Florida Medical Entomology Laboratory, University of Florida Institute of Food and Agricultural Sciences, 200 9th St. SE, Vero Beach, FL 32962, USA.
Department of Epidemiology of Microbial Diseases, Yale School of Public Health, New Haven, CT, USA.
J Med Entomol. 2023 Nov 14;60(6):1149-1164. doi: 10.1093/jme/tjad070.
Everglades virus (EVEV) is subtype II of the Venezuelan equine encephalitis virus (VEEV) complex (Togaviridae: Alphavirus), endemic to Florida, USA. EVEV belongs to a clade that includes both enzootic and epizootic/epidemic VEEV subtypes. Like other enzootic VEEV subtypes, muroid rodents are important vertebrate hosts for EVEV and certain mosquitoes are important vectors. The hispid cotton rat Sigmodon hispidus and cotton mouse Peromyscus gossypinus are important EVEV hosts, based on natural infection (virus isolation and high seropositivity), host competence (experimental infections), and frequency of contact with the vector. The mosquito Culex (Melanoconion) cecedei is the only confirmed vector of EVEV based upon high natural infection rates, efficient vector competence, and frequent feeding upon muroid rodents. Human disease attributed to EVEV is considered rare. However, cases of meningitis and encephalitis are recorded from multiple sites, separated by 250 km or more. Phylogenetic analyses indicate that EVEV is evolving, possibly due to changes in the mammal community. Mutations in the EVEV genome are of concern, given that epidemic strains of VEEV (subtypes IAB and IC) are derived from enzootic subtype ID, the closest genetic relative of EVEV. Should epizootic mutations arise in EVEV, the abundance of Aedes taeniorhynchus and other epizootic VEEV vectors in southern Florida provides a conducive environment for widespread transmission. Other factors that will likely influence the distribution and frequency of EVEV transmission include the establishment of Culex panocossa in Florida, Everglades restoration, mammal community decline due to the Burmese python, land use alteration by humans, and climate change.
佛罗里达州的伊蚊病毒（EVEV）是委内瑞拉马脑炎病毒（VEEV）复合病毒（披膜病毒科：甲病毒属）的 II 型亚组，是地方性病毒。EVEV 属于一个支系，其中包括地方性和爆发性/流行性的 VEEV 亚型。与其他地方性 VEEV 亚型一样，沙鼠科啮齿动物是 EVEV 的重要脊椎动物宿主，某些蚊子是重要的媒介。毛尾沙鼠 Sigmodon hispidus 和棉鼠 Peromyscus gossypinus 是 EVEV 的重要宿主，这是基于自然感染（病毒分离和高血清阳性率）、宿主易感性（实验感染）以及与媒介接触的频率。Culex (Melanoconion) cecedei 蚊子是唯一被确认的 EVEV 传播媒介，这是基于高自然感染率、有效的媒介易感性以及经常以沙鼠科啮齿动物为食。归因于 EVEV 的人类疾病被认为很少见。然而，脑膜炎和脑炎的病例记录于多个地点，相隔 250 公里或更远。系统进化分析表明，EVEV 正在进化，可能是由于哺乳动物群落的变化。EVEV 基因组中的突变令人担忧，因为委内瑞拉马脑炎病毒（VEEV）的爆发性流行株（亚型 IAB 和 IC）是从地方性的 EVEV 亚型 ID 进化而来的，EVEV 是 ID 亚型最接近的遗传近亲。如果 EVEV 发生爆发性突变，佛罗里达州南部 Aedes taeniorhynchus 和其他爆发性 VEEV 媒介的丰富度为广泛传播提供了有利的环境。其他可能影响 EVEV 传播的分布和频率的因素包括 Culex panocossa 在佛罗里达州的建立、大沼泽地的恢复、由于缅甸蟒蛇而导致的哺乳动物群落的下降、人类对土地使用的改变以及气候变化。
