Epidemiological and molecular typing of dengue viruses circulating in Jorhat district, Assam, India

Dengue is a significant mosquito-borne infection that causes public health concern, particularly in tropical and subtropical regions. This study aimed to characterize the molecular typing of dengue viruses in Jorhat district, as information on dengue serotypes is scarce in India.

A total of 1359 serum samples of clinically suspected dengue cases were tested for non-structural protein 1 (NS1) antigen and Immunoglobulin M (IgM) antibody using enzyme-linked immunosorbent assay (ELISA). Additionally, viral RNA was extracted from positive samples for multiplex reverse transcriptase-polymerase chain reaction (RT-PCR) to determine the dengue serotypes. Seasonal variations, gender, and age-wise incidences were also studied. Statistical analysis was performed to assess demographic and clinical characteristics.

This study depicts a substantial burden of dengue, with 370 (27.22 %) positive samples. IgM and NS1 ELISA tested positive for 42 (11.3 %) and 328 (88.6 %) samples. Dengue virus (DENV) cases predominantly affected males (58.4 %) and the age group of 16-30 years. The major clinical manifestations include fever, headache, and body aches. Serotyping revealed DENV-2 as the predominant serotype, followed by DENV-3 and DENV-1. The co-infection of DENV-2 and DENV-3 was observed in many cases. Seasonal clustering of dengue cases indicates the highest peak in September and October.

This study provides valuable insights into the epidemiology, diagnosis, and serotyping of dengue viruses in the Jorhat district of Assam, emphasizing the need for continued surveillance and effective vector control measures that should be implemented to mitigate the early detection of dengue in this region.