Phylogenetic characterization of Dengue virus type 2 in Espírito Santo, Brazil.

Over the last decade, the Espírito Santo State, Brazil has become an endemic Dengue fever location with annual outbreaks of varying magnitude. It is still unclear which geographical route allowed the virus entry in the state and how it has genetically changed since then. Therefore we have set out to study the local molecular constitution of the virus and determine phylogenetic similarities and differences with other Brazilian locations, as well as locations worldwide. Viral envelope genes were partially sequenced from Dengue patients during the 2009 epidemic. We were able to determine that local strains were of American/Asian genotype and closely related to viruses circulating in Rio de Janeiro and São Paulo states during the 2007, 2008 and 2009 epidemics. Genetic divergence analysis showed that the American/Asian genotype is evolutionarily closer to the Asian II genotype and distant from the Sylvatic genotype. Sequenced strains were not 100% similar and showed a high evolutionary conservation of the fusion peptide in the dimerization domain of E protein. This is the first molecular description of circulating Dengue virus strains in the Espírito Santo State, Brazil and should help monitor and control local Dengue outbreaks.