Andreadis Theodore G, Armstrong Philip M, Anderson John F, Main Andrew J
Center for Vector Biology & Zoonotic Diseases, The Connecticut Agricultural Experiment Station , New Haven, Connecticut.
Vector Borne Zoonotic Dis. 2014 Oct;14(10):763-73. doi: 10.1089/vbz.2014.1669.
Cache Valley virus (CVV) is a mosquito-borne bunyavirus (family Bunyaviridae, genus Orthobunyavirus) that is enzootic throughout much of North and Central America. White-tailed deer (Odocoileus virginianus) have been incriminated as important reservoir and amplification hosts. CVV has been found in a diverse array of mosquito species, but the principal vectors are unknown. A 16-year study was undertaken to identify the primary mosquito vectors in Connecticut, quantify seasonal prevalence rates of infection, and define the spatial geographic distribution of CVV in the state as a function of land use and white-tailed deer populations, which have increased substantially over this period. CVV was isolated from 16 mosquito species in seven genera, almost all of which were multivoltine and mammalophilic. Anopheles (An.) punctipennis was incriminated as the most consistent and likely vector in this region on the basis of yearly isolation frequencies and the spatial geographic distribution of infected mosquitoes. Other species exhibiting frequent temporal and moderate spatial geographic patterns of virus isolation within the state included Ochlerotatus (Oc.) trivittatus, Oc. canadensis, Aedes (Ae.) vexans, and Ae. cinereus. New isolation records for CVV were established for An. walkeri, Culiseta melanura, and Oc. cantator. Other species from which CVV was isolated included An. quadrimaculatus, Coquillettidia perturbans, Culex salinarius, Oc. japonicus, Oc. sollicitans, Oc. taeniorhynchus, Oc. triseriatus, and Psorophora ferox. Mosquitoes infected with CVV were equally distributed throughout urban, suburban, and rural locales, and infection rates were not directly associated with the localized abundance of white-tailed deer, possibly due to their saturation throughout the region. Virus activity in mosquitoes was episodic with no consistent pattern from year-to-year, and fluctuations in yearly seasonal infection rates did not appear to be directly impacted by overall mosquito abundance. Virus infection in mosquitoes occurred late in the season that mostly extended from mid-August through September, when adult mosquito populations were visibly declining and were comparatively low. Findings argue for a limited role for vertical transmission for the perpetuation of CVV as occurs with other related bunyaviruses.
卡奇谷病毒（CVV）是一种由蚊子传播的布尼亚病毒（布尼亚病毒科正布尼亚病毒属），在北美洲和中美洲大部分地区呈地方性流行。白尾鹿（弗吉尼亚鹿）被认为是重要的储存宿主和扩增宿主。已在多种蚊子中发现CVV，但主要传播媒介尚不清楚。开展了一项为期16年的研究，以确定康涅狄格州的主要蚊子传播媒介，量化感染的季节性流行率，并根据土地利用情况和白尾鹿种群数量（在此期间大幅增加）确定该州CVV的空间地理分布。从7个属的16种蚊子中分离出CVV，几乎所有这些蚊子都是多化性且嗜哺乳动物的。根据每年的分离频率和受感染蚊子的空间地理分布，尖音库蚊被认为是该地区最稳定且可能的传播媒介。该州其他表现出频繁的时间性和适度的空间地理病毒分离模式的物种包括三带喙库蚊、加拿大伊蚊、骚扰伊蚊和灰黑伊蚊。确立了沃克库蚊、黑尾脉毛蚊和康塔托伊蚊的CVV新分离记录。分离出CVV的其他物种包括四斑按蚊、骚扰柯蚊、盐泽库蚊、日本伊蚊、海滨伊蚊、尖音库蚊、三带喙库蚊、三列伊蚊和凶猛贪蚊。感染CVV的蚊子在城市、郊区和农村地区分布均匀，感染率与白尾鹿的局部丰度没有直接关联，可能是因为它们在整个地区都已饱和。蚊子中的病毒活动是间歇性的，年与年之间没有一致的模式，而且每年季节性感染率的波动似乎并未直接受到总体蚊子数量的影响。蚊子中的病毒感染发生在季节后期，主要从8月中旬持续到9月，此时成年蚊子数量明显下降且相对较少。研究结果表明，与其他相关布尼亚病毒一样，垂直传播在CVV持续存在中所起的作用有限。
