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The following is a summary of “Tick-borne encephalitis in adults in Denmark: a nationwide prospective cohort study from 2015 to 2023,” published in the March 2025 issue of Journal of Neurology by Florescu et al.  

Researchers conducted a retrospective study to assess the incidence, testing, and clinical outcomes of tick-borne encephalitis (TBE) in Danish adults.  

They conducted a nationwide prospective cohort study of adults hospitalized with TBE at infectious disease departments in Denmark from 2015 to 2023. They included age- and sex-matched cohort of herpes simplex virus type 1 (HSV-1) encephalitis patients for outcome comparison.  

The results showed 52 patients with TBE, a median age of 50 years, and 32/52 (62%) were men. Only 1/52 (2%) were fully vaccinated, and 29/52 (56%) were infected in Denmark. Upon admission, 25/52 (48%) had meningitis, 27/52 (52%) had encephalitis, and 3/52 (6%) had additional myelitis or radiculitis. ICU admission occurred in 6/52 (12%), and 2/52 (4%) died, both linked to comorbidities and older age. At 3 months, 16/50 (32%) had an unfavorable outcome versus 39/52 (75%) in the HSV-1 cohort. At 6 months or later, common residual symptoms were headache, cognitive impairment, and fatigue. TBE incidence rose from 0.03/100,000 in 2015 to 0.48/100,000 in 2023, test rates from 5.5/100,000 to 14.4/100,000, and positivity from 0.6% to 3.3%.  

Investigators found an increasing incidence of TBE in Denmark, with clinical characteristics and outcomes similar to reports from other European countries.  

Source: link.springer.com/article/10.1007/s00415-025-12986-5