Seneghini et al.
Extraneurological presentations of tick-borne encephalitis virus: A rare case of TBEV-associated myocarditis with fever and bicytopenia and a systematic literature review. Case Rep Infect Dis. 2026;2026:3051689. doi:10.1155/2026/3051689.
Infection with tick-borne encephalitis (TBE) virus typically follows a biphasic course, characterized by fever and headache during the initial phase and central nervous system involvement in the second phase. Extraneurological manifestations such as hepatitis, myositis, and thrombocytopenia are uncommon.
A case of myocarditis was reported in a 77-year-old patient from eastern Switzerland who had not received TBE vaccination. The patient presented to the emergency department with acute chest pain three weeks after a tick bite. Laboratory findings revealed moderate neutropenia and thrombocytopenia. Cardiac biomarkers and hepatic enzymes were mildly elevated. The initial electrocardiogram demonstrated mild sinus bradycardia. Blood cultures were negative for bacterial growth, and extensive viral testing yielded negative results.
Early TBE virus infection was suspected. Serological testing showed positive IgM antibodies, followed by seroconversion to high IgG titers, supporting recent infection. The authors concluded that there was a strong causal association between acute myocarditis and TBE virus infection in this case.
A review of the literature indicated that myocarditis has also been reported in association with other flavivirus infections. Although extraneurological manifestations of TBE virus infection remain rare, awareness of these atypical presentations is important to prevent complications and ensure appropriate patient management.