Basque Center for Applied Mathematics (BCAM), Bilbao, Spain.
Department of Public Health Sciences, University of California Davis, Davis, California, United States of America.
PLoS One. 2023 Sep 13;18(9):e0290387. doi: 10.1371/journal.pone.0290387. eCollection 2023.
To estimate the instantaneous reproduction number Rt and the epidemic growth rates for the 2022 monkeypox outbreaks in the European region.
We gathered daily laboratory-confirmed monkeypox cases in the most affected European countries from the beginning of the outbreak to September 23, 2022. A data-driven estimation of the instantaneous reproduction number is obtained using a novel filtering type Bayesian inference. A phenomenological growth model coupled with a Bayesian sequential approach to update forecasts over time is used to obtain time-dependent growth rates in several countries.
The instantaneous reproduction number Rt for the laboratory-confirmed monkeypox cases in Spain, France, Germany, the UK, the Netherlands, Portugal, and Italy. At the early phase of the outbreak, our estimation for Rt, which can be used as a proxy for the basic reproduction number R0, was 2.06 (95% CI 1.63 - 2.54) for Spain, 2.62 (95% CI 2.23 - 3.17) for France, 2.81 (95% CI 2.51 - 3.09) for Germany, 1.82 (95% CI 1.52 - 2.18) for the UK, 2.84 (95% CI 2.07 - 3.91) for the Netherlands, 1.13 (95% CI 0.99 - 1.32) for Portugal, 3.06 (95% CI 2.48 - 3.62) for Italy. Cumulative cases for these countries present subexponential rather than exponential growth dynamics.
Our findings suggest that the current monkeypox outbreaks present limited transmission chains of human-to-human secondary infection so the possibility of a huge pandemic is very low. Confirmed monkeypox cases are decreasing significantly in the European region, the decline might be attributed to public health interventions and behavioral changes in the population due to increased risk perception. Nevertheless, further strategies toward elimination are essential to avoid the subsequent evolution of the monkeypox virus that can result in new outbreaks.
估计 2022 年欧洲地区猴痘疫情的即时繁殖数 Rt 和疫情增长率。
我们从疫情开始到 2022 年 9 月 23 日，收集了受影响最严重的欧洲国家的每日实验室确诊猴痘病例。使用新型滤波型贝叶斯推断方法获得即时繁殖数的估计值。使用耦合现象学增长模型和贝叶斯序贯方法随时间更新预测的方法，获得了几个国家的时变增长率。
西班牙、法国、德国、英国、荷兰、葡萄牙和意大利实验室确诊猴痘病例的即时繁殖数 Rt。在疫情早期，我们对 Rt 的估计值（可作为基本繁殖数 R0 的代理）为西班牙 2.06（95%CI 1.63-2.54），法国 2.62（95%CI 2.23-3.17），德国 2.81（95%CI 2.51-3.09），英国 1.82（95%CI 1.52-2.18），荷兰 2.84（95%CI 2.07-3.91），葡萄牙 1.13（95%CI 0.99-1.32），意大利 3.06（95%CI 2.48-3.62）。这些国家的累积病例呈现出亚指数而不是指数增长动态。
我们的研究结果表明，当前的猴痘疫情传播链有限，人际二次感染的可能性较低，因此大规模流行的可能性非常低。欧洲地区的确诊猴痘病例数量显著下降，这可能归因于公共卫生干预和由于风险认知增加而导致的人群行为变化。然而，为了避免随后猴痘病毒的进化导致新的疫情爆发，还需要采取进一步的消灭策略。
