Diagnostic accuracy of tests for leprosy: a systematic review and meta-analysis

Objectives: Owing to difficulties in the clinical diagnosis of leprosy, several complementary tests have been developed and used. The aim was to systematically summarize the accuracy of diagnostic tests for leprosy. Methods: We searched for relevant articles in Embase, Medline, and Global Health databases, until June 2017. Studies evaluating the accuracy of any diagnostic techniques for differentiating between people with and without leprosy were included. Studies solely focusing on differentiating between the separate forms of leprosy were excluded. Our protocol was registered on PROSPERO (CRD42017071803). We assessed study quality using the QUADAS-2 checklist. A bivariate random effects regression model was used for the meta-analyses. Results: We included 78 studies, most of those evaluating the detection of IgM antibodies against phenolic glycolipid I using ELISA. Sensitivity of the 39 studies evaluating ELISA was 63.8% (95% CI 55.0–71.8); specificity 91.0% (95% CI 86.9–93.9). The lateral flow test (nine studies) and the agglutination test (five studies) had a slightly higher sensitivity and a slightly lower specificity. Sensitivity of qPCR was (five studies) 78.5% (95% CI 61.9–89.2) and specificity 89.3% (95% CI 61.4–97.8). Sensitivity of conventional PCR was (17 studies) 75.3% (95% CI 67.9–81.5) and specificity 94.5% (95% CI 91.4–96.5). Conclusions: Although the test accuracy looks reasonable, the studies suffered from heterogeneity and low methodological quality.