Centre for the Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, UK.
Fiji Center for Diseases Control, Suva, Fiji.
Nat Commun. 2021 Mar 15;12(1):1671. doi: 10.1038/s41467-021-21788-y.
Zika virus (ZIKV) has caused large, brief outbreaks in isolated populations, however ZIKV can also persist at low levels over multiple years. The reasons for these diverse transmission dynamics remain poorly understood. In Fiji, which has experienced multiple large single-season dengue epidemics, there was evidence of multi-year transmission of ZIKV between 2013 and 2017. To identify factors that could explain these differences in dynamics between closely related mosquito-borne flaviviruses, we jointly fit a transmission dynamic model to surveillance, serological and molecular data. We estimate that the observed dynamics of ZIKV were the result of two key factors: strong seasonal effects, which created an ecologically optimal time of year for outbreaks; and introduction of ZIKV after this optimal time, which allowed ZIKV transmission to persist over multiple seasons. The ability to jointly fit to multiple data sources could help identify a similar range of possible outbreak dynamics in other settings.
寨卡病毒（ZIKV）曾在孤立人群中引起过大规模的、短暂的暴发，但也可以在多年间以低水平持续存在。这些不同传播动态的原因仍不清楚。在斐济，曾多次经历大规模的单季登革热流行，2013 年至 2017 年间有证据表明寨卡病毒存在多年传播。为了确定这些密切相关的蚊媒黄病毒之间传播动态差异的原因，我们联合使用传播动力学模型对监测、血清学和分子数据进行拟合。我们估计，寨卡病毒的观察到的动态是两个关键因素的结果：强烈的季节性效应，创造了暴发的一年中最有利的生态时间；以及在最佳时间之后引入寨卡病毒，使得寨卡病毒的传播能够持续多个季节。联合拟合多种数据源的能力可以帮助在其他环境中识别类似的可能暴发动态范围。
