[Demonstration of the tick-borne encephalitis virus by a solid-phase immunoenzyme method in materials from natural foci].

Large-scale examinations of specimens from natural foci of tick-borne encephalitis (TBE) demonstrated that sensitivity of solid-phase enzyme immunoassay (EIA) in detecting TBE virus antigen was as high as that of the fluorescent antibody technique. The EIA takes less time and may be used for examinations of specimens after a preliminary passage in cell cultures. The EIA was also shown to be highly effective in the detection of TBE virus antigen in the cerebral tissue of patients post mortem and in the confirmation of the clinical diagnosis.

[Biological properties of tick-borne encephalitis strains isolated in different parts of its geographic range].

A comparative study of over 200 tick-borne encephalitis (TBE) virus strains isolated from patients and ticks in different regions varying in the proportion of severe clinical forms of TBE was carried out. The strains were tested for their pathogenicity for white mice, cytopathic and plaque-forming properties as well as for the interferon-inducing capacity in SPEV cells. All the strains were found to be highly neurovirulent for mice, to produce plaques with diameters varying form less than 1 to 10 mm, and to induce interferon production in SPEV cell.