[Comparative data on the tick-borne encephalitis virus infectiousness of hungry and satiated taiga ticks (based on the results of an immunoenzyme analysis)].

The results of individual investigation of 25,500 Ixodes persulcatus ticks from east Siberia are presented. The ticks were collected from grass, men, and animals before their sticking and after feeding at different intervals. The quantity of positive specimens was 6-11 times higher among the fed ticks hungry ones and averaged 10.36 and 1.85%, respectively, at the first stage due to the higher aggression of the infected females at the first stage and due to viral replication when the tick had feed and its better recognition as the titers increased. The proportion of ticks having high levels of tick-borne encephalitis virus antigen among the fed ticks was also considerably higher. The content of virus antigen increased in proportion with the duration of feeding. There is a moderate correlation (r = 0.59) of the infection index of hungry and fed ticks in different years and in various areas. The findings suggest that the fed ticks should be used as an additional marker for the features of tick-borne encephalitis virus circulation.