Emerg Infect Dis. 2018 Dec;24(12):2150-7. doi: 10.3201/eid2412.180372.
We summarize and analyze historical and current data regarding the reemergence of St. Louis encephalitis virus (SLEV; genus Flavivirus) in the Americas. Historically, SLEV caused encephalitis outbreaks in the United States; however, it was not considered a public health concern in the rest of the Americas. After the introduction of West Nile virus in 1999, activity of SLEV decreased considerably in the United States. During 2014-2015, SLEV caused a human outbreak in Arizona and caused isolated human cases in California in 2016 and 2017. Phylogenetic analyses indicate that the emerging SLEV in the western United States is related to the epidemic strains isolated during a human encephalitis outbreak in Córdoba, Argentina, in 2005. Ecoepidemiologic studies suggest that the emergence of SLEV in Argentina was caused by the introduction of a more pathogenic strain and increasing populations of the eared dove (amplifying host).
我们总结和分析了有关圣路易斯脑炎病毒（SLEV；黄病毒属）在美洲重新出现的历史和当前数据。历史上，SLEV 在美国引起了脑炎爆发；然而，在美洲其他地区，它并不被视为公共卫生关注的问题。自 1999 年西尼罗河病毒引入以来，SLEV 在 美国的活动大大减少。2014-2015 年，SLEV 在亚利桑那州引起了人类爆发，并在 2016 年和 2017 年在加利福尼亚州引起了孤立的人类病例。系统发育分析表明，美国西部新出现的 SLEV 与 2005 年在阿根廷科尔多瓦发生的人类脑炎爆发期间分离出的流行株有关。生态流行病学研究表明，阿根廷 SLEV 的出现是由更具致病性的菌株的引入和扇尾鸽（扩增宿主）种群的增加引起的。
