Simultaneous use of two rapid diagnostic tests for the diagnosis of Chagas disease

Abstract

The sensitivity of rapid diagnostic tests (RDT) for Chagas disease is not great enough for their single use. The aim of this paper was to evaluate the performance of two RDTs for Chagas disease, used simultaneously. Two different RDTs (A and B) were performed in 64 and 42 serum samples that were negative and positive, respectively, by conventional serological techniques. Validity and reliability of both tests were evaluated individually and simultaneously. Sensitivity was 90.5% and 97.6%, and specificity was 100% and 93.8%, for RDT A and B, respectively. The k statistic was 0.96. When both RDTs were used simultaneously, sensitivity was 97.4%, specificity was 100% and the discordance percentage 6.6%. The combined use of two RDTs with serum samples is an acceptable application in healthcare centres.

Rapid Diagnostic Tests for Trypanosoma cruzi Infection: Field Evaluation of Two Registered Kits in a Region of Endemicity and a Region of Nonendemicity in Argentina

“…We must point out that the accuracy parameters of both the SD and WL tests were lower than those indicated by the manufacturers, as already evidenced in other studies (1, [8][9][10][11][12][13][14][15][16][17][18]27).…”

“…The field evaluation of the RDTs SD and WL showed that these tests had higher sensitivity and specificity than other ChD RDTs evaluated previously in different countries and using different samples (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18). When these RDTs were performed with serum samples, they on October 29, 2020 by guest http://jcm.asm.org/ Downloaded from showed a sensitivity of about 96% to 100% (13,14,18,19), but when they were performed with whole blood samples, their sensitivity decreased between to 96 to 62.5% (15,18).…”

“…In all cases, results of RDTs must be confirmed by other more specific serological tests or molecular biology techniques. Numerous studies have analyzed the performance of RDTs specific for ChD in different populations and with different samples, finding high variability in performance, with sensitivity values ranging from 33 to 100% and specificity values ranging from 94 to 99.9% (8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19).…”

Use of rapid diagnostic tests (RDTs) for conclusive diagnosis of chronic Chagas disease – field implementation in the Bolivian Chaco region

“…Various studies have previously described they can provide very good sensitivity and specificity, even working with tiny volumes of whole blood [19–22]. Furthermore, the combined use of two RDTs has already been suggested as a substitute of the current algorithm based on conventional serological methods [19, 23]. In the present study we demonstrate that the field use of RDTs by mobile teams could indeed substitute the use of conventional tests in the highly endemic Chaco region of Bolivia.…”

Rapid diagnostics test for detecting Chagas disease - Breaking barriers to diagnosis access in remote areas

“…These characteristics make them very useful as screening tests in distant sites; however, a positive result must be confirmed later in a laboratory by CST. The low sensitivity values obtained with RDT by different authors suggest that they would be useful only if used in parallel with a CST, rendering them less useful in the field [14][15][16]. Diagnosis sensitivity can be enhanced by performing tests simultaneously on a single sample.…”