A comparative study of NS1 and IgM using enzyme-linked immunosorbent assay and immunochromatography test for detection of dengue.

BACKGROUND: Dengue is the most common arboviral infection that spreads by Aedes aegypti and Aedes albopictus mosquitoes, and is quickly gaining prominence as a major mosquito-borne viral disease. One of the major public health issues is dengue fever (DF), which can also cause dengue haemorrhagic fever (DHF) and dengue shock syndrome (DSS). Therefore, this study focused on comparison of dengue antigen non-structural protein (NS1) and immunoglobulin M (IgM) using enzyme-linked immunosorbent assay (ELISA) and immunochromatography test (ICT) for detection of dengue.

METHOD: In a Tertiary Care Hospital (TCH), sociodemographic status of probable dengue cases from February 2021 to February 2022 was studied. The results of the Dengue Antigen NS1 and IgM ICT, Dengue NS1 Microlisa, and Dengue IgM Microlisa were compared in order to determine the effective one at managing patients and preventing complications like DHF and DSS.

RESULTS: In distribution of 100 ICT reactive samples, 50% were NS1 reactive and 50% were IgM reactive. One hundred ICT reactive samples were further processed for IgM antibody capture enzyme-linked immunosorbent assay (MAC-ELISA) for both NS1 and IgM. Sensitivity and specificity of NS1 ICT were 89.3% and 71.4% and that of IgM ICT was 88% and 64.5%. As a result of antigenic cross-reactivity, false positive cases were reported. Platelet count of the patients was correlated with an optical density (OD) value of ELISA for both NS1 and IgM. In the present study, patients having low platelet count showed high OD value.

CONCLUSION: In cases of severe thrombocytopenia (platelet count <50000), early diagnosis by screening ICT and confirmation by ELISA (NS1 and IgM) would reduce the complications like DHF and DSS.