Characteristics of some tick--borne encephalitis virus strains isolated in Slovakia

Area of Science:

• Virology
• Arthropod-borne Diseases
• Epidemiology

Background:

• Tick-borne encephalitis (TBE) is a significant neurological disease transmitted by ticks.
• Understanding the genetic and pathogenic diversity of TBE virus is crucial for public health.
• Previous studies have indicated geographical and host-related variations in TBE virus strains.

Purpose of the Study:

• To characterize TBE virus strains isolated in Slovakia between 1974 and 1978.
• To compare the properties of TBE virus strains originating from different tick vectors.
• To assess the pathogenicity and biological characteristics of these Slovak TBE virus isolates.

Main Methods:

• Isolation and characterization of TBE virus strains from Slovakian ticks and rodents.
• Assessment of cytopathic effects in cell cultures.
• Determination of sensitivity to heat (50°C) and chemical agents (2 M urea).
• Evaluation of pathogenicity through white mouse models.

Main Results:

• Significant differences in pathogenic properties were observed between TBE virus strains.
• Strains isolated from Ixodes ricinus ticks exhibited distinct characteristics compared to those from Clethrinomys glareolus.
• TBE virus strains isolated from Clethrinomys glareolus (Skalica strains) demonstrated decreased virulence in white mice.

Conclusions:

• The study highlights the heterogeneity of TBE virus strains circulating in Slovakia.
• Vector-host interactions appear to influence the pathogenic profile of TBE virus.
• The Skalica TBE virus strains represent a potentially less virulent variant, possibly due to spontaneous mutation or adaptation.