Rapid diagnostic tests and ELISA for diagnosing chronic Chagas disease: Systematic revision and meta-analysis

Objective: To determine the diagnostic validity of the enzyme-linked immunosorbent assay (ELISA) and Rapid Diagnostic Tests (RDT) among individuals with suspected chronic Chagas Disease (CD). Methodology: A search was made for studies with ELISA and RDT assays validity estimates as eligibility criteria, published between 2010 and 2020 on PubMed, Web of Science, Scopus, and LILACS. This way, we extracted the data and assessed the risk of bias and applicability of the studies using the QUADAS-2 tool. The bivariate random effects model was also used to estimate the overall sensitivity and specificity through forest-plots, ROC space, and we visually assessed the heterogeneity between studies. Meta-regressions were made using subgroup analysis. We used Deeks’ test to assess the risk of publication bias. Results: 43 studies were included; 27 assessed ELISA tests; 14 assessed RDTs; and 2 assessed ELISA and RDTs, against different reference standards. 51.2 % of them used a non-comparative observational design, and 46.5 % a comparative clinical design (“case-control” type). High risk of bias was detected for patient screening and reference standard. The ELISA tests had a sensitivity of 99% (95% CI: 98–99) and a specificity of 98% (95% CI: 97–99); whereas the Rapid Diagnostic Tests (RDT) had values of 95% (95% CI: 94–97) and 97% (95% CI: 96–98), respectively. Deeks’ test showed asymmetry on the ELISA assays. Conclusions: ELISA and RDT tests have high validity for diagnosing chronic Chagas disease. The analysis of these two types of evidence in this systematic review and meta-analysis constitutes an input for their use. The limitations included the difficulty in extracting data due to the lack of information in the articles, and the comparative clinical-type design of some studies. Author summary: Chagas disease (CD), an infection caused by the Trypanosoma cruzi parasite, affects between 8 and 10 million people worldwide. It is considered one of the main problems of public health in Latin America, and the international migration has caused infected subjects to scatter through the rest of the world, making CD a global health problem. Therefore, it is important to diagnose this infection using laboratory tests, which sometimes becomes a problem due to lack of reference tests and the existence of different types of tests with different sensitivity and specificity values, added to the difficulty in detecting the parasite in its chronic phase. This systematic review and meta-analysis determined the diagnostic validity of the enzyme-linked immunosorbent assay (ELISA) and rapid diagnostic tests (RDT) among individuals with suspected chronic CD. It included 43 studies and concluded that both ELISA and RDTs had adequate diagnostic performance. It is necessary to better understand these two types of diagnostic tests to facilitate clinical decision making about the disease and improve access to treatment for the population at risk.