Changes in Dengue virus (DENV) disease patterns in the Americas over recent decades have been attributed, at least in part, to repeated introduction of DENV strains from other regions, resulting in a shift from hypoendemicity to hyperendemicity. Using newly sequenced DENV-1 and DENV-3 envelope (E) gene isolates from 11 Caribbean countries, along with sequences available on GenBank, we sought to document the population genetic and spatiotemporal transmission histories of the four main invading DENV genotypes within the Americas and investigate factors that influence the rate and intensity of DENV transmission. For all genotypes, there was an initial invasion phase characterized by rapid increases in genetic diversity, which coincided with the first confirmed cases of each genotype in the region. Rapid geographic dispersal occurred upon each genotype's introduction, after which individual lineages were locally maintained, and gene flow was primarily observed among neighboring and nearby countries. There were, however, centers of viral diversity (Barbados, Puerto Rico, Colombia, Suriname, Venezuela, and Brazil) that were repeatedly involved in gene flow with more distant locations. For DENV-1 and DENV-2, we found that a "distance-informed" model, which posits that the intensity of virus movement between locations is inversely proportional to the distance between them, provided a better fit than a model assuming equal rates of movement between all pairs of countries. However, for DENV-3 and DENV-4, the more stochastic "equal rates" model was preferred.

Original publication

DOI

10.1093/molbev/msr320

Type

Journal article

Journal

Mol Biol Evol

Publication Date

06/2012

Volume

29

Pages

1533 - 1543

Keywords

Bayes Theorem, Central America, Dengue, Dengue Virus, Disease Outbreaks, Evolution, Molecular, Genotype, History, 20th Century, History, 21st Century, Humans, Models, Genetic, Molecular Typing, Phylogeography, Population Dynamics, Prevalence, Sequence Analysis, DNA, South America, Viral Envelope Proteins, West Indies