Dengue virus serotypes and genotypic characterization from northeast India

Abstract

Dengue is a rapidly spreading acute arboviral infection transmitted through a human and Aedes mosquito cycle. Though northeast region of India has been experiencing dengue outbreaks regularly for over a decade, reports on genetic characterization of the virus from this region are limited. The present study was undertaken to detect the genotype and genetic composition of circulating dengue virus (DENV) in this region. Blood samples were collected from 918 suspected dengue patients of five northeast Indian states. Serological investigations, viz, nonstructural 1 (NS1) enzyme‐linked immunosorbent assay (ELISA), immunoglobulin M (IgM) ELISA, and immunoglobulin G (IgG) ELISA were performed followed by molecular detection. Sequence analysis and phylogenetic tree construction based on capsid‐premembrane (C‐prM) gene junction was done by BioEdit and MEGA6 software, respectively. Serological detection showed 35.34% NS1 and 18.12% IgM positivity. Secondary infection was observed in 24.53%. All four serotypes were detected. Phylogenetic analysis demonstrated circulation of genotype III of DENV‐1, genotype IV of DENV‐2, and genotype III of DENV‐3. Sequences from this region form distinct clades in the phylogenetic tree. Characterization of the C‐prM gene junction reveals divergence among the DENV strains. As genetic variation within the DENV is known to be associated with diverse clinical outcomes, information regarding the genetic composition of circulating virus could be beneficial in designing an effective intervention strategy.

Incrimination of Aedes aegypti and Aedes albopictus as vectors of dengue virus serotypes 1, 2 and 3 from four states of Northeast India

“…Surveillance in a greater number of mosquito pools over a wider geographical area is required to yield confirmation about the actual status of DENV-4 circulating in the area. Previous studies have also shown that DENV-2 was the predominant serotype in this region and DENV-4, the rarest [ 2 ]. In India as a whole, DENV-4 serotype is not very common and from northeast India, previous reports are confined to Arunachal Pradesh and Manipur [ 2 ].…”

“…Previous studies have also shown that DENV-2 was the predominant serotype in this region and DENV-4, the rarest [ 2 ]. In India as a whole, DENV-4 serotype is not very common and from northeast India, previous reports are confined to Arunachal Pradesh and Manipur [ 2 ]. Moreover, the serotype replacement phenomenon observed in relation to dengue virus might also be responsible for the absence of DENV-4 serotype in the current study [ 2 ].…”

“…In India as a whole, DENV-4 serotype is not very common and from northeast India, previous reports are confined to Arunachal Pradesh and Manipur [ 2 ]. Moreover, the serotype replacement phenomenon observed in relation to dengue virus might also be responsible for the absence of DENV-4 serotype in the current study [ 2 ]. In Meghalaya, only the DENV-2 serotype was observed, which is in concurrence with the DENV serotype recorded in human cases from the state previously [ 2 ].…”

“…Northeast India comprises eight states and except Sikkim, all the other states have reports of DENV activity in the past with the four common serotypes of DENV (DENV-1 to 4) being prevalent in the region [ 2 ].…”

Significance of RANTES‐CCR5 axis and linked downstream immunomodulation in Dengue pathogenesis: A study from Guwahati, India

“…Dengue is a global, national, and a regional issue with a recent report from Northeast India reporting the presence and circulation of all the Dengue serotypes. 33 In the absence of a globally validated vaccine, it is a serious health issue and needs urgent focus and addressing. One of the CCR5 is expressed on monocytes which is a prime site of DENV replication.…”