Journal of Vector Borne Diseases (Jan 2019)

Circulation of Asian-I and Cosmopolitan genotypes of Dengue-2 virus in northeast India, 2016–2017

  • S Ujwal,
  • S Sabeena,
  • R Bhaskar,
  • G D'Souza,
  • D Santhosha,
  • A Auti,
  • R Kumar,
  • S Ramachandran,
  • Maity Hindol,
  • A Aithal,
  • Y Bhandari,
  • A Jazeel,
  • G Arunkumar

DOI
https://doi.org/10.4103/0972-9062.289402
Journal volume & issue
Vol. 56, no. 3
pp. 231 – 236

Abstract

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Background & objectives: Dengue is a major public health problem in northeast India where the majority of the cases go unreported and undiagnosed. Even though all four dengue serotypes are reported, there is a dearth of information on genetic diversity. The present cross-sectional study was undertaken during 2016–17 to determine the genetic variance of dengue virus serotype 2 (DENV-2) based on the envelope (E) glycoprotein gene. Methods: The serum samples collected from the northeast parts of India, as a part of hospital-based acute febrile illness surveillance, were serotyped. Viral RNA was extracted from DENV-2 serum samples using QIAquick® RNA Extraction Kit. The E gene was amplified by conventional reverse-transcriptase polymerase chain reaction (RT-PCR) and the PCR products were sequenced. Results: The E glycoprotein gene of nine serum samples with high viral RNA concentration (Ct <25) was sequenced. The E gene sequences of eight DENV-2 strains from Assam and Meghalaya aligned with genotype IV (Cosmopolitan) and one strain from Tripura segregated with Asian-I genotype. Interpretation & conclusion: Ongoing laboratory-based surveillance is mandatory to understand the transmission dynamics of dengue in endemic countries. This study concluded that in northeast India, presently two distinct genotypes of DENV-2, namely genotype IVb (Cosmopolitan) and Asian-I genotype are in circulation.

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