[Effect of the Tahyña virus on Langat virus persistence in the central nervous system of the mouse].

The features of development of a mixed infection in which one of the infectious agents (Tahyña virus) had a marked immunodepressive activity and the other (Langat virus) caused predominantly asymptomatic course of the disease were studied. Successive infection with these agents increased the severity of the disease (lethality in monoinfection 7-18%, in mixed infection 57%). At the same time the duration of persistence in the brain of mice of Langat virus but not of Tahyña virus increased up to 110 days. It was demonstrated by the method of linear labyrinth that long-term asymptomatic carrier state of Langat virus was accompanied by disorders in the orienting-analysing function of the central nervous system. It is suggested that an increase in the duration of asymptomatic virus carrier state is due to the inhibiting effect of Tahyña virus on the T-dependent mechanisms of virus elimination from the body.