Sensitivity and Specificity of two rapid tests for the diagnosis of infection by Trypanosoma cruzi in a Colombian population

Abstract

Objective To evaluate diagnostic precision of two rapid diagnostic tests (RDT’s) on patients with chronic Chagas disease. Methodology Prospective study with the following inclusion criteria: subjects older than 3 years, signed informed consent. Exclusion criterion: subjects could not have previously received treatment for infection with T. cruzi. The study population were participants in a screening process undertaken in rural and urban zones of the department Boyacá, Colombia. Two RDT’s were performed to all participants: the Chagas Detect Plus InBios (CDP) and the Chagas Stat-Pak (CSP) and as a reference standard the ELISA Chagas III GrupoBios and the Chagas ELISA IgG+IgM I Vircell tests were used. In the case of discordant results between the two ELISA tests, an indirect immunofluorescence was done. Results Three hundred-five (305) subjects were included in the study (38 patients with leishmaniasis), of which 215 tested negative for T cruzi and 90 tested positive according to the reference standard. The sensitivity of the RDT’s were 100% (CI 95% 95.9–100), and the specificity of the CDP was 99.1% (CI 95% 96.6–99.8) and for CSP was 100% (CI 95% 98.3–100). The agreement of CDP was 99.5% and for CSP was 100% with Kappa values of (k = 99.1; CI 95% 92.6–99.8%) and (k = 100; CI 95% 94.3–100), respectively. RDT’s did not present cross-reactions with samples from patients who were positive for leishmaniasis. Conclusions The findings demonstrate excellent results from the RDT’s in terms of validity, safety, and reproducibility. The results obtained provide evidence for the recommendation for using these tests in a Colombian epidemiological context principally in endemic areas in which laboratory installations necessary to perform conventional tests are not available, or they are scarce and to help in diagnosing chronic Chagas disease in order to provide access to treatment as soon as possible.

Biomarkers for the diagnosis, treatment follow‐up, and prediction of cardiac complications in Chagas disease in chronic phase: Recent advances

“…Although rapid tests have a high sensitivity rate of almost 100%, there have been significant variations in their performance in Mexico and the USA due to differences in circulating DTUs in each region 46 . Rapid tests have shown outstanding performance in countries like Colombia and Bolivia 47,48 . To accurately diagnose infections, it is important to develop targeted diagnostic tests for the circulating DTUs in each region.…”

Upconverting phosphor technology-based lateral flow assay for the rapid and sensitive detection of anti-Trichinella spiralis IgG antibodies in pig serum

“…Data were entered into Origin 2020b and are presented as histograms. The kappa ( K ) coefficient was employed to measure agreement between two methods, which allowed us to measure agreement beyond what was expected by chance alone [ 32 , 33 ]. The generic formula for K is where P o and P e are the observed and expected proportions of agreement [ 34 ].…”

Rapid Test and Chagas Disease: An Overview

“…However, to follow the recommended diagnosis algorithm, positive cases still must be confirmed by a conventional immunoassay [31]. In this sense, studies have shown promising results regarding the synchronous combination of two rapid tests with different antigen composition as an alternative strategy for definitive diagnosis in low-resources settings in Bolivia, Argentina, and Colombia [28,31,[34][35][36][37]. The association of two rapid tests displayed ≥93.3% of diagnostic efficiency when using results obtained by at least two conventional immunoassays as reference [28,31,35,36].…”

“…In this sense, studies have shown promising results regarding the synchronous combination of two rapid tests with different antigen composition as an alternative strategy for definitive diagnosis in low-resources settings in Bolivia, Argentina, and Colombia [28,31,[34][35][36][37]. The association of two rapid tests displayed ≥93.3% of diagnostic efficiency when using results obtained by at least two conventional immunoassays as reference [28,31,35,36]. This alternative protocol has a great advantage in speeding up the process of patient continued medical assistance, especially regarding the offer of trypanocidal drugs and, eventually, other necessary treatments.…”

“…As previously mentioned, parasite and/or host genetic background may be related to reactivity discrepancy. Thereby, it is strongly suggested that the rapid test is field validated in the area of interest before officially incorporating its use [31,35]. This process should ideally be carried out at a national level by encompassing different sites [31], once circulating strains may vary from one region to another within the endemic countries [24,25].…”