Molecular Characterization and Phylogenetic Analysis of Circulating Dengue Virus

Abstract

Background: Dengue fever (DF) is one of the most important arboviral infection, newlinetransmitted to humans through the bites of infected Aedes mosquitoes, principally Aedes newlineaegypti. It is caused by dengue virus (DENV), which belongs to the genus Flavivirus newline(family Flaviviridae). It is the enveloped virus containing single stranded positive sense newlineRNA of nearly 11 kb length. The genomic organization consists of three structural newline(capsid, C; membrane, M; and envelope, E) and seven non-structural (NS1, NS2A, newlineNS2B, NS3, NS4A, NS4B and NS5) genes flanked by untranslated region (UTR) at 5 newlineand 3 ends. newlineThe DENV exists as four distinct antigenic groups or serotypes namely; DENV- newline1,2,3 and 4. Infection with any one serotype may lead to a mild, self limiting febrile newlineillness; classical dengue fever (DF). A few cases of DF may also lead to severe, life newlinethreatening dengue hemorrhagic fever (DHF) and dengue shock syndrome (DSS). newlineSubstantial genetic variations in the already existing serotype also known to exist due to newlinewhich serotypes are further classified into distinct genotypes; some having restricted newlinegeographical distribution, while others being cosmopolitan, reflecting their distribution newlineacross the tropical world. The genomic variations below the level of genotype also newlineexists which can be observed in the form of phylogenetically distinct clades or lineages. newlineThe studies of clades/lineages, have great implication in understanding the evolutionary newlineprocess of DENV. newlineDengue, once considered a neglected tropical disease, affecting the people of newlinedeveloping nations, is now emerging as a global public health concern. The disease is newlineendemic in many countries of Africa, the Americas, the Eastern Mediterranean, newlineSoutheast Asia and the Western Pacific. Approximately 2.5 billion people living in newlinetropical and sub-tropical areas are at the risk of infection which is approximately 40% newlineof the world s population. In the last 50 years, up-to 30-fold increase in disease newlineprevalence has been observed. Southeast Asia is one of the most important epi...