Vector-Host Interactions Governing Epidemiology of West Nile Virus in Southern California
Vector-Host Interactions Governing Epidemiology of West Nile Virus in Southern California
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DOI：
10.4269/ajtmh.2010.10-0392
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发表时间：
2010-12-01
影响因子：
3.3
通讯作者：
Andreadis, Theodore G.
中科院分区：
文献类型：
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作者：
Molaei, Goudarz;Cummings, Robert F.;Andreadis, Theodore G.
南加州仍然是西尼罗河病毒（WNV）活动的一个重要焦点，2003年该病毒入侵后发病率持续上升，随后在2004年扩大到流行水平。媒介-宿主-病原体相互作用的生态流行病学研究对于更好地了解西尼罗河病毒和其他新出现的蚊媒虫媒病毒的传播动态至关重要。我们调查了载体-宿主相互作用和宿主喂养模式的531吸血蚊子在四个主管蚊子载体，通过使用聚合酶链反应（PCR）的方法，针对线粒体DNA，以确定脊椎动物宿主的吸血蚊子。通过细胞培养、实时逆转录酶-PCR和免疫测定的诊断测试被用来检查吸血蚊子、蚊子池、死鸟和哺乳动物中的西尼罗河病毒感染。通过阻断酶联免疫吸附试验估计野生鸟类中西尼罗河病毒抗体的流行。对饱血致倦库蚊的分析表明，这种蚊子从鸟类和哺乳动物宿主（包括人类）获得了88.4%的血液。同样，跗库蚊82%以鸟类为食，18%以哺乳动物为食。红胸库蚊取食鸟类（59%）和哺乳动物（41%）。相反，斑体库蚊从禽类宿主获得所有血粉。家雀和其他几种大部分是雀形目的鸟类是吸血蚊子的主要宿主。研究期间，在蚊池、野鸟、死鸟和哺乳动物中检测到了西尼罗河病毒感染的证据，包括人类死亡。我们的研究结果强调的重要作用，家雀和其他几个雀形目鸟类在维护和放大西尼罗河病毒在南加州，与Cx。致倦犬既是主要的地方性流行病，也是负责西尼罗河病毒向人类传播的“桥梁媒介”。其他蚊子种类，如A。tarsalis和Cx.气门是重要的，但分布不太广泛，也有助于西尼罗河病毒在南加州的时空传播。
Southern California remains an important focus of West Nile virus (WNV) activity, with persistently elevated incidence after invasion by the virus in 2003 and subsequent amplification to epidemic levels in 2004. Eco-epidemiological studies of vectors-hosts-pathogen interactions are of paramount importance for better understanding of the transmission dynamics of WNV and other emerging mosquito-borne arboviruses. We investigated vector-host interactions and host-feeding patterns of 531 blood-engorged mosquitoes in four competent mosquito vectors by using a polymerase chain reaction (PCR) method targeting mitochondrial DNA to identify vertebrate hosts of blood-fed mosquitoes. Diagnostic testing by cell culture, real-time reverse transcriptase-PCR, and immunoassays were used to examine WNV infection in blood-fed mosquitoes, mosquito pools, dead birds, and mammals. Prevalence of WNV antibodies among wild birds was estimated by using a blocking enzyme-linked immunosorbent assay. Analyses of engorged Culex quinquefasciatus revealed that this mosquito species acquired 88.4% of the blood meals from avian and 11.6% from mammalian hosts, including humans. Similarly, Culex tarsalis fed 82% on birds and 18% on mammals. Culex erythrothorax fed on both birds (59%) and mammals (41%). In contrast, Culex stigmatosoma acquired all blood meals from avian hosts. House finches and a few other mostly passeriform birds served as the main hosts for the blood-seeking mosquitoes. Evidence of WNV infection was detected in mosquito pools, wild birds, dead birds, and mammals, including human fatalities during the study period. Our results emphasize the important role of house finches and several other passeriform birds in the maintenance and amplification of WNV in southern California, with Cx. quinquefasciatus acting as both the principal enzootic and "bridge vector" responsible for the spillover of WNV to humans. Other mosquito species, such as a. tarsalis and Cx. stigmatosoma are important but less widely distributed, and also contribute to spatial and temporal transmission of WNV in southern California.