Komar Nicholas, Panella Nicholas A, Golnar Andrew J, Hamer Gabriel L
1 Division of Vector-Borne Diseases, Centers for Disease Control and Prevention , Fort Collins, Colorado.
2 Department of Entomology, TAMU 2475, Texas A&M University , College Station, Texas.
Vector Borne Zoonotic Dis. 2018 Sep;18(9):485-490. doi: 10.1089/vbz.2018.2285. Epub 2018 Jun 19.
Culex quinquefasciatus is the principal vector of West Nile virus (WNV) in the South Central United States, yet limited data on host utilization are available. We evaluated host utilization over a 3-month period in 2013 in a residential landscape in College Station, Texas. PCR sequencing of the mitochondrial cytochrome oxidase 1 gene permitted molecular identification of vertebrate bloodmeals to the species level. Forage ratio analysis identified bird species that were overutilized and underutilized by comparing community feeding index values to expected relative abundance values of bird species, derived from eBird data. Community feeding index values were also used in conjunction with reservoir competence data from the literature to generate reservoir capacity index values, a means of identifying relative importance of vertebrate reservoir hosts. Of 498 blood-engorged Cx. quinquefasciatus, 313 (62.9%) were identified to vertebrate species. The majority (95.5%) of bloodmeals originated from avian species with the remainder from mammals, but not humans. Northern mockingbird (Mimus polyglottos) was the principal host for mosquito feeding in June and July, but northern cardinal (Cardinalis cardinalis) became primary host in August. Forage ratio analysis revealed the overutilization of house finch (Haemorhous mexicanus), American robin (Turdus migratorius), northern mockingbird, northern cardinal, white-winged dove (Zenaida asiatica), and mourning dove (Zenaida macroura). Great-tailed grackle (Quiscalus mexicanus), blue jay (Cyanocitta cristata), and Carolina wren (Thryothorus ludovicianus) were under-utilized relative to availability. Reservoir capacity calculations suggested that northern mockingbird and northern cardinal were the principal amplifiers in the study area. These data identify the primary avian species contributing to the enzootic amplification of WNV in East-Central Texas and reveal that the heavy feeding on moderately competent hosts and no feeding on humans likely limit epidemics in this region.
致倦库蚊是美国中南部西尼罗河病毒（WNV）的主要传播媒介，但关于其宿主利用情况的数据有限。2013年，我们在得克萨斯州大学城的一个居民区景观中，对为期3个月的宿主利用情况进行了评估。通过对线粒体细胞色素氧化酶1基因进行PCR测序，可在物种水平上对脊椎动物血餐进行分子鉴定。通过比较群落摄食指数值与从eBird数据得出的鸟类预期相对丰度值，饲料比例分析确定了被过度利用和未被充分利用的鸟类物种。群落摄食指数值还与文献中的储存宿主能力数据结合使用，以生成储存宿主能力指数值，这是一种确定脊椎动物储存宿主相对重要性的方法。在498只饱血的致倦库蚊中，313只（62.9%）被鉴定出取食了脊椎动物物种。大多数血餐（95.5%）来自鸟类，其余来自哺乳动物，但没有来自人类的。北模仿鸟（Mimus polyglottos）是6月和7月蚊子取食的主要宿主，但在8月，北美红雀（Cardinalis cardinalis）成为了主要宿主。饲料比例分析显示，家朱雀（Haemorhous mexicanus）、美洲知更鸟（Turdus migratorius）、北模仿鸟、北美红雀、白翅哀鸽（Zenaida asiatica）和哀鸽（Zenaida macroura）被过度利用。相对于可得性而言，大嘴乌鸦（Quiscalus mexicanus）、冠蓝鸦（Cyanocitta cristata）和卡罗来纳鹪鹩（Thryothorus ludovicianus）未被充分利用。储存宿主能力计算表明，北模仿鸟和北美红雀是研究区域内的主要扩增宿主。这些数据确定了在得克萨斯州中东部促成WNV动物间扩增的主要鸟类物种，并表明大量取食中等易感性宿主且不叮咬人类可能限制了该地区的疫情。
