[Dissemination of arboviruses transmitted by mosquitoes in Czechoslovakia and the epidemiologic consequences]

Abstract

In Czechoslovakia three new arboviruses isolated from mosquitoes were discovered--Tahyna, Calovo and Lednice--which circulate on our territory. The submitted paper summarizes the results of long-term oecological studies of these viruses, in particular their vectors and hosts. The differences between individual viruses in this respect are very marked and from them also differences in the circulation of these viruses follow. There are also very marked differences in their distribution, as apparent from the isolation of 83 strains of the viruses from more than 263,000 mosquitoes 61 of whom belong to the Tahyna virus, 15 to the Calovo virus and 7 to the Lednice virus. The Tahyna virus was isolated from 8 mosquito species, virus Calovo and Lednice only from a single one. While vectors of the Tahyna virus, mainly from the genus Aedes, are widespread as far as biotypes, radius of action and hosts are concerned, and they attack man, vectors of the Calovo and Lednice virus--Anopheles maculipennis s.l. and Culex modestus--have much more restricted activities as regards biotype, radius of action, hosts and contact with humans. The above reasons explain also the high prevalence of antibodies against the Tahyna virus in the population living in the natural focus of this virus and the relatively high number of diseases, in particular in children, where every seventh influenza--like case and every fifth case with manifestations of meningoencephalitis can be ascribed to this virus. The low prevalence of antibodies the Calovo virus in humans is explained by the marked zoophilia of vectors of this virus.(ABSTRACT TRUNCATED AT 250 WORDS)