Evaluation of commercial rapid test kits to determine the effective diagnostic method for dengue in a low resource setting

Abstract

Conventional commercially available rapid immuno-chromatographic tests (ICTs) or diagnostic kits were evaluated for their sensitivity, specificity, cost and turnaround time (TAT) results with Dengue IgM/IgG capture enzyme linked immunosorbent assays (ELISA) as the standard test, in blood samples from a cross-section of individuals with clinical features suggestive of dengue fever attending health care facilities in the country. Blood samples taken from over 100 consented participants were analyzed using the two rapid ICTs (SD Bioline Dengue Duo NS1/IgM/IgG and Panbio Dengue Duo Cassette) and compared with the Dengue IgM/IgG capture ELISAs. Standardized questionnaire was used to obtain bio and epidemiological data of the participants. The laboratory evaluation also assessed the TAT to complete the tests as well as the cost for each test method. The laboratory analysis on a given number (n=93) revealed that the SD Bioline was more sensitive (39.9%) than the Panbio (22.1%; p=0.005), and specificities for both were 100%. The SD Bioline includes an extra biomarker test with the same TAT and differs in cost by USD$ 1.14 as opposed to the Panbio. The ELISA has a cost of USD$ 8.07 and despite its longer TAT, it has the advantage of running more samples (1 vs 96) at a given time. While SD Bioline may be the better choice with a higher sensitivity, dengue ELISAs should also be favourably considered as an option for diagnostic purposes. In a resource strapped setting like the laboratories in Trinidad and Tobago, the ELISA should be preferred because its sensitivity and specificity were higher than the Panbio and SD Bioline kits. Besides, more samples were tested giving an effective TAT for amounts of samples completed despite a higher cost.