[Tick-borne encephalitis associated with other infections]. / Kleshchevoi entsefalin, assotisiirovannyi s drugimi infektsiiami.

Possibility of mixed infection arising in encounter of agents from different families (virus-virus, virus-bacteria, virus-protozoa) was demonstrated on 103 cases of chronic tick-borne encephalitis (TBE) association with other acute and chronic infection. The addition of influenza, tuberculosis, pyogenic infection in most cases entails a relapse of TBE or promotes a primary-progressive course of the disease. TBE association with rheumatic fever relieves pain symptoms. It is emphasized that mixed infections used to bring suppression of immune reactivity thus necessitating serological and virological monitoring of the disease run.

[Characteristics of tick-borne encephalitis virus strains isolated from patients with chronic diseases of the central nervous system]. / Kharakteristika shtammov virusa kleshchevogo éntsefalita, izolirovannykh ot bol'nykh s khronicheskimi zabolevaniiami tsentral'noi nervnoi sistemy.

Two groups of tick-borne encephalitis (TBE) virus strains were studied: Group 1, 5 strains isolated from patients with chronic TBE with progressive course, Group 2, 13 strains isolated from residents of an endemic locality, with chronic diseases of the CNS (amiotrophic lateral sclerosis, epidemic encephalitis, polyoencephalomyelitis, syringomyelia, etc.). Strains of both groups belong to two serotypes of TBE virus: mid-Siberian and Transbaikal (synonym Aina/1448) and eastern. Group 1 strains were heterogeneous in their virulence, immunogenic and surface properties of the virions. The latter characteristic was demonstrated in studies of elution from macropore glass and sensitivity of hemagglutinin to the effect of detergents (Bridge-96, Tween-80). Eight of 13 Group 2 patients had concurrent diseases (tuberculosis, toxoplasmosis, tumors, etc.). Streptomycin was demonstrated to activate asymptomatic infection with TBE virus in hamsters. It is assumed that isolation of TBE virus from Group 2 patients could be due to activation of persistent infection under the effect of concurrent diseases and drugs.

[Immunological and etiological aspects of a study of the Aina/1448 serotype of the tick-borne encephalitis virus]. / Immunologicheskie i nekotorye étiologicheskie aspekty izucheniia serotipa Aina/1448 virusa kleshchevogo éntsefalita.

Blood sera (1488 specimens) of the human population collected in the zone of isolation of tick-borne encephalitis (TBE) virus strains belonging to the Aina/1448 serotype were tested by the neutralization, hemagglutination-inhibition, agar gel diffusion and precipitation, and complement fixation tests with antigens of the Aina/1448 strain and prototype TBE virus strains representing the eastern and western serotypes. The dominating role of the Aina/1448 serotype in the formation of herd immunity in different areas of the forest-steppe and taiga zones of the Irkutsk region was established. Antibody to the Aina/1448 strain was found in the blood of the normal population and patients with acute and chronic forms of TBE. In TBE patients the percentage of virus-neutralizing antibody to the Aina/1448 strain was significantly higher (36.8%) than in the general population (16.6%). These are differences in the structure of immunity in vaccinees and nonvaccinees with TBE vaccine. Sera from the nonvaccinees reacted with the Aina/1448 strain more frequently, sera of the vaccinees more frequently contained antibody to different serotypes of TBE virus. Diagnostic problems and criteria of evaluation of the local antigenic variants of TBE virus are discussed.