1Department of Zoology, University of Oxford, Oxford, United Kingdom.
2Department of Research in Virology and Biotechnology, Gorgas Memorial Institute of Health Studies, Panama City, Panama.
Am J Trop Med Hyg. 2020 Dec;103(6):2429-2437. doi: 10.4269/ajtmh.20-0408. Epub 2020 Oct 22.
Madariaga virus (MADV) has recently been associated with severe human disease in Panama, where the closely related Venezuelan equine encephalitis virus (VEEV) also circulates. In June 2017, a fatal MADV infection was confirmed in a community of Darien Province. We conducted a cross-sectional outbreak investigation with human and mosquito collections in July 2017, where sera were tested for alphavirus antibodies and viral RNA. In addition, by applying a catalytic, force-of-infection (FOI) statistical model to two serosurveys from Darien Province in 2012 and 2017, we investigated whether endemic or epidemic alphavirus transmission occurred historically. In 2017, MADV and VEEV IgM seroprevalences were 1.6% and 4.4%, respectively; IgG antibody prevalences were MADV: 13.2%, VEEV: 16.8%, Una virus (UNAV): 16.0%, and Mayaro virus: 1.1%. Active viral circulation was not detected. Evidence of MADV and UNAV infection was found near households, raising questions about its vectors and enzootic transmission cycles. Insomnia was associated with MADV and VEEV infections, depression symptoms were associated with MADV, and dizziness with VEEV and UNAV. Force-of-infection analyses suggest endemic alphavirus transmission historically, with recent increased human exposure to MADV and VEEV in Aruza and Mercadeo, respectively. The lack of additional neurological cases suggests that severe MADV and VEEV infections occur only rarely. Our results indicate that over the past five decades, alphavirus infections have occurred at low levels in eastern Panama, but that MADV and VEEV infections have recently increased-potentially during the past decade. Endemic infections and outbreaks of MADV and VEEV appear to differ spatially in some locations of eastern Panama.
马德拉病毒（MADV）最近与巴拿马的严重人类疾病有关，在那里，密切相关的委内瑞拉马脑炎病毒（VEEV）也在传播。2017 年 6 月，在达连省的一个社区确诊了一例致命的 MADV 感染病例。我们于 2017 年 7 月进行了一项横断面暴发调查，包括人类和蚊子的采集，检测血清中的甲病毒抗体和病毒 RNA。此外，通过对 2012 年和 2017 年达连省的两项血清学调查应用催化、感染力（FOI）统计模型，我们研究了历史上是否发生了地方性或流行性甲病毒传播。2017 年，MADV 和 VEEV IgM 血清阳性率分别为 1.6%和 4.4%；MADV IgG 抗体阳性率为 13.2%，VEEV 为 16.8%，Una 病毒（UNAV）为 16.0%，Mayaro 病毒为 1.1%。未检测到活病毒循环。在家户附近发现了 MADV 和 UNAV 感染的证据，这引发了关于其传播媒介和地方性传播周期的问题。失眠与 MADV 和 VEEV 感染有关，抑郁症状与 MADV 有关，头晕与 VEEV 和 UNAV 有关。感染力分析表明，历史上存在地方性甲病毒传播，最近在 Aruza 和 Mercadeo 地区，人类暴露于 MADV 和 VEEV 的风险增加。没有其他神经病例表明，严重的 MADV 和 VEEV 感染很少发生。我们的结果表明，在过去的五十年中，在巴拿马东部地区，甲病毒感染一直处于低水平，但最近 MADV 和 VEEV 的感染有所增加——可能在过去十年中。MADV 和 VEEV 的地方性感染和暴发在巴拿马东部的一些地区似乎在空间上有所不同。
