Araújo Josélio M G, Nogueira Rita M R, Schatzmayr Hermann G, Zanotto Paolo M de A, Bello Gonzalo
Laboratory of Flavivirus, Oswaldo Cruz Institute-FIOCRUZ, Rio de Janeiro, Brazil.
Infect Genet Evol. 2009 Jul;9(4):716-25. doi: 10.1016/j.meegid.2008.10.005. Epub 2008 Oct 25.
In this study, we revisited the phylogeography of the three of major DENV-3 genotypes and estimated its rate of evolution, based on the analysis of the envelope (E) gene of 200 strains isolated from 31 different countries around the world over a time period of 50 years (1956-2006). Our phylogenetic analysis revealed a geographical subdivision of DENV-3 population in several country-specific clades. Migration patterns of the main DENV-3 genotypes showed that genotype I was mainly circumspect to the maritime portion of Southeast-Asia and South Pacific, genotype II stayed within continental areas in South-East Asia, while genotype III spread across Asia, East Africa and into the Americas. No evidence for rampant co-circulation of distinct genotypes in a single locality was found, suggesting that some factors, other than geographic proximity, may limit the continual dispersion and reintroduction of new DENV-3 variants. Estimates of the evolutionary rate revealed no significant differences among major DENV-3 genotypes. The mean evolutionary rate of DENV-3 in areas with long-term endemic transmissions (i.e., Indonesia and Thailand) was similar to that observed in the Americas, which have been experiencing a more recent dengue spread. We estimated the origin of DENV-3 virus around 1890, and the emergence of current diversity of main DENV-3 genotypes between the middle 1960s and the middle 1970s, coinciding with human population growth, urbanization, and massive human movement, and with the description of the first cases of DENV-3 hemorrhagic fever in Asia.
在本研究中，我们重新审视了三种主要登革热病毒3型（DENV-3）基因型的系统地理学，并基于对从全球31个不同国家在50年时间（1956 - 2006年）内分离出的200个毒株的包膜（E）基因的分析，估算了其进化速率。我们的系统发育分析揭示了DENV-3种群在几个特定国家分支中的地理细分。主要DENV-3基因型的迁移模式表明，基因型I主要局限于东南亚和南太平洋的沿海地区，基因型II停留在东南亚的大陆区域，而基因型III则传播至亚洲、东非并进入美洲。未发现单一地点存在不同基因型大量共同传播的证据，这表明除了地理接近性之外，某些因素可能会限制新的DENV-3变体的持续扩散和重新引入。进化速率的估算结果显示，主要DENV-3基因型之间没有显著差异。在长期地方性传播地区（即印度尼西亚和泰国），DENV-3的平均进化速率与在登革热传播较晚的美洲所观察到的速率相似。我们估计DENV-3病毒起源于1890年左右，当前主要DENV-3基因型的多样性出现在20世纪60年代中期至70年代中期，这与人口增长、城市化、大规模人口流动以及亚洲首次出现DENV-3出血热病例的描述相吻合。
