Jansson, Sofia2025-07-162025-07-162025-07-16https://hdl.handle.net/2077/88817Background: Tick-borne encephalitis (TBE) is an increasing public health challenge in Sweden as well as the rest of Europe. The number of reported cases continues to rise, including in regions where TBE has not previously been observed. Transmission occurs through bites from infected ticks and can lead to serious neurological symptoms with a risk of long-term sequelae. Research questions: Have there been any changes in the patient population hospitalized for TBE at the Department of Infectious Diseases in Gothenburg between the periods 2014–2015 and 2023–2024? Are there any differences in gender and age distribution? Are there any differences in underlying immunosuppression, disease severity, length of hospital stay, and mortality? Has the proportion of vaccinated patients changed? Materials and methods: This retrospective cohort study compares two groups of TBE patients treated at the Department of Infectious Diseases in Sahlgrenska University Hospital, Gothenburg, during 2014–2015 and 2023–2024. Patients were identified using ICD-10 code A84.1. Variables such as age, sex, length of stay, disease severity, vaccination status, course of illness, immunosuppression, and mortality were analyzed. Results: A total of 21 patients were included in the study: seven during 2014–2015 and fourteen during 2023–2024. The results showed greater variation in disease severity in the latter period, as well as an increased proportion of vaccinated patients. There was also a trend toward shorter hospital stays and greater age variation during 2023–2024. Conclusion and implications: The findings suggest changes in disease presentation and vaccination status over time. Vaccinated patients tended to experience monophasic courses of illness, indicating that vaccination may influence disease progression but does not always prevent infection. The study highlights the importance of continued vaccination efforts and standardized diagnostics. Further research is needed to confirm these trends and inform public health measures.sweTick-borne encephalitis, TBEText