Ujwal S, Sabeena S, Bhaskar R, D'Souza G, Santhosha D, Auti A, Kumar R, Ramachandran S, Hindol Maity, Aithal A, Bhandari Y, Jazeel A, Arunkumar G
Manipal Institute of Virology, Manipal Academy of Higher Education, Manipal, Karnataka, India.
J Vector Borne Dis. 2019 Jul-Sep;56(3):231-236. doi: 10.4103/0972-9062.289402.
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.
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.
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.
登革热是印度东北部的一个主要公共卫生问题，那里大多数病例未报告且未被诊断。尽管所有四种登革热血清型均有报告，但关于基因多样性的信息却很匮乏。本横断面研究于2016 - 2017年开展，旨在基于包膜（E）糖蛋白基因确定登革热病毒2型（DENV - 2）的基因变异情况。
作为基于医院的急性发热性疾病监测的一部分，收集了印度东北部地区的血清样本并进行血清分型。使用QIAquick® RNA提取试剂盒从DENV - 2血清样本中提取病毒RNA。通过常规逆转录聚合酶链反应（RT - PCR）扩增E基因，并对PCR产物进行测序。
对9份病毒RNA浓度高（Ct <25）的血清样本的E糖蛋白基因进行了测序。来自阿萨姆邦和梅加拉亚邦的8株DENV - 2毒株的E基因序列与IV型（世界流行型）一致，来自特里普拉邦的1株毒株与亚洲 - I型基因型分离。
在流行国家，持续开展基于实验室的监测对于了解登革热的传播动态至关重要。本研究得出结论，在印度东北部，目前有两种不同的DENV - 2基因型在传播，即IVb型（世界流行型）和亚洲 - I型基因型。
