Department of Microbiology, Immunology and Pathology, College of Veterinary Medicine and Biomedical Sciences, Colorado State University, Fort Collins, CO, USA.
J Med Entomol. 2019 Feb 25;56(2):584-588. doi: 10.1093/jme/tjy214.
Western equine encephalitis (WEE) was once prevalent and routinely isolated from mosquitoes in Colorado; however, isolations of Western equine encephalitis virus (WEEV) have not been reported from mosquito pools since the early 1990s. The objective of the present study was to test pools of Culex tarsalis (Coquillett) mosquitoes sampled from Weld County, CO, in 2016 for evidence of WEEV infection. Over 7,000 mosquitoes were tested, but none were positive for WEEV RNA. These data indicate that WEEV either was not circulating enzootically in Northern Colorado, was very rare, and would require much more extensive mosquito sampling to detect, or was heterogeneously distributed spatially and temporally and happened to not be present in the area sampled during 2016. Even though the reported incidence of WEE remains null, screening for WEEV viral RNA in mosquito vectors offers forewarning toward the detection and prevention of future outbreaks.
西部马脑炎（WEE）曾经在科罗拉多州流行，并经常从蚊子中分离出来；然而，自 20 世纪 90 年代初以来，蚊子池中就没有报告过西部马脑炎病毒（WEEV）的分离。本研究的目的是检测 2016 年科罗拉多州韦尔德县采集的库蚊（Culex tarsalis）（Coquillett）蚊子的样本，以寻找 WEEV 感染的证据。共检测了超过 7000 只蚊子，但没有一只蚊子的 WEEV RNA 呈阳性。这些数据表明，WEEV 要么在科罗拉多州北部没有地方性流行，要么非常罕见，需要进行更广泛的蚊子采样才能检测到，要么在空间和时间上呈异质分布，只是碰巧不在 2016 年采样的地区。尽管报告的 WEE 发病率仍然为零，但对蚊子传播媒介中的 WEEV 病毒 RNA 进行筛查，可以提前发现并预防未来的疫情爆发。
