FOLLOW-UP STUDIES OF TICK-BORNE ENCEPHALITIS (ECOLOGICAL, EPIDEMIOLOGICAL AND EXPERIMENTAL LABORATORY STUDIES)
Final technical rept.
VIENNA UNIV (AUSTRIA) HYGIENE INST
Pagination or Media Count:
In field studies 27 virus strains were isolated from ticks. A focus of TBE virus was found considerably further west than any other focus previously detected. Sera of small mammals showed a low incidence and sera of game showed a high incidence of antibodies to TBE virus. Virus strain could be rapidly identified with fluorescent antibodies. The innate resistance to TBE virus of Mus musculus spicilegus is probably due to a single dominant gene. The mouse brain lipid capable of inhibiting hemagglutination of TBE virus is most probably phosphatydilinositol-diphosphate. Its full action requires the presence of auxiliary lipids containing a trimethyl-ammonium group. Preliminary results indicate that the lipid can also inhibit the virus adsorption onto tissue culture cells. In sera from both the acute stage of TBE and from convalescence complement-fixing antibodies were predominantly found in the 7 S gamma globulin fraction. From 39 persons 38 still had complement-fixing and all had hemagglutination-inhibiting antibodies 6-9 years after overt TBE. Continuous propagation of a TBE virus strain led to overattenuation of the virus. In 1966, 136 TBE cases from Austria and 5 cases from Western Germany were diagnosed.
- Medicine and Medical Research