Fay R L, Cruz-Loya M, Maffei J G, Mordecai E A, Ciota A T
bioRxiv. 2025 Mar 3:2025.02.28.640855. doi: 10.1101/2025.02.28.640855.
West Nile virus (WNV), the most common mosquito-borne disease in the continental U.S., is vectored by spp. mosquitoes. Since its introduction to New York State (NYS) in 1999, WNV has become endemic. NYS temperatures have risen by 0.14°C per decade since 1900, with larger increases linked to higher WNV transmission. Using surveillance and sequencing data, we find a significant correlation between rising temperatures, increased WNV genetic diversity, and higher prevalence. Given the experimentally demonstrated role of temperature influencing WNV fitness, we hypothesized that contemporary strains should exhibit greater fitness in mosquitoes at higher temperatures compared to historic strains. To test this, we analyzed genetically distinct WNV strains from mosquitoes collected during recent warm summers (2017 and 2018) and cooler historic summers (2003 and 2004). Assessing vector competence and calculating the relative R₀ at 20°C, 24°C, and 28°C, we found that contemporary strains exhibit higher transmission potential at increased temperatures. Our results show that contemporary WNV strains possess greater phenotypic and genotypic diversity, facilitating the emergence of strains with enhanced transmission potential in a warming climate.
西尼罗河病毒（WNV）是美国大陆最常见的蚊媒疾病，由多种蚊子传播。自1999年引入纽约州（NYS）以来，WNV已成为地方病。自1900年以来，纽约州的气温每十年上升0.14°C，气温升高幅度越大，WNV传播率越高。利用监测和测序数据，我们发现气温上升、WNV遗传多样性增加和患病率升高之间存在显著相关性。鉴于实验证明温度对WNV适应性有影响，我们假设与历史毒株相比，当代毒株在较高温度下在蚊子中应表现出更强的适应性。为了验证这一点，我们分析了在近期温暖夏季（2017年和2018年）以及较凉爽的历史夏季（2003年和2004年）收集的蚊子中基因不同的WNV毒株。在20°C、24°C和28°C下评估媒介能力并计算相对R₀，我们发现当代毒株在温度升高时表现出更高的传播潜力。我们的结果表明，当代WNV毒株具有更大的表型和基因型多样性，这有助于在气候变暖的情况下出现传播潜力增强的毒株。
