On the Edge: Dengue and Climate

边缘：登革热和气候

• 批准号: 8238915
• 负责人: Kacey C Ernst
• 金额: $ 59.23万
• 依托单位: UNIVERSITY OF ARIZONA
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-09-01 至 2016-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8238915
• 关键词: Adult; Aedes; Affect; Age; Area; Arizona; Automobile Driving; Behavior; Blood; Cities; Climate; Collection; Communicable Diseases; Communities; Country; Coupled; Culicidae; Data; Dengue; Dengue Virus; Disease; Disease Outbreaks; Disease Vectors; Dryness; Environmental Risk Factor; Fertility; Future; Genes; Geographic Locations; Goals; Heating; Household; Human; Humidity; Infection; Length; Longevity; Maps; Measures; Mediating; Mexican; Mexico; Modeling; Molecular; Outcome; Parasites; Play; Population; Population Density; Recording of previous events; Relative (related person); Reporting; Rest; Risk; Role; Sampling; Seasons; Side; Site; Stretching; Structure; Surveys; Temperature; Testing; Texas; Translating; United States; Virus; Water; Yellow Fever; aged; chikungunya; climate change; density; design; disease transmission; disorder risk; experience; feeding; information gathering; innovation; meetings; parity; residence; social; tool; transmission process; trend; urban area; vector

DESCRIPTION (provided by applicant): Aedes aegypti mosquitoes are the primary vector for dengue, yellow fever and chikungunya. The vector is present in most urban communities stretching along the U.S.-Mexico border yet dengue transmission has only been noted in two U.S. border communities in Texas, notably Brownsville and Laredo, TX. While many argue that this is a result of different social factors across the border, this fails to explain the lack of transmission in some communities in northern Mexico, notably Nogales, Sonora. Nogales is a large urban area on the Mexican side of the border with large vector populations and a constant influx of people from dengue endemic areas yet no local cases have been recorded. Vector presence alone is not sufficient to cause disease transmission; vectors must also survive long enough to blood feed and become infected, have the parasite develop and feed again, transmitting the virus. Climatic influences on the lifespan and behavior of Ae. aegypti may also influence the risk of dengue transmission in this region which lies at the boundary of both virus and vector. Geographic areas such as this, at the edge of the range of disease and vector, are at greatest risk of emergence and reemergence of infectious diseases. We will assess the relative age structure of Ae. aegypti populations in nine cities with varying climates in the southern United States and Sonora, MX by trapping and molecularly determining the ages of adult Ae. aegypti during four mosquito seasons. We expect that cities with extremely dry and hot conditions will have younger Ae. aegypti populations. Cities with reported dengue transmission we expect to have Ae. aegypti that are on average younger when taking their first blood meal than cities without transmission. To determine how the age of Ae. aegypti population vary over a finer spatial scale, we will sample adults in 150 households in Hermosillo, Mexico; a city with a history of dengue outbreaks. Additionally, we will survey the households for potential social and environmental factors that mediate the relationship between climate and longevity. We expect to find significant variability across households. Residences with older mosquitoes will have more vegetation, fewer barriers to mosquito access and indoor resting sites, no competing vector species and no control measures. From the information gathered in the first two objectives, we will construct a model to predict the likelihood of the expansion of Ae. aegypti populations that survive long enough to transmit dengue and thus changes in risk of dengue transmission. We expect that models of risk of dengue under climate change scenarios will decrease in areas that surpass a heat and dryness threshold and will increase in populations with increasing moisture. PUBLIC HEALTH RELEVANCE: This study will advance understanding related to the impact of climate change on the possible emergence of dengue in the southern United States and northern Mexico. A key outcome will be a broader understanding of how climatic changes would impact the longevity of the Aedes aegypti mosquito, a critical component of disease transmission. Risk maps will be generated that depict changes in density of vector's capable of transmission and length of mosquito season.

描述（由申请人提供）：埃及伊蚊是登革热、黄热病和基孔肯雅热的主要传播媒介。该媒介存在于美国-墨西哥边境沿线的大多数城市社区，但仅在德克萨斯州的两个美国边境社区发现登革热传播，特别是德克萨斯州的布朗斯维尔和拉雷多。尽管许多人认为这是跨境不同社会因素的结果，但这无法解释墨西哥北部一些社区（尤其是索诺拉州诺加莱斯）缺乏传播的原因。诺加利斯是墨西哥边境一侧的一个大城市地区，媒介人口众多，来自登革热流行区的人员不断涌入，但尚未记录当地病例。仅存在媒介并不足以引起疾病传播；载体还必须存活足够长的时间才能吸血并被感染，让寄生虫发育并再次吸食，从而传播病毒。气候对伊蚊的寿命和行为的影响。埃及伊蚊还可能影响该地区登革热传播的风险，该地区位于病毒和媒介的边界。像这样的地理区域位于疾病和媒介范围的边缘，传染病出现和再次出现的风险最大。我们将评估 Ae 的相对年龄结构。通过捕获和分子测定成年伊蚊的年龄，研究了美国南部和墨西哥索诺拉州九个气候不同的城市的埃及伊蚊种群。埃及伊蚊在四个蚊子季节。我们预计，极端干燥和炎热的城市将出现较年轻的Ae。埃及伊蚊种群。我们预计在有登革热传播报告的城市中会出现白伊菌。与没有传播的城市相比，埃及伊蚊在第一次吸血时平均年龄更年轻。如何确定Ae的年龄。埃及伊蚊种群在更精细的空间尺度上变化，我们将对墨西哥埃莫西约 150 个家庭的成年伊蚊进行抽样；一座有登革热疫情历史的城市。此外，我们还将调查家庭，了解调节气候与寿命之间关系的潜在社会和环境因素。我们预计不同家庭之间存在显着差异。有老蚊子的住宅将有更多的植被，蚊子进入和室内休息场所的障碍更少，没有竞争性媒介物种，也没有控制措施。根据前两个目标收集的信息，我们将构建一个模型来预测 Ae 扩张的可能性。埃及伊蚊种群存活时间足以传播登革热，从而改变登革热传播的风险。我们预计，气候变化情景下的登革热风险模型将在超过炎热和干燥阈值的地区减少，并随着湿度的增加而增加。 公共卫生相关性：这项研究将增进人们对气候变化对美国南部和墨西哥北部可能出现登革热的影响的了解。一个关键成果将是更广泛地了解气候变化将如何影响埃及伊蚊的寿命，埃及伊蚊是疾病传播的关键组成部分。将生成风险地图，描述能够传播的媒介密度的变化以及蚊子季节的长度。