Background

Zika virus (ZIKV) was initially responsible for a limited number of punctual epidemics throughout Africa and Asia. Recently, large epidemics occurred in French Polynesia, Brazil and Pan-America. These outbreaks were associated with severe outcomes such as Guillain-Barré Syndrome and microcephaly of in-utero infected newborns. Previous studies demonstrated that ZIKV was introduced in Brazil from French Polynesia but failed to identify a founding event.

Method

All publicly available ZIKV full-genome sequences (n = 182) were phylogenetically analyzed, using Bayesian method, to estimate the introduction date of ZIKV into Brazil.

Results

Introduction date into Brazil was estimated between 8th of July 2013 and 4th of November 2013, encompassing the Beach Soccer World Cup held in French Polynesia, in September 2013, which gathered Brazilian athletes and supporters. We also observed that ZIKV sequences from travelers infected in South-East Asia or in Pacific islands were closely related to viruses identified prior to the French Polynesian epidemic, underlining an endemic circulation of ZIKV in those countries since 2007, at least.

Conclusion

This work provides a narrower estimation of ZIKV introduction into Brazil and illustrates the need for a better exploration of ZIKV circulation and endemicity in South-East Asia, while epidemiological and prevention efforts have been mainly focused on the Pan-American epidemic.

中文翻译：

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2013 年在塔希提岛举行的沙滩足球世界杯的参与者​​将寨卡病毒引入巴西：系统地理学分析

背景

寨卡病毒 (ZIKV) 最初是造成整个非洲和亚洲数量有限的准时流行病的原因。近期，法属波利尼西亚、巴西和泛美出现大流行。这些爆发与严重后果有关，例如吉兰-巴利综合征和宫内受感染新生儿的小头畸形。以前的研究表明，ZIKV 是从法属波利尼西亚引入巴西的，但未能确定创始事件。

方法

使用贝叶斯方法对所有公开可用的 ZIKV 全基因组序列 (n = 182) 进行了系统发育分析，以估计 ZIKV 传入巴西的日期。

结果

引入巴西的日期估计在 2013 年 7 月 8 日至 2013 年 11 月 4 日之间，包括 2013 年 9 月在法属波利尼西亚举行的沙滩足球世界杯，巴西运动员和支持者云集。我们还观察到，在东南亚或太平洋岛屿上感染的旅行者的 ZIKV 序列与法属波利尼西亚流行病之前发现的病毒密切相关，这表明至少自 2007 年以来这些国家的 ZIKV 呈地方性流行。

结论

这项工作对 ZIKV 传入巴西进行了更窄的估计，并说明需要更好地探索 ZIKV 在东南亚的传播和流行，而流行病学和预防工作主要集中在泛美流行病上。