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(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。这种媒介存在于沿美墨边境的大多数城市社区，但登革热的传播只在德克萨斯州的两个美国边境社区出现，特别是德克萨斯州的布朗斯维尔和拉雷多。虽然许多人认为这是边境另一边不同社会因素的结果，但这无法解释墨西哥北部一些社区缺乏传播的原因，特别是诺加莱斯和索诺拉。诺加莱斯是墨西哥边境一侧的一个大城市地区，有大量的媒介人口和来自登革热流行区的持续涌入的人，但当地尚未记录到病例。仅有病媒的存在还不足以引起疾病传播；病媒还必须存活足够长的时间以供血液喂养并被感染，使寄生虫发育并再次进食，从而传播病毒。气候对Ae.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交界处。像这样处于疾病和媒介范围边缘的地理区域，是传染病出现和重新出现的最大风险。我们将评估Ae的相对年龄结构。通过诱捕和分子测定成年埃及伊蚊的年龄，在美国南部和MX索诺拉的9个不同气候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条件的城市将会有更年轻的Ae。埃及伊蚊种群。报告了登革热传播的城市，我们预计会有Ae。埃及伊蚊在第一次进食血液时平均比没有传播的城市年轻。以确定Ae的年龄如何。埃及伊蚊的种群在更精细的空间尺度上有所不同，我们将在墨西哥埃尔莫西洛这个有登革热爆发历史的城市对150个家庭的成年人进行抽样。此外，我们将调查家庭中潜在的社会和环境因素，以调节气候和寿命之间的关系。我们预计会发现家庭之间的差异很大。有较老蚊子的住宅将有更多的植被，对蚊子进入和室内休息场所的障碍更少，没有竞争的媒介物种，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。存活足够长的埃及伊蚊种群传播登革热，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，在湿度增加的人口中增加。 公共卫生相关性：这项研究将促进对气候变化对美国南部和墨西哥北部可能出现的登革热影响的理解。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，描绘能够传播的媒介密度和蚊子季节长度的变化。