Tick-borne encephalitis: from tick surveillance to the first confirmed human cases, the United Kingdom, 2015 to 2023

TY - JOUR

T1 - Tick-borne encephalitis

T2 - from tick surveillance to the first confirmed human cases, the United Kingdom, 2015 to 2023

AU - Callaby, Helen

AU - Beard, Kate R.

AU - Wakerley, Dominic

AU - Lake, Mary Alexandra

AU - Osborne, Jane

AU - Brown, Kevin

AU - Wand, Nadina

AU - Warner, Jenny

AU - Holding, Maya

AU - Davies, Nicholas W.S.

AU - Proudfoot, Malcolm

AU - Semper, Amanda

AU - Brooks, Tim

AU - Petridou, Christina

AU - Houlihan, Catherine F.

AU - Rampling, Tommy

AU - Warrell, Clare E.

AU - Gordon, N. Claire

AU - Thorne, Christopher

AU - Brittain-Long, Robin

AU - Bangash, Fahed

AU - Stafford, Adam

AU - Bresges, Carolin

AU - Underwood, Jonathan

AU - Dervisevic, Samir

AU - Graham, Jonathan

AU - Andersson, Monique I.

N1 - Publisher Copyright: © 2025 European Centre for Disease Prevention and Control (ECDC). All rights reserved.

PY - 2025/2/6

Y1 - 2025/2/6

N2 - Background: Tick-borne encephalitis virus (TBEV) is a flavivirus spread by ticks and can cause tick-borne encephalitis (TBE) in humans. Previously, TBE has been reported in returning travellers in the United Kingdom (UK), but in 2019 and 2020, two probable cases of TBE acquired in the UK were identified. Aim: The aim of this study was to investigate TBE cases in the UK between 2015 and 2023, describing the incidence, place and mode of acquisition and diagnostic process. Methods: A retrospective review of possible, probable and confirmed cases of TBE diagnosed by the Rare and Imported Pathogens Laboratory (RIPL) between January 2015 and December 2023 was performed. For cases identified in 2022 and 2023, clinical data were collected for enhanced surveillance using structured case record forms. Laboratory diagnosis is reviewed and described. Results: We identified 21 cases: three possible, seven probable and 11 confirmed cases. Of these, 12 were between January 2022 and December 2023: three possible, three probable and six confirmed cases. Two confirmed TBE cases had definite or highly probable acquisition in the UK, in June and August 2022, respectively. One of the possible cases had definite UK acquisition. Cases typically have a biphasic presentation, with encephalitis in the second phase. Conclusion: Clinicians should be aware of the possibility of TBE when the cause for encephalitis is not identified, even in the absence of travel to previously identified endemic regions.

AB - Background: Tick-borne encephalitis virus (TBEV) is a flavivirus spread by ticks and can cause tick-borne encephalitis (TBE) in humans. Previously, TBE has been reported in returning travellers in the United Kingdom (UK), but in 2019 and 2020, two probable cases of TBE acquired in the UK were identified. Aim: The aim of this study was to investigate TBE cases in the UK between 2015 and 2023, describing the incidence, place and mode of acquisition and diagnostic process. Methods: A retrospective review of possible, probable and confirmed cases of TBE diagnosed by the Rare and Imported Pathogens Laboratory (RIPL) between January 2015 and December 2023 was performed. For cases identified in 2022 and 2023, clinical data were collected for enhanced surveillance using structured case record forms. Laboratory diagnosis is reviewed and described. Results: We identified 21 cases: three possible, seven probable and 11 confirmed cases. Of these, 12 were between January 2022 and December 2023: three possible, three probable and six confirmed cases. Two confirmed TBE cases had definite or highly probable acquisition in the UK, in June and August 2022, respectively. One of the possible cases had definite UK acquisition. Cases typically have a biphasic presentation, with encephalitis in the second phase. Conclusion: Clinicians should be aware of the possibility of TBE when the cause for encephalitis is not identified, even in the absence of travel to previously identified endemic regions.

UR - https://www.scopus.com/pages/publications/85217629564

U2 - 10.2807/1560-7917.ES.2025.30.5.2400404

DO - 10.2807/1560-7917.ES.2025.30.5.2400404

M3 - Article

C2 - 39916608

SN - 1025-496X

VL - 30

JO - Eurosurveillance

JF - Eurosurveillance

IS - 5

M1 - 2400404

ER -