[The location of the infecting tick bite and the severity of the course of tick-borne encephalitis].

Analysis of 846 epidemiological charts of unvaccinated tick-borne encephalitis patients in the period of 1956-1985 established that in 21% cases the disease resulted from multiple bites of the ticks, in 67.3% it occurred from single bites. In 11.7% of the patients, the bite was denied. Single infecting bites were mostly those of the head and neck (39.2% cases), especially frequent among children (84.9%). The upper part of the body and hands were bitten less frequently (16.7 and 12.5%, respectively). Other sites of the bite were reported in 6-10%. The most complicated pattern of tick-borne encephalitis is observed in case of multiple bites: two-fold increase in mortality rates compared to single bites (23.2 vs. 10.7%) and higher percent of focal forms (72.7 vs. 56.5%). In case of the single bites a certain correlation is observed between the site of the bite and the outcome of the disease: fatal outcomes are most frequent in case of the bites in the axilla, arms (14-16%), head and neck (11.2%), and less frequent in case of the bites in the lower limbs (5.9%) and groin (0). The nature of the infecting bite determines, to a great extent, the pathogenesis and outcome of the disease. The prevention of multiple bites would help considerably to reduce mortality rates.