Reisen W K, Lothrop H D, Presser S B, Milby M M, Hardy J L, Wargo M J, Emmons R W
Division of Epidemiology and Public Health Biology, School of Public Health, University of California, Berkeley 94720, USA.
J Med Entomol. 1995 May;32(3):255-66. doi: 10.1093/jmedent/32.3.255.
Consistent temporal and spatial patterns in the activity of Culex tarsalis Coquillett and western equine encephalomyelitis (WEE) and St. Louis encephalitis (SLE) viruses were delineated that were useful in developing a stratified surveillance program. Vernal increases in Cx. tarsalis abundance typically were associated with flooding of saline marshes along the north shore of the Salton Sea and were followed 6-8 wk later by the onset of WEE and SLE virus activity. Viruses then spread to managed marsh (duck club) and agricultural habitats in the Whitewater Channel flood plain and, depending upon the intensity of amplification, to agricultural and residential areas in the more elevated northwestern portion of the valley. Mean annual Cx. tarsalis abundance was correlated inversely with elevation and distance from the Salton Sea. Abundance was greatest at managed marsh habitats. Although spatially correlated with vector abundance among sites, virus transmission rates to sentinel chickens were asynchronous temporally with vector abundance. Seroconversion rates were related to flock location but not flock size (10 versus 20 chickens). Human cases were not detected during the study period, despite elevated transmission rates of both WEE and SLE viruses to sentinel chickens positioned in peridomestic habitats.
尖音库蚊（Culex tarsalis Coquillett）与西部马脑炎（WEE）病毒和圣路易斯脑炎（SLE）病毒活动中一致的时空模式被描绘出来，这对制定分层监测计划很有用。尖音库蚊数量在春季的增加通常与索尔顿海北岸盐沼的洪水有关，6 - 8周后随之而来的是WEE和SLE病毒活动的开始。然后病毒传播到白水河道洪泛平原的人工管理沼泽（鸭俱乐部）和农业栖息地，并根据扩增强度传播到山谷西北部地势较高处的农业和居民区。尖音库蚊的年平均数量与海拔高度以及与索尔顿海的距离呈负相关。在人工管理的沼泽栖息地数量最多。尽管在不同地点之间病毒传播率与病媒数量在空间上相关，但向哨兵鸡的病毒传播率在时间上与病媒数量不同步。血清转化率与鸡群位置有关，但与鸡群大小无关（10只鸡与20只鸡）。尽管在研究期间WEE和SLE病毒向位于住宅周边栖息地的哨兵鸡的传播率有所升高，但未检测到人类病例。
