Phylodynamics of Yellow Fever Virus in the Americas: new insights into the origin of the 2017 Brazilian outbreak
Phylodynamics of Yellow Fever Virus in the Americas: new insights into the origin of the 2017 Brazilian outbreak
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DOI：
10.1038/s41598-017-07873-7
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发表时间：
2017-08-07
影响因子：
4.6
通讯作者：
Bello, Gonzalo
中科院分区：
文献类型：
--
作者：
Mir, Daiana;Delatorre, Edson;Bello, Gonzalo
在美洲传播的黄热病病毒 (YFV) 毒株属于两种不同的基因型（I 和 II），这两种基因型已多样化为几种同时存在的地方性动物谱系。自 1999 年以来，YFV 基因型 I 已在流行地区以外传播，最近（2017 年）在非流行的巴西东南部各州重新出现，引发了该国记录的最大规模的丛林黄热病流行之一。为了更好地理解这一现象，我们使用 60 年来从 9 个国家采样的序列（包括 2017 年巴西爆发的毒株）重建了美国 YFV 基因型的系统动力学。我们的分析表明，直到 20 世纪 90 年代初，YFV 基因型 I 和 II 遵循大致相似的进化和人口动态，当时基因型 I 的多样化过程发生了与新谱系（此处称为现代谱系）的出现和传播相关的巨大变化。特立尼达和多巴哥是 YFV 现代谱系最有可能的来源，该谱系在 20 世纪 80 年代末左右传播到巴西和委内瑞拉，取代了之前传播的所有谱系。现代谱系导致了自 2000 年以来在南美非地方性地区发现的所有主要 YFV 爆发，包括 2017 年巴西的爆发，其传播与几种氨基酸取代的积累有关，特别是在非结构病毒蛋白中。
Yellow fever virus (YFV) strains circulating in the Americas belong to two distinct genotypes (I and II) that have diversified into several concurrent enzootic lineages. Since 1999, YFV genotype I has spread outside endemic regions and its recent (2017) reemergence in non-endemic Southeastern Brazilian states fuels one of the largest epizootic of jungle Yellow Fever registered in the country. To better understand this phenomenon, we reconstructed the phylodynamics of YFV American genotypes using sequences from nine countries sampled along 60 years, including strains from Brazilian 2017 outbreak. Our analyses reveals that YFV genotypes I and II follow roughly similar evolutionary and demographic dynamics until the early 1990s, when a dramatic change in the diversification process of the genotype I occurred associated with the emergence and dissemination of a new lineage (here called modern). Trinidad and Tobago was the most likely source of the YFV modern-lineage that spread to Brazil and Venezuela around the late 1980s, where it replaced all lineages previously circulating. The modern-lineage caused all major YFV outbreaks detected in non-endemic South American regions since 2000, including the 2017 Brazilian outbreak, and its dissemination was coupled to the accumulation of several amino acid substitutions particularly within non-structural viral proteins.