Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA, USA.
Department of Global Health, University of Washington, Seattle, WA, USA.
Int J Infect Dis. 2020 Oct;99:362-372. doi: 10.1016/j.ijid.2020.07.043. Epub 2020 Jul 30.
Rift Valley Fever (RVF) poses a threat to human and animal health throughout much of Africa and the Middle East and has been recognized as a global health security priority and a key preparedness target.
We combined RVF occurrence data from a systematic literature review with animal notification data from an online database. Using boosted regression trees, we made monthly environmental suitability predictions from January 1995 to December 2016 at a 5 × 5-km resolution throughout regions of Africa, Europe, and the Middle East. We calculated the average number of months per year suitable for transmission, the mean suitability for each calendar month, and the "spillover potential," a measure incorporating suitability with human and livestock populations.
Several countries where cases have not yet been reported are suitable for RVF. Areas across the region of interest are suitable for transmission at different times of the year, and some areas are suitable for multiple seasons each year. Spillover potential results show areas within countries where high populations of humans and livestock are at risk for much of the year.
The widespread environmental suitability of RVF highlights the need for increased preparedness, even in countries that have not previously experienced cases. These maps can aid in prioritizing long-term RVF preparedness activities and determining optimal times for recurring preparedness activities. Given an outbreak, our results can highlight areas often at risk for subsequent transmission that month, enabling decision-makers to target responses effectively.
裂谷热（RVF）对非洲和中东大部分地区的人类和动物健康构成威胁，已被确认为全球卫生安全重点和关键的准备目标。
我们将系统文献综述中的裂谷热发生数据与在线数据库中的动物报告数据相结合。使用增强回归树，我们在 1995 年 1 月至 2016 年 12 月期间，以 5×5km 的分辨率，对非洲、欧洲和中东地区进行了每月环境适宜性预测。我们计算了每年适合传播的平均月份数、每个日历月的平均适宜性以及“溢出潜力”，这是一个结合了适宜性与人类和牲畜数量的衡量标准。
一些尚未报告病例的国家也适合裂谷热。该地区的多个地区在一年中的不同时间适合传播，有些地区每年适合多个季节。溢出潜力的结果显示，在一些国家，大量的人类和牲畜在一年中的大部分时间都面临风险。
裂谷热广泛的环境适宜性突出表明需要加强准备工作，即使在以前没有发生过病例的国家也是如此。这些地图可以帮助确定长期裂谷热准备活动的优先事项，并确定定期准备活动的最佳时间。如果发生疫情，我们的结果可以突出当月经常面临后续传播风险的地区，使决策者能够有效地针对这些地区采取应对措施。
