EVALUATION OF NS1 ANTIGEN-CAPTURE ELISA AND IgM ANTIBODY CAPTURE ELISA IN ACUTE CASES OF DENGUE IN RURAL POPULATION IN A TERTIARY CARE TEACHING HOSPITAL IN WESTERN UTTAR PRADESH INDIA

Background: Dengue is a major public health problem in resource-limited countries like India. There has always been a quest for best serological test for prompt and accurate diagnosis and whether single test or a combination be used. Enzyme immunoassays based on the detection of dengue virus non-structural protein 1 (NS1), and IgM antibody capture are available with different sensitivities and specificities observed in various settings. Aim: Diagnostic efficacies of two enzyme immunoassays, i.e. non-structural 1 (NS1) antigen-capture ELISA against IgM antibody capture ELISA to confirm cases of dengue infection in single acute serum samples have been evaluated and each test compared against the combination of the two. Material and methods: NS1 antigen (QUALISA Dengue NS1) and IgM capture ELISA (Calbiotech Dengue Virus IgM ELISA) were performed on 254 single acute serum and interpreted as per the manufacturer’s instructions. Results: The NS1 antigen detection and IgM antibody ELISA gave 25.59% and 17.3% positivity rates, respectively. The combination of two assays increased the overall detection rates to 30.7%. Noteworthy here is, that detection rate improved significantly to 55.72% (McNemar, p< 0.05) when two assays were combined together as compared to each test alone. The two tests together detected positive 34 and 13 samples more than those detected by IgM capture and NS1 Antigen capture ELISA alone respectively. Conclusion: The detection rate increases significantly when both NS1 and IgM tests are combined and this can prove helpful in diagnosis and better management of the cases.