Circulation of Asian-I and Cosmopolitan genotypes of Dengue-2 virus in northeast India, 2016-2017.
J Vector Borne Dis 2020;
56:231-236. [PMID:
32655072 DOI:
10.4103/0972-9062.289402]
[Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
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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