Srinivasan A, et al. Tick-borne encephalitis in international travelers: a systematic review and vaccine recommendations. J Travel Med. 2025;taaf115. doi:10.1093/jtm/taaf11
Travel-associated tick-borne encephalitis (TBE) cases have not been comprehensively summarized in the scientific literature for more than a decade. To address this gap, the authors conducted a systematic literature review identifying 25 studies that reported a total of 39 laboratory-confirmed international travel-associated TBE cases between 1978 and 2024.
None of the affected travellers had been vaccinated against TBE. The clinical presentation of travel-associated cases was comparable to that of domestically acquired TBE. Of the 34 cases reporting clinical information, 33 (97.1%) required hospitalization. One fatal case was reported, corresponding to a case fatality rate of 2.6%. The median duration of travel was 17 days (range: 3–107 days), with travel occurring predominantly between May and September.
Among the 38 cases for which the destination country was reported, the most frequently visited countries were Austria (n = 8), Russia (n = 7), Sweden (n = 7), Switzerland (n = 6), Germany (n = 5), the Czech Republic (n = 3), and Lithuania (n = 3).
In contrast to the limited number of published cases, the European Centre for Disease Prevention and Control (ECDC) reported 376 international travel-associated TBE cases between 2015 and 2022, out of a total of 22,191 reported TBE cases (1.7%). This discrepancy highlights that only a small fraction of travel-associated TBE cases, typically the most severe or noteworthy, are published in scientific journals. Consequently, published case numbers should be interpreted as indicators of the public health relevance of TBE in travellers rather than as accurate measures of individual travel risk.
The authors identified 32 countries that currently provide recommendations for TBE vaccination for travellers and compiled detailed descriptions of national recommendations, including English translations, for ease of reference. However, in many cases, the term “TBE-endemic region” was not clearly defined. This lack of clarity may lead to misunderstandings regarding when and where vaccination is recommended, potentially resulting in inadequate protection. The authors emphasize that clearer and more standardized definitions of endemic areas would substantially improve risk communication and vaccination decision-making for travellers.