McLean D M, Bergman S K, Gould A P, Grass P N, Miller M A, Spratt E E
Am J Trop Med Hyg. 1975 Jul;24(4):676-84. doi: 10.4269/ajtmh.1975.24.676.
California encephalitis (CE) virus (snowshoe hare subtype) was isolated from 1 of 38 pools comprising 970 unengorged female Aedes canadensis mosquitoes and from 3 of 152 pools containing 5,676 A. communis mosquitoes which were collected in the Yukon Territory, Canada between latitudes 61 and 66 degrees N during June and July 1974. During four summers 1971 through 1974, this virus was recovered from 26 of 648 pools derived from 30,686 mosquitoes of 4 species. Isolation of CE virus from 1 of 109 pools of Aedes sp. larvae collected during May 1974 suggests maintenance of this virus over winter by transovarial transfer. Infectivity has been maintained in Culiseta inornata mosquitoes which were held continuously at 32 degrees F for 138 days. Neutralizing antibodies to CE virus were detected in 705 of 4,913 (14%) mammals collected during summers 1971 through 1974, including 430 of 1,076 (40%) snowshoe hares (Lepus americanus), 266 of 3,610 (7%) ground squirrels (Citellus undulatus) and 9 of 227 (4%) red squirrels (Tamiasciurus hudsonicus).
1974年6月至7月间，在加拿大育空地区北纬61度至66度之间采集的970只未吸血的雌性加拿大伊蚊组成的38个样本池中，有1个样本池分离出加利福尼亚脑炎（CE）病毒（雪兔亚型）；在包含5676只普通伊蚊的152个样本池中，有3个样本池分离出该病毒。在1971年至1974年的四个夏天里，从源自4种共30686只蚊子的648个样本池中，有26个分离出了这种病毒。1974年5月采集的109个伊蚊属幼虫样本池中，有1个分离出CE病毒，这表明该病毒可通过经卵传递越冬。在32华氏度下连续饲养138天的无味库蚊中，该病毒仍保持感染力。在1971年至1974年夏天采集的4913只哺乳动物中，有705只（14%）检测到针对CE病毒的中和抗体，其中包括1076只雪兔（美洲兔）中的430只（40%）、3610只地松鼠（黄鼠）中的266只（7%）和227只红松鼠（美洲红松鼠）中的9只（4%）。
