[Isolation of the causative agent of Karelian fever from Aedes sp. mosquitoes]

The results of isolation of an Alphavirus strain from Aedes sp. mosquitoes collected in the focus of Karelian fever are presented. According to the results of serological studies, the isolated strain LEIV-9298 Karelia belongs to the antigenic complex Sindbis-Western equine encephalomyelitis. The appurtenance of the isolated agent to the Alphavirus genus has been confirmed by electron microscopic examinations. A rise of antibody titres to LEIV-9298 Karelia virus in paired sera of subjects with a history of Karelian fever allows it to be considered the causative agent of this disease.