Central European Tick-Borne Encephalitis: Assessment of Risk for Persons in the Armed Services and Vacationers

摘要

The tick-borne encephalitis (TBE) viruses are a subgroup on the antigenically closely related group B togaviruses (flaviviuruses) that produce a spectrum of clinical manifestations ranging from asymptomatic infection to severe disease and death. This infection is seen in areas where the tick Ixodes ricinus is distributed and this species acts as the vector for infection. Risk factors for infection include being male, being 20-40 years old, and having occupational exposure to forested areas. Recent reports by the media of potential death in the form of virus-bearing ticks, together with the availability of an effective vaccine (FSME-Immune Inject; Immuno, Vienna) and a national immunization program in Austria have generated interest in the American military command of Central Europe. This interest is focused on the risk of morbidity and mortality for American service members living and training in areas endemic for TBE in Central Europe. In order to quantify risk of infection and disease for American service members, we studied a military unit that trains extensively in areas of Central Europe thought to be endemic for TBE. A cross-sectional survey was performed by using questionnaire data, serological evidence of prior infection with TBE, and review of medical records and hospital discharge diagnoses for the past 14 years.