A UK report details six locally acquired cases of tick-borne encephalitis (TBE) since 2019, with two probable cases in 2025. One 2025 case was associated with Dartmoor and another with the Outer Hebrides and Peak District.
Infected ticks have been detected in Thetford Forest, Hampshire/Dorset, and the North Yorkshire Moors. The geographical spread suggests that TBEV-competent tick populations are not confined to the original foci. The lack of a recalled bite in one 2025 case highlights the diagnostic challenge.
Diagnostic classification is further complicated by serological cross-reactivity with Louping Ill Virus (LIV). Environmental conditions favor the persistence and spread of TBEV. Vaccination is recommended only for at-risk groups, but local cases occur among recreational visitors.
