[Effect of the physiological state of ticks on the intensity of tick-borne encephalitis virus replication in them].

The features of tick-borne encephalitis (TBE) virus reproduction in Ixodes ricinus and Dermacentor anderson ticks were studied in relation to the age of ticks, duration of fasting, feeding, and conditions of keeping the ticks before and after the experiment. Parenteral infection of ticks at various intervals after molting showed that the most favourable conditions for reproduction, survival, transphase and transovarial transmission of the virus occurred when the virus was given to the ticks in the first days after the period of postlarval development followed by feeding the vectors on vertebrates. In this case, owing to increased metabolic activity and intensive organogenesis and histogenesis, the virus persisted in ticks in high titers till the moment of oviposition and penetrated into the egg batch. When the virus was inoculated into old exhausted females (8-18 months) virus titers in ticks were low and penetration of the virus into the egg batch was irregular.