Investigating the molecular evolution of DENV-2 in Malaysia: Analyzing DENV-2 envelope gene sequences from 1987-2018 to understand the mechanisms that drive recurring outbreaks through phyogenetic analysis.
In Malaysia, dengue is hyperendemic with recurrent outbreaks occurring since 1980s. Dengue virus type-2 (DENV-2) is one of the predominant serotypes causing the recurring outbreaks with an increase in the number of cases. This study aimed to investigate the evolutionary dynamics driving the DENV-2 recurring outbreaks over the past three decades. Two hundred and three Malaysian DENV-2 isolates from 1987-2018 were isolated from dengue patient sera retrieved from the WHOCC for Arbovirus Reference & Research depository at TIDREC, University Malaya. The DENV-2 RNA was extracted and amplified for the envelope (E) gene by RT-PCR assay. The complete E gene was sequenced, and the sequences obtained were subjected to phylogenetic and mutational analyses. Our Bayesian maximum clade credibility tree revealed two circulating DENV-2 genotypes in Malaysia: Cosmopolitan and Asian I.