On the origin and timing of Zika virus introduction in Brazil
On the origin and timing of Zika virus introduction in Brazil
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DOI：
10.1017/s0950268817001200
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发表时间：
2017-08-01
影响因子：
4.2
通讯作者：
Wilder-Smith, A.
中科院分区：
文献类型：
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作者：
Massad, E.;Nascimento Burattini, M.;Wilder-Smith, A.
寨卡病毒（ZIKV）在巴西传入的时间和起源一直是争议的主题。最初，人们认为该病毒是在2014年6月至7月的国际足联世界杯期间引入的。当时，人们推测寨卡病毒可能是由2014年8月在法属波利尼西亚（FP）参加巴西里约热内卢独木舟比赛的运动员引入的。我们试图应用数学模型来确定巴西寨卡病毒最可能传入的时间窗口。鉴于寨卡病毒在巴西传播的时间和起源可能是一个政治敏感问题，它的确定（或提供一个合理的假设）可能有助于防止不应有的指责。我们用一个简单的数学模型来估计感染力和相应的个体感染寨卡病毒的概率。考虑到2013年10月至2014年3月期间从FP到巴西的航空旅行量，我们估计了在此期间抵达巴西机场的受感染旅客的预期人数。在2013年12月至2014年2月期间，51人从FP机场前往巴西11个城市。根据计算的寨卡病毒感染力（单位时间内人均新增感染率）和感染风险（至少1例新增感染的概率），我们估计在7个被评估城市中有18人（95% CI 12-22）被感染。当假设七个被评估城市的寨卡病毒基本繁殖数大于1时，寨卡病毒可能已经传入任何一个城市。根据FP的感染强度、巴西选定城市中寨卡病毒的基本繁殖数量以及估计的旅行量，我们得出结论，寨卡病毒最有可能是在2013年10月至2014年3月期间由来自FP的受感染旅行者引入并在巴西建立的，这是在上述两项体育赛事之前。
The timing and origin of Zika virus (ZIKV) introduction in Brazil has been the subject of controversy. Initially, it was assumed that the virus was introduced during the FIFA World Cup in June-July 2014. Then, it was speculated that ZIKV may have been introduced by athletes from French Polynesia (FP) who competed in a canoe race in Rio de Janeiro in August 2014. We attempted to apply mathematical models to determine the most likely time window of ZIKV introduction in Brazil. Given that the timing and origin of ZIKV introduction in Brazil may be a politically sensitive issue, its determination (or the provision of a plausible hypothesis) may help to prevent undeserved blame. We used a simple mathematical model to estimate the force of infection and the corresponding individual probability of being infected with ZIKV in FP. Taking into account the air travel volume from FP to Brazil between October 2013 and March 2014, we estimated the expected number of infected travellers arriving at Brazilian airports during that period. During the period between December 2013 and February 2014, 51 individuals travelled from FP airports to 11 Brazilian cities. Basing on the calculated force of ZIKV infection (the per capita rate of new infections per time unit) and risk of infection (probability of at least one new infection), we estimated that 18 (95% CI 12-22) individuals who arrived in seven of the evaluated cities were infected. When basic ZIKV reproduction numbers greater than one were assumed in the seven evaluated cities, ZIKV could have been introduced in any one of the cities. Based on the force of infection in FP, basic reproduction ZIKV number in selected Brazilian cities, and estimated travel volume, we concluded that ZIKV was most likely introduced and established in Brazil by infected travellers arriving from FP in the period between October 2013 and March 2014, which was prior to the two aforementioned sporting events.