Co-circulation of all the Four Serotype of Dengue Virus in Endemic Region of Saurashtra, Gujarat during 2019-2020 Season

Abstract

Introduction: Dengue has rapidly emerged as a vector - borne viral disease in recent years and also endemic in all continents. The agent of dengue, i.e., dengue viruses, are categorised under the genus Flavivirus, with the four dengue virus serotypes: designated as DENV-1, DENV-2, DENV-3 and DENV-4. These all four serotypes are in circulation either singly, or more than one at the same time. Aim: To study the epidemiological update of dengue with circulating serotype and co-infection in Saurashtra region, Gujarat, India. Materials and Methods: A cross-sectional study was conducted during January 2019 to December 2020 and total samples received were 12,563 which were clinically suspected dengue samples case. After receiving blood samples, serum was separated and proceeded for Dengue NS1Ag (nonstructural protein 1 antigen), and Dengue IgM Ab (Immunoglobulin M antibody). After serological confirmation, 151 samples from different geographical area were selected for Dengue specific Reverse Transcriptase- Polymerase Chain Reaction (RT-PCR) for serotyping. results: Total 4069 (32%) had confirmed dengue positive by Enzyme Linked Immunosorbent Assay (ELISA). The ratio of male cases was higher than female, and in age group 21-35 year (47%). Seasonal trend showed a gradual increase in positivity from June with high peak in October. Circulation of all the four serotypes in area, higher monotypic infection by DENV-1 serotype (41%), followed by DENV-4, DENV-2 and DENV-3. Co-infection of different serotypes were also found. conclusion: The present study concluded that all four serotypes circulate with predominant being DENV-1 type and co-infection of different serotypes in the saurashtra region. Dengue mainly affected adult male population, and seasonal peak during monsoon and post-monsoon period.