Molecular Characterization and Serological Analysis of Dengue Virus in Haryana: A Single Hospital-Based Surveillance Study

Abstract

Dengue fever is a serious public health concern, prevalent in tropical and subtropical areas. It is caused by one of the four serotypes of dengue virus i.e., DENV-1, DENV-2, DENV-3, and DENV-4, which are genetically distinct but antigenically similar. Infection with any of the dengue serotypes causes the same disease, which shows up in varying degree of severity. There is a lack of knowledge concerning the circulating serotypes of dengue virus prevalent annually in the peri-urban NCR region. Thus, the present study aimed to determine the seroprevalence and the predominant circulating serotype of dengue virus strains in the peri-urban area of Northwest India. Whole blood collected from dengue suspected patients were assessed for NS1 antigen and/or dengue-specific IgM antibodies by ELISA, based on the duration of fever at the time of sampling. All the NS1 antigen positive samples were subjected to serotyping through a single-step RT-PCR method. Out of 889 suspected cases of dengue, 254 (28.6%) were positive for dengue either by NS1 antigen or IgM antibody or both. A total of 202 NS1 antigen positive cases were identified, of which serotyping could be determined for 154 samples, comprising of DEN-2 (26%), DENV-3 (52,6%) and DENV-4 (21.4%). Our study found DENV-2 and DENV- 3 to be have a positive association with frequency of clinical manifestations and also with disease severity. Patients infected with these serotypes may develop significant problems later in illness. This emphasises the necessity of dengue virus serotyping to monitor patients and handle severe infections faster.