A Study on Seroprevalence of Dengue Infection in a Tertiary Care Centre and Role of Rapid NS1 Antigen Test in Early Diagnosis

INTRODUCTION Dengue virus infection is one of the most important vector-borne human arboviral infection and has emerged as a notable public health problem in recent decades. AIMS To study the trend of seroprevalence of dengue infection and to highlight the usefulness of rapid NS1 antigen test in early diagnosis of dengue. MATERIALS AND METHOD A retrospective study was done in the Department of Microbiology of a tertiary care centre during the study period of October to December in the year 2017, 2018 and 2019. The serum samples were subjected to immuno-chromatographic Dengue NS1 antigen, IgM / IgG Antibodies rapid kit test and Dengue IgM Mac ELISA test. RESULTS In October to December 2019, 1138 samples of suspected dengue cases were sent to our lab for detection by rapid kit tests. Out of which 161 (14.1%) samples were NS1 positive , 38 (3.3%) were only IgM positive and 4 (0.4%) were IgG positive . We received 107 samples for Dengue IgM MAC Elisa of which 28 (26.2%) were positive and 25 (23.4%) were equivocal. In October to December 2018, 285 samples were received for detection by rapid kit tests .Out of which 16 (5.6%) samples were NS1 positive, 11 (3.9%) were only IgM positive and 17 (6.6%) were IgG positive ; and 158 samples for IgM MAC Elisa of which 26 (16.5%) were positive and 23 (14.6%) were equivocal. In October to December 2017, out of a total of 165 samples for detection by rapid kit tests ; 18 (10.9%) samples were NS1 positive, 19 (11.5%) were only IgM positive and 5 (3%) were IgG positive; and 261 samples for IgM MAC Elisa of which 21 (0.1%) were positive and 21 (0.1%) were equivocal. CONCLUSION This study reported an increasing trend in seroprevalence of Dengue virus which affected many people in recent years and also highlights that the availability of commercial dengue NS1 antigen test kits has provided an additional laboratory diagnostic tool for early detection of Dengue.