Mosquito-borne arboviruses in arctic america
Mclean, D.M.
Medical Biology 53(5): 264-270
1975
ISSN/ISBN: 0302-2137 PMID: 1602 Document Number: 91949
Mosquito-borne arboviruses are prevalent throughout subarctic regions of Canada and Alaska, principally in the boreal forest extending between latitudes 53 and 66 deg N, but they have been identified in tundra regions as far north as 70 deg N. All mosquito-borne agents have been bunyaviruses, comprising principally the snowshoe-hare subtype of California encephalitis virus but also Northway virus. Mosquito vectors comprise several species of Aedes and Culiseta inornata (Will.), all of which have supported replication of the virus of California encephalitis following incubation at 13 deg C or lower temperatures. Isolation of virus from wild-caught larvae points towards transovarial transmission. The principal vertebrate reservoirs of infection are mammals, especially snowshoe hares (Lepus americanus) and ground squirrels (Citellus undulatus). Where the boreal forest merges into prairie grassland at about 53 deg N, Culex tarsalis Coq. becomes prevalent and an alphavirus, the causal agent of western equine encephalitis, is detected more frequently than California encephalitis virus.