Bamunuarachchi Gayan, Najera Fernando, Aziati Ishmael D, Palmer Jamie L, Biro Elizabeth G, Wang Dave, Deem Sharon L, Boon Adrianus C M, Adalsteinsson Solny A
Department of Medicine, at Washington University School of Medicine in St. Louis. USA.
Institute for Conservation Medicine, Saint Louis Zoo. USA.
bioRxiv. 2024 Jun 4:2024.06.04.597417. doi: 10.1101/2024.06.04.597417.
Bourbon virus (BRBV) is an emerging pathogen that can cause severe and fatal disease in humans. BRBV is vectored by (lone star ticks), which are widely distributed across the central, southern, and eastern United States. Wildlife species are potentially important for the maintenance and transmission of BRBV, but little is known about which species are involved, and what other factors play a role in the exposure to BRBV. To assess the exposure risk to BRBV among wildlife in the St. Louis area, we collected sera from 98 individuals, representing 6 different mammalian species from two locations in St. Louis County: Tyson Research Center (TRC) and WildCare Park (WCP) from fall 2021 to spring 2023. The sera were used in a BRBV neutralization assay to detect neutralizing antibodies and RT-qPCR for viral RNA analysis. We also sampled and compared the abundance of ticks at the two locations and modeled which factors influenced BRBV seropositivity across species. In TRC, we observed a high rate of seropositivity in raccoons ( 23/25), and white-tailed deer ( 18/27), but a low rate in opossums ( 1/18). Neutralizing antibodies were also detected in sampled TRC bobcats ( 4/4), coyotes ( 3/3), and a red fox ( 1/1). The virological analysis identified BRBV RNA in one of the coyote serum samples. In contrast to TRC, all sera screened from WCP were negative for BRBV-specific neutralizing antibodies, and significantly fewer ticks were collected at WCP (31) compared to TRC (2,316). Collectively, these findings suggest that BRBV circulates in multiple wildlife species in the St. Louis area and that tick density and host community composition may be important factors in BRBV ecology.
波旁病毒（BRBV）是一种新出现的病原体，可导致人类严重和致命疾病。BRBV由孤星蜱传播，孤星蜱广泛分布于美国中部、南部和东部。野生动物物种对于BRBV的维持和传播可能具有重要意义，但对于哪些物种参与其中以及其他哪些因素在BRBV暴露中起作用知之甚少。为了评估圣路易斯地区野生动物接触BRBV的风险，我们从98只个体中采集了血清，这些个体代表了来自圣路易斯县两个地点的6种不同哺乳动物物种：泰森研究中心（TRC）和野生护理公园（WCP），时间从2021年秋季至2023年春季。这些血清用于BRBV中和试验以检测中和抗体，并用于逆转录定量聚合酶链反应（RT-qPCR）进行病毒RNA分析。我们还在这两个地点对蜱的丰度进行了采样和比较，并建立模型以确定哪些因素影响不同物种的BRBV血清阳性率。在TRC，我们观察到浣熊（23/25）和白尾鹿（18/27）的血清阳性率较高，但负鼠（1/18）的血清阳性率较低。在采样的TRC山猫（4/4）、郊狼（3/3）和一只赤狐（1/1）中也检测到了中和抗体。病毒学分析在一份郊狼血清样本中鉴定出了BRBV RNA。与TRC相反，从WCP筛选的所有血清的BRBV特异性中和抗体均为阴性，并且与TRC（2316只）相比，在WCP采集的蜱明显更少（31只）。总体而言，这些发现表明BRBV在圣路易斯地区的多种野生动物物种中传播，蜱的密度和宿主群落组成可能是BRBV生态学中的重要因素。
