Tick-Borne Encephalitis in Slovenia: Data from a Questionnaire Survey

There has been a marked increase in the incidence of tick-borne encephalitis (TBE) in the last two decades, with new foci of the disease evolving. TBE is endemic in Slovenia, and the incidence rate is one of the highest in the European Union. A survey of notified TBE cases started in 1999, aiming to collect additional epidemiological data that are not available through the usual notification system. From 1999 to 2009, a short, anonymous, self-administered questionnaire was sent to 2779 notified TBE cases. The response rate was 69.5%. The willingness to respond was higher in those over 60 years of age, but did not differ by gender. In all, 1564 (82.3%) of the responders had a tick bite on one or multiple sites on the body. Age and gender influenced the location of the tick bite: males patients most often had the tick located on the torso, and females had them on the legs. Ticks located on the head and neck were significantly higher in preschool children compared to school children and adults. The estimated duration of tick attachment was less than 6 h in 23.5% of TBE cases. Long attachments (more than 24 h) were reported by only 10% of the patients. The tick bite occurred while the TBE patients were engaged in leisure time activities (sports or camping, 32.8%), mushroom or berry picking (30.2%), or farming (23.3%). Almost two-thirds of TBE patients reported that they had practiced at least one of the recommended preventive measures, most frequently self-inspection, and least often repellent use. The patients were asked to disclose the most probable geographical location of the TBE viral (TBEV) infection. Maps were created on a county level and showed that the risk of TBE is widespread, with few counties unaffected. The counties located in the northern and the central areas had the highest risk of TBEV infection.