Blosser Erik M, Lord Cynthia C, Stenn Tanise, Acevedo Carolina, Hassan Hassan K, Reeves Lawrence E, Unnasch Thomas R, Burkett-Cadena Nathan D
Florida Medical Entomology Laboratory, University of Florida IFAS, 200?9th St. SE, Vero Beach, FL 32962.
Department of Global Health, College of Public Health, Global Health Infectious Disease Research Program, University of South Florida, 3720 Spectrum Blvd., Suite 304, Tampa, FL 33612.
J Med Entomol. 2017 Sep 1;54(5):1365-1374. doi: 10.1093/jme/tjx140.
Field studies were carried out in four Florida counties to investigate winter and spring ecology of host use by Culiseta melanura (Coquillet), the primary vector of eastern equine encephalomyelitis virus (EEEV) in North America. Bloodmeal analysis by PCR was used to identify 233 host bloodmeals, which mainly originated from birds (78.5%) and reptiles (17.2%), primarily Anolis spp. lizards. Across counties, the percentage of bloodmeals from reptiles (7-37% depending upon county) increased with increasing day length and temperature in the spring. Multiple logistic regression revealed that differences in reptile host use across collection sites were largely explained by differences in average day length and temperature on the day of collection, and is probably owing to environment-driven behavioral patterns of ectothermic animals. Although past studies have demonstrated reptile biting by epizootic vectors of EEEV, including Culex (Melanoconion) spp., this is the first study to demonstrate widespread and common feeding upon ectothermic hosts by Cs. melanura. This work suggests that reptiles, particularly anole lizards, play a role in the ecology of EEEV in Florida either as amplifying hosts or as noncompetent hosts which dilute vector feedings thereby suppressing transmission. Detailed laboratory studies investigating impacts of environmental variables (temperature and photoperiod) on EEEV competence of anoles are needed to assess whether these animals support virus amplification.
在佛罗里达州的四个县开展了实地研究，以调查北美东部马脑脊髓炎病毒（EEEV）的主要传播媒介——黑尾库蚊（Culiseta melanura，Coquillet）在冬季和春季的宿主利用生态学。采用聚合酶链式反应（PCR）进行血餐分析，以鉴定233份宿主血餐，这些血餐主要来自鸟类（78.5%）和爬行动物（17.2%），主要是安乐蜥属蜥蜴。在各个县中，春季来自爬行动物的血餐百分比（因县而异，为7%-37%）随着日长和温度的增加而上升。多元逻辑回归分析显示，不同采集地点在利用爬行动物宿主方面的差异，很大程度上可由采集当天的平均日长和温度差异来解释，这可能是由于变温动物受环境驱动的行为模式所致。尽管过去的研究已经证明EEEV的流行传播媒介（包括库蚊属（Melanoconion）物种）会叮咬爬行动物，但这是第一项证明黑尾库蚊广泛且普遍地以变温动物宿主为食的研究。这项工作表明，爬行动物，尤其是安乐蜥，在佛罗里达州的EEEV生态学中扮演着一定角色，要么作为扩增宿主，要么作为非适宜宿主，后者通过稀释媒介的摄食从而抑制病毒传播。需要开展详细的实验室研究，调查环境变量（温度和光周期）对安乐蜥的EEEV易感性的影响，以评估这些动物是否支持病毒扩增。
