Systematic review: Accuracy of diagnostic methods for Clostridioides difficile infection

To analyze the accuracy of diagnostic methodologies for Clostridioides difficile infection (CDI).

A systematic review was conducted in Medline, Embase, and Lilacs (July 2024). Studies with patients suspected of CDI using any diagnostic method (TC [toxigenic culture], LA [latex agglutination], CCNA [cell cytotoxicity neutralization assay], EIA [enzyme immunoassay], or NAAT [nucleic acid amplification test]) were included. Studies qualities were assessed using QUADAS-2 and QUADAS-C (Quality Assessment of Diagnostic Accuracy Studies - 2 and Comparative Accuracy), and evidence quality using GRADE (Grading of Recommendations Assessment, Development and Evaluation). Meta-analysis (MA) was performed considering central value and 95% confidence interval. This study was registered in PROSPERO (CRD42021234898) and supported by CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil).

170 studies were included, 79 entered the MA, covering at least 98,786 stool samples. Studies evaluated several methodologies, such as TC; EIA for GDH (glutamate dehydrogenase), GDH and toxin A, GDH and toxin AB, EIA for toxin A or toxin AB; molecular tests like NAAT for toxin A, toxin AB, toxin B and ribotype 027, toxin B/Bi and ribotype 027, toxin A/B/Bi and ribotype 027, toxin B and LA. TC was the most commonly used reference test (93.5%). MA showed variability among methods. Molecular biology methodologies were favored for identifying toxins A and B, with significant accuracy. EIA for GDH was an effective screening method (sensitivity: 91.599% [89.149 - 94.049]).

CDI detection presents challenges without defined gold standard. EIA and NAAT revolutionized diagnostics, offering high accuracy, and faster diagnosis.