Florida Medical Entomology Laboratory, University of Florida IFAS, 200 9th Street SE, Vero Beach, FL 32962, USA.
Center for Global Health Infectious Disease Research, University of South Florida, 3720 Spectrum Blvd., Suite 304, Tampa, FL 33612, USA.
J Med Entomol. 2022 Jan 12;59(1):41-48. doi: 10.1093/jme/tjab076.
Eastern equine encephalitis virus (EEEV; family Togaviridae, genus Alphavirus) is a mosquito-borne pathogen found in eastern North America that causes severe disease in humans and horses. The mosquito Culiseta melanura (Coquillett) (Diptera: Culicidae) is the primary enzootic vector of EEEV throughout eastern North America while several mosquito species belonging to diverse genera serve as bridge vectors. The ecology of EEEV differs between northern and southern foci, with respect to phenology of outbreaks, important vertebrate hosts, and bridge vector species. Active transmission is limited to roughly half of the year in northern foci (New York, New Hampshire, Massachusetts, Connecticut), while year-round transmission occurs in the southeastern region (particularly Florida). Multiple phylogenetic analyses indicate that EEEV strains circulating in northern foci are likely transported from southern foci by migrating birds. Bird species that overwinter or migrate through Florida, are bitten by Cs. melanura in late spring, and arrive at northern breeding grounds in May are the most likely candidates to disperse EEEV northward. Available data indicate that common yellowthroat and green heron satisfy these criteria and could serve as virus dispersers. Understanding the factors that drive the phenology of Cs. melanura reproduction in the south and the timing of avian migration from southern foci could provide insight into how confluence of these biological phenomena shapes outbreaks of EEE throughout its range. This information could be used to develop models predicting the likelihood of outbreaks in a given year, allowing vector control districts to more efficiently marshal resources necessary to protect their stakeholders.
东部马脑炎病毒（EEEV；披膜病毒科，甲病毒属）是一种在北美东部发现的由蚊子传播的病原体，可导致人类和马严重患病。库蚊属（Culex）的库蚊（双翅目：蚊科）是 EEEV 在整个北美东部的主要地方性传播媒介，而属于不同属的几种蚊子则作为桥梁媒介。EEEV 的生态学在北部和南部焦点之间存在差异，涉及暴发的物候学、重要的脊椎动物宿主和桥梁媒介物种。在北部焦点（纽约、新罕布什尔州、马萨诸塞州、康涅狄格州），活跃传播仅限于大约半年的时间，而在东南部地区（特别是佛罗里达州）则全年传播。多项系统发育分析表明，在北部焦点循环的 EEEV 株可能是由候鸟从南部焦点携带而来的。那些在佛罗里达州越冬或迁徙的鸟类，在春末被库蚊叮咬，并于 5 月到达北部繁殖地，最有可能将 EEEV 向北传播。现有数据表明，黄喉鹀和绿鹭符合这些标准，可能成为病毒的传播者。了解导致库蚊在南部繁殖物候学的因素以及候鸟从南部焦点迁徙的时间，可能有助于了解这些生物现象的融合如何塑造 EEE 在其范围内的暴发。这些信息可用于开发预测特定年份暴发可能性的模型，使媒介控制区能够更有效地调动资源，以保护其利益相关者。
