Caldwell Jamie M, Grenfell Bryan, Vecchi Gabriel, Rosser Joelle I
High Meadows Environmental Institute, Princeton University, Guyot Hall, Princeton, 08544, New Jersey, USA.
Department of Ecology and Evolutionary Biology, Princeton University, Guyot Hall, Princeton, 08544, New Jersey, USA.
bioRxiv. 2025 Feb 28:2025.02.25.640139. doi: 10.1101/2025.02.25.640139.
While excess rainfall is associated with mosquito-borne disease because it supports mosquito breeding, drought may also counterintuitively increase disease transmission by altering mosquito and host behavior. This phenomenon is important to understand because climate change is projected to increase both extreme rainfall and drought. In this study, we investigated the extent to which seasonally-driven mosquito and primate behavior drove the first urban yellow fever virus (YFV) epidemic in Brazil in a century, coinciding with an equally rare drought, and to assess the role of interventions in ending the outbreak. We hypothesized that drought triggered the outbreak by driving the forest mosquitoes and nonhuman primates towards the city in search of water and that the mosquitoes were biting more frequently to avoid desiccation. A dynamical YFV model supports these hypotheses, showing that increased mosquito biting can explain the second peak in transmission while primate movement determined the timing and magnitude of transmission. Further, a combination of vector control, vaccination, and conservation measures likely contributed to ending the outbreak. Together, these results suggest that drought-likely to become more frequent in this region in the coming decades-can significantly influence mosquito-borne disease transmission, and that sustained control will require multiple interventions.
虽然降雨过多与蚊媒疾病有关，因为它有利于蚊子繁殖，但干旱也可能出人意料地通过改变蚊子和宿主的行为来增加疾病传播。了解这一现象很重要，因为预计气候变化将增加极端降雨和干旱的发生频率。在本研究中，我们调查了季节性驱动的蚊子和灵长类动物行为在多大程度上导致了巴西一个世纪以来的首次城市黄热病病毒（YFV）疫情，此次疫情恰逢同样罕见的干旱，并评估了干预措施在结束疫情中的作用。我们假设干旱通过驱使森林蚊子和非人灵长类动物前往城市寻找水源引发了疫情，并且蚊子为避免脱水叮咬得更加频繁。一个动态的YFV模型支持了这些假设，表明蚊子叮咬增加可以解释传播的第二个高峰，而灵长类动物的移动决定了传播的时间和规模。此外，病媒控制、疫苗接种和保护措施的结合可能有助于结束疫情。总之，这些结果表明，干旱——在未来几十年该地区可能会更加频繁——会显著影响蚊媒疾病传播，持续的控制将需要多种干预措施。
