title: Diagnostic reliability of an immunochromatographic test for Chagas disease screening at a primary health care centre in a rural endemic area.
abstract: Many patients with Chagas disease live in remote communities that lack both equipment and trained personnel to perform a diagnosis by conventional serology (CS). Thus, reliable tests suitable for use under difficult conditions are required. In this study, we evaluated the ability of personnel with and without laboratory skills to perform immunochromatographic (IC) tests to detect Chagas disease at a primary health care centre (PHCC). We examined whole blood samples from 241 patients and serum samples from 238 patients. Then, we calculated the percentage of overall agreement (POA) between the two groups of operators for the sensitivity (S), specificity (Sp) and positive (PPV) and negative (NPV) predictive values of IC tests compared to CS tests. We also evaluated the level of agreement between ELISAs and indirect haemagglutination (IHA) tests. The readings of the IC test results showed 100% agreement (POA = 1). The IC test on whole blood showed the following values: S = 87.3%; Sp = 98.8%; PPV = 96.9% and NPV = 95.9%. Additionally, the IC test on serum displayed the following results: S = 95.7%; Sp = 100%; PPV = 100% and NPV = 98.2%. Using whole blood, the agreement with ELISA was 96.3% and the agreement with IHA was 94.1%. Using serum, the agreement with ELISA was 97.8% and the agreement with IHA was 96.6%. The IC test performance with serum samples was excellent and demonstrated its usefulness in a PHCC with minimal equipment. If the IC test S value and NPV with whole blood are improved, then this test could also be used in areas lacking laboratories or specialised personnel.
authors.affiliation: Centre for Research on National Endemics, Faculty of Biochemistry and Biological Sciences, National University of Litoral, Santa Fe, Argentina.
authors.forename: Diego
authors.initials: D
authors.lastname: Mendicino
authors.affiliation: Centre for Research on National Endemics, Faculty of Biochemistry and Biological Sciences, National University of Litoral, Santa Fe, Argentina.
authors.forename: Mariana
authors.initials: M
authors.lastname: Stafuza
authors.affiliation: Centre for Research on National Endemics, Faculty of Biochemistry and Biological Sciences, National University of Litoral, Santa Fe, Argentina.
authors.forename: Carlina
authors.initials: C
authors.lastname: Colussi
authors.affiliation: Centre for Research on National Endemics, Faculty of Biochemistry and Biological Sciences, National University of Litoral, Santa Fe, Argentina.
authors.forename: Mónica del
authors.initials: Md
authors.lastname: Barco
authors.affiliation: Centre for Research on National Endemics, Faculty of Biochemistry and Biological Sciences, National University of Litoral, Santa Fe, Argentina.
authors.forename: Mirtha
authors.initials: M
authors.lastname: Streiger
authors.affiliation: National Coordination for Vector Control, Faculty of Medical Sciences, National University of Cordoba, Cordoba, Argentina.
authors.forename: Edgardo
authors.initials: E
authors.lastname: Moretti
mesh_terms: D001118:Argentina / Q000453:epidemiology; D014355:Chagas Disease / Q000097:blood / Q000175:diagnosis* / Q000453:epidemiology; D002846:Chromatography, Affinity; D002855:Chromatography, Thin Layer; D019353:Endemic Diseases; D004797:Enzyme-Linked Immunosorbent Assay; D006386:Hemagglutination Tests; D006801:Humans; D059232:Laboratory Personnel; D011237:Predictive Value of Tests; D011320:Primary Health Care; D015203:Reproducibility of Results; D019035:Rural Health Services; D012424:Rural Population