What do the guidelines say?
To properly determine if a patient truly has CDI, the American College of Gastroenterology (ACG)1 and the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA)2 guidelines recommend a multistep algorithm comprised of:
A sensitive screening test – GDH or NAAT
• Studies show that GDH and NAAT are equally clinically sensitive in ruling out CDI 3-6
A specific toxin test – A toxin enzyme immunoassay (EIA) test
• Provides excellent clinical specificity
The C. DIFF QUIK CHEK COMPLETE® test simultaneously provides both the GDH and toxin results of a two-step algorithm in a single test. It improves workflow, speeds turnaround time, and offers significant cost savings over a PCR-first algorithm. The C. DIFF QUIK CHEK COMPLETE® test is a complete stand-alone 2-step C. difficile algorithm in one test.
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Perspectives on C. difficile Diagnostics: Insights from the Laboratory, Infection Control, and Clinical Infectious Disease • Roles of the microbiology lab, infection control and prevention, and infectious disease clinicians in C. difficile diagnosis • Clinical and financial implications of C. difficile testing • Impact of C. difficile testing methodologies • Impact of C. difficile reporting changes  |
Why should I use a C. difficile multi-step testing algorithm?
C. difficile infection (CDI) is a toxin-mediated disease. Toxigenic strains of C. difficile can produce toxins A and B. While molecular testing methods such as polymerase chain reaction (PCR) and nucleic acid amplification tests (NAAT) can determine whether a C. difficile strain is capable of producing toxin (i.e. carries the toxin genes), these methods cannot determine whether the toxin is actively produced in the patient’s gut. Toxin gene expression does not happen in about half of cases.7 Toxin causes the disease. Without toxin production, the patient’s symptoms are likely due to another cause, and treating these colonized carriers for CDI may have adverse effects (i.e. increased antibiotic resistance and unnecessary isolation) as well as failure to clear the carriage.8-11
What about my “pre-agreed institutional criteria” for stool testing? That’s the first step in my algorithm, right?
While the 2021 ACG guidelines do not recommend NAAT-only testing for CDI, the 2018 IDSA/SHEA Guidelines do allow it with pre-agreed institutional sample criteria (i.e. ≥ 3 loose or unformed stools in ≤ 24 hours with history of antibiotic exposure). However, the pre-agreed institutional criteria is not part of the testing algorithm and the positive predictive value (PPV) of this approach is lower than that of a two-step algorithm.5
The C. DIFF QUIK CHEK COMPLETE® test is an efficient and clinically relevant testing solution.
Rapid clinical decisions are required for proper treatment of CDI patients, so it is critical to have quick and reliable results for both screening and toxin testing. With both GDH and toxin results in approximately 30 minutes, the C. DIFF QUIK CHEK COMPLETE® test differentiates active infection from colonization in a single cost-effective, clinically relevant test.
1.Kelly CR, Fischer M, Allegretti JR, et al. ACG Clinical Guidelines: Prevention, Diagnosis, and Treatment of Clostridioides difficile Infections [published correction appears in Am J Gastroenterol. 2022 Feb 1;117(2):358]. Am J Gastroenterol. 2021;116(6):1124-1147. doi:10.14309/ajg.0000000000001278
2.McDonald LC, Gerding DN, Johnson S, et al. Clinical Practice Guidelines for Clostridium difficile Infection in Adults and Children: 2017 Update by the Infectious Diseases Society of America (IDSA) and Society for Healthcare Epidemiology of America (SHEA). Clin Infect Dis. 2018;66(7):e1-e48. doi:10.1093/cid/ ciy149
3.Quinn CD, Sefers SE, Babiker W, et al. C. Diff Quik Chek complete enzyme immunoassay provides a reliable first-line method for detection of Clostridium difficile in stool specimens. J Clin Microbiol. 2010;48(2):603-605. doi:10.1128/JCM.01614-09
4.Swindells J, Brenwald N, Reading N, Oppenheim B. Evaluation of diagnostic tests for Clostridium difficile infection. J Clin Microbiol. 2010;48(2):606-608. doi:10.1128/JCM.01579-09
5.Sharp SE, Ruden LO, Pohl JC, Hatcher PA, Jayne LM, Ivie WM. Evaluation of the C. Diff Quik Chek Complete Assay, a new glutamate dehydrogenase and A/B toxin combination lateral flow assay for use in rapid, simple diagnosis of Clostridium difficile disease. J Clin Microbiol. 2010;48(6):2082-2086. doi:10.1128/JCM.00129-10
6.Dubberke ER, Han Z, Bobo L, et al. Impact of clinical symptoms on interpretation of diagnostic assays for Clostridium difficile infections. J Clin Microbiol. 2011;49(8):2887-2893. doi:10.1128/JCM.00891-11
7.Polage CR, Gyorke CE, Kennedy MA, et al. Overdiagnosis of Clostridium difficile Infection in the Molecular Test Era. JAMA Intern Med. 2015;175(11):1792-1801. doi:10.1001/jamainternmed.2015.4114
8.Leekha S, Aronhalt KC, Sloan LM, Patel R, Orenstein R. Asymptomatic Clostridium difficile colonization in a tertiary care hospital: admission prevalence and risk factors. Am J Infect Control. 2013;41(5):390-393. doi:10.1016/j.ajic.2012.09.023
9.Shim JK, Johnson S, Samore MH, Bliss DZ, Gerding DN. Primary symptomless colonisation by Clostridium difficile and decreased risk of subsequent diarrhoea. Lancet. 1998;351(9103):633-636. doi:10.1016/S0140-6736(97)08062-8
10.Kyne L, Warny M, Qamar A, Kelly CP. Asymptomatic carriage of Clostridium difficile and serum levels of IgG antibody against toxin A. N Engl J Med. 2000;342(6):390-397. doi:10.1056/NEJM200002103420604
11.Fishbein SRSHink T, Reske KA, Cass C, Struttmann E, Iqbal ZH, Seiler S, Kwon JH, Burnham CDDantas G, Dubberke ER. 2021. Randomized Controlled Trial of Oral Vancomycin Treatment in Clostridioides difficile-Colonized Patients. mSphere 6:10.1128/msphere.00936-20. https://doi.org/10.1128/msphere.00936-20