RESUMO
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).
Assuntos
Culicidae/microbiologia , Vírus da Encefalite/isolamento & purificação , Encefalite por Arbovirus , Encefalite da Califórnia , Aedes/microbiologia , Animais , Anticorpos Antivirais/análise , Antígenos Virais/análise , Canadá , Testes de Fixação de Complemento , Testes de Inibição da Hemaglutinação , Lagomorpha/imunologia , Camundongos , Testes de Neutralização , Peroxidases , Roedores/imunologia , Glândulas Salivares/microbiologia , Sciuridae/imunologia , Estações do Ano , Replicação ViralRESUMO
Virions were identified by electron microscopic observation of unconcentrated extracts of feces obtained from 55 (33%) of 167 children aged 3 weeks to 5 years who were hospitalized with acute gastroenteritis at Children's Hospital, Vancouver between January and December 1976. Morphologic types included 30 rotavirus, 15 adenovirus, 5 astrovirus and 5 picornavirus-like particles.