[The circulation of viruses of the California encephalitis and Bunyamwera groups (Bunyaviridae, Bunyavirus) on the northeastern Russian plain]

Abstract

In the Komi ASSR, 102.2 thousand mosquitoes, 207 small mammals, 1487 blood serum specimens from people, 793 cow blood sera, 140 blood serum specimens from reindeer were collected in June-August, 1988. Twenty seven virus strains isolated from mosquitoes were classified into Bunyaviridae family according to the data of electron microscopic studies. Identification of the isolates by CFT and IFA showed 18 of the strains to belong to California encephalitis complex and 9 to Bunyamwera complex. Serological studies by neutralization test demonstrates a high frequency of contact of the human population and domestic animals with viruses of the California complex practically in the entire study area: an average of 45% among human subjects, 48% among cattle and 33% among reindeer. Such high values of the immune portions indicate the activity of the discovered natural foci of this complex. The results for Batai virus from the Bunyamwera complex do not indicate its high activity: approximately 2% of positive findings in human subjects and about 4% in the cattle. The results permit a prognosis of California encephalitis and Bunyamwera complex viruses spread in the northern part of Western Siberia.