 3.25, 95% CI 1.89-5.57), macrolides (OR 2.55, 95% CI 1.91-3.39) and sulphonamides/trimethoprim (OR 1.84, 95% CI 1.48-2.29). Tetracyclines were not associated with an increased CDI risk (OR 0.91, 95% CI 0.57-1.45)., Conclusions: Antibiotic exposure was an important risk factor for CA-CDI, but the risk was different amongst different antibiotic classes. The risk was greatest with clindamycin followed by fluoroquinolones and cephalosporins, whereas tetracyclines were not associated with an increased risk.

Background & Aims: In the past decade, there has been a growing epidemic of Clostridium difficile infection (CDI). During this time, use of proton pump inhibitors (PPIs) has increased exponentially. We evaluated the association between PPI therapy and the risk of CDI by performing a meta-analysis., Methods: We searched MEDLINE and 4 other databases for subject headings and text words related to CDI and PPI in articles published from 1990 to 2010. All observational studies that investigated the risk of CDI associated with PPI therapy and used CDI as an end point were considered eligible. Two investigators screened articles independently for inclusion criteria, data extraction, and quality assessment; disagreements were resolved based on consensus with a third investigator. Data were combined by means of a random-effects model and odds ratios were calculated. Subgroup and sensitivity analyses were performed based on study design and antibiotic use., Results: Thirty studies (25 case-control and 5 cohort) reported in 29 articles met the inclusion criteria (n = 202,965). PPI therapy increased the risk for CDI (odds ratio, 2.15, 95% confidence interval, 1.81-2.55), but there was significant heterogeneity in results among studies (P < .00001). This association remained after subgroup and sensitivity analyses, although significant heterogeneity persisted among studies., Conclusions: PPI therapy is associated with a 2-fold increase in risk for CDI. Because of the observational nature of the analyzed studies, we were not able to study the causes of this association. Further studies are needed to determine the mechanisms by which PPI therapy might increase risk for CDI., (Copyright © 2012 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Background: Current detection methods for Clostridium difficile infection (CDI) can be time-consuming and have variable sensitivities. Real-time polymerase chain reaction (PCR) may allow earlier and more accurate diagnosis of CDI than other currently available diagnostic tests. A meta-analysis was performed to determine the diagnostic accuracy of real-time PCR., Methods: We searched MEDLINE (Pubmed/Ovid) and 4 other online electronic databases (1995-2010) to identify diagnostic accuracy studies that compared PCR with cell culture cytotoxicity neutralization assay (CCCNA) or anaerobic toxigenic culture (TC) of C. difficile. Screening for inclusion, data extraction, and quality assessment were carried out independently by 2 investigators and disagreements resolved. Data were combined by means of a random-effects model, and summary receiver operating characteristic curves and diagnostic odds ratios were calculated., Results: Nineteen studies (7392 samples) met our inclusion criteria. The overall mean sensitivity of PCR was 90% (95% confidence interval [CI]: 88%-91%), specificity 96% (CI: 96%-97%), positive likelihood ratio 26.89 (CI: 20.81-34.74), negative likelihood ratio 0.11 (CI: .08-.15), diagnostic odds ratio 278.23 (CI: 213.56-362.50), and area under the curve 0.98 (CI: .98-.99). Test accuracy depended on the prevalence of C. difficile but not on the reference test used. At C. difficile prevalence of <10%, 10%-20% and >20% the positive predictive value and the negative predictive value were 71%, 79%, 93% and 99%, 98% and 96%, respectively., Conclusions: Real-time PCR has a high sensitivity and specificity to confirm CDI. Overall diagnostic accuracy is variable and depends on CDI prevalence.

Background & Aims: Clostridium difficile infection (CDI) is a hospital-acquired infection with increasing incidence and severity. The most frequently used test to diagnose CDI is an enzyme immunoassay (EIA) for toxins A and B in stool samples. It is common to test 2 or more stool samples, based on the assumption that this detects CDI with greater sensitivity than analysis of 1 sample. We investigated whether repeat stool testing significantly improves the diagnostic yield for CDI., Methods: We performed a retrospective analysis of hospitalized patients who were tested for CDI using EIA. From year 2005 to 2008, 39,402 stool samples from 17,971 patients with 29,373 diarrhea episodes were tested. Transition probabilities were calculated based on results from repeated tests., Results: A total of 2692 diarrheal episodes (9.17%) were diagnosed with CDI. Based on results of 3 consecutive tests, 2675 (99.36%) were diagnosed with CDI. The first stool sample tested produced positive results for 90.7% of cases. When samples were tested consecutively, for the second and third time, an additional 6.6% and 2% patients had positive test results, respectively. If the first test result was negative, the probability of the second test result being positive was 2.7%. If the first 2 test results were negative, the probability of the third test result being positive was 2.3%., Conclusions: In patients who had multiple stool samples tested for CDI by EIA, almost 91% were accurately diagnosed based on the results of a single stool sample alone. Subsequent testing yielded a positive result in only 8.6% of patients. We therefore recommend that repeat testing not be done on a routine basis because it does not significantly improve diagnostic yield., (Copyright © 2011 AGA Institute. Published by Elsevier Inc. All rights reserved.)

Objective: The aim of this brief review is to summarize the literature as it relates to the potential value of repeat stool testing for Clostridium difficile (C. difficile) toxin using an enzyme immunoassay (EIA) for toxin A&B and also propose a potential newer algorithm for diagnosing C. difficile., Research Design and Methods: Two investigators conducted independent literature searches using PubMed, Web of Science, and Scopus until May 1st, 2010. All databases were searched using the terms Clostridium difficile, CDAD, antibiotic associated diarrhea, C. difficile in combination with enzyme immunoassay, enzyme linked immunosorbent assay, Clostridium difficile toxin A, Clostridium difficile toxin B, Clostridium difficile toxin and repeat stool testing. Articles which discussed EIA in C. difficile infection (CDI) patients were reviewed and relevant cross references also read and evaluated for inclusion. Selection bias could be a possible limitation of the approach used in selecting or finding articles for this article., Findings: The evidence for repeat stool testing for C. difficile toxin detection using toxin EIA is becoming weaker. Most recent published practice guidelines recommend a two- or three-step testing algorithm for the detection of C. difficile., Conclusions: EIA for C. difficile stool toxin has a limited sensitivity, but, it does not warrant repeat stool testing. The data for this are suggestive but not conclusive. More studies and better tests are needed to have clear guidelines which can specify the number of tests needed in a diagnostic workup of suspected C. difficile infection. A two-step or three-step method in the diagnosis of C. difficile-associated diarrhea offered a marked increase in sensitivity compared to that of toxin A&B EIA alone.