{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,23]],"date-time":"2026-04-23T10:49:54Z","timestamp":1776941394732,"version":"3.51.4"},"reference-count":17,"publisher":"MDPI AG","issue":"5","license":[{"start":{"date-parts":[[2026,4,23]],"date-time":"2026-04-23T00:00:00Z","timestamp":1776902400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Viruses"],"abstract":"<jats:p>Despite serological evidence of tick-borne encephalitis virus (TBEV) circulation in Belgian animals since 2007, confirmed autochthonous human infection was only first documented in 2020. We review the current national epidemiologic situation and investigate a household cluster of confirmed autochthonous cases identified in 2025. A cohabiting couple experienced a near-simultaneous onset of meningoencephalitis and tested positive for TBEV-specific IgM and IgG, with confirmation by PRNT90. One patient reported a recent tick bite, and both patients reported consumption of unpasteurized milk and goat cheese, suggesting possible alimentary transmission. The identification of Case 2, who lacked neurological symptoms at presentation and was only tested due to the index case, illustrates the risk of missed diagnoses and supports the notion that human TBEV infection is likely underdiagnosed in Belgium. These findings underscore the need to increase clinical awareness, strengthen surveillance, and reinforce prevention strategies. TBE should be considered in the differential diagnosis of patients presenting with non-specific fever or neurological syndromes such as meningoencephalitis, particularly during the spring-to-autumn tick activity season.<\/jats:p>","DOI":"10.3390\/v18050491","type":"journal-article","created":{"date-parts":[[2026,4,23]],"date-time":"2026-04-23T10:10:17Z","timestamp":1776939017000},"page":"491","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["A Household Cluster of Tick-Borne Encephalitis in Belgium in 2025: Is the Epidemiology Evolving?"],"prefix":"10.3390","volume":"18","author":[{"given":"H\u00e9l\u00e8ne","family":"Boogaerts","sequence":"first","affiliation":[{"name":"Department Microbiology, Hospital Oost-Limburg, 3600 Genk, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Janne","family":"Tollenaere","sequence":"additional","affiliation":[{"name":"Department of Neurology, Hospital Oost-Limburg, 3600 Genk, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Kim","family":"Bekelaar","sequence":"additional","affiliation":[{"name":"Department of Neurology, Hospital Oost-Limburg, 3600 Genk, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Els","family":"Oris","sequence":"additional","affiliation":[{"name":"Department Microbiology, Hospital Oost-Limburg, 3600 Genk, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sarah","family":"Resseler","sequence":"additional","affiliation":[{"name":"Department Microbiology, Hospital Oost-Limburg, 3600 Genk, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Baptist","family":"Declerck","sequence":"additional","affiliation":[{"name":"Department Microbiology, Hospital Oost-Limburg, 3600 Genk, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7545-4360","authenticated-orcid":false,"given":"Dorien Van den","family":"Bossche","sequence":"additional","affiliation":[{"name":"Institute of Tropical Medicine, 2000 Antwerp, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7294-6319","authenticated-orcid":false,"given":"Marjan","family":"Van Esbroeck","sequence":"additional","affiliation":[{"name":"Institute of Tropical Medicine, 2000 Antwerp, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8082-6587","authenticated-orcid":false,"given":"Deborah","family":"Steensels","sequence":"additional","affiliation":[{"name":"Department Microbiology, Hospital Oost-Limburg, 3600 Genk, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,4,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"1861","DOI":"10.1016\/S0140-6736(08)60800-4","article-title":"Tick-borne encephalitis","volume":"371","author":"Lindquist","year":"2008","journal-title":"Lancet"},{"key":"ref_2","first-page":"2200543","article-title":"Spatiotemporal spread of tick-borne encephalitis in the EU\/EEA, 2012 to 2020","volume":"28","author":"Haussig","year":"2023","journal-title":"Eurosurveillance"},{"key":"ref_3","first-page":"4","article-title":"Comparative Tick Borne Encephalitis (Virus) Surveillance in Belgium 2009\u20132015: Experiences with Diagnostic Tests, Sentinel Species and Surveillance Designs","volume":"1","author":"Roelandt","year":"2017","journal-title":"J. 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Dis."},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Gonzalez, G., Bournez, L., Moraes, R.A., Marine, D., Galon, C., Vorimore, F., Cochin, M., Nougair\u00e8de, A., Hennechart-Collette, C., and Perelle, S. (2022). A One-Health Approach to Investigating an Outbreak of Alimentary Tick-Borne Encephalitis in a Non-endemic Area in France (Ain, Eastern France): A Longitudinal Serological Study in Livestock, Detection in Ticks, and the First Tick-Borne Encephalitis Virus Isolation and Molecular Characterisation. Front. Microbiol., 13.","DOI":"10.3389\/fmicb.2022.863725"}],"container-title":["Viruses"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1999-4915\/18\/5\/491\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,4,23]],"date-time":"2026-04-23T10:15:30Z","timestamp":1776939330000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1999-4915\/18\/5\/491"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,4,23]]},"references-count":17,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2026,5]]}},"alternative-id":["v18050491"],"URL":"https:\/\/doi.org\/10.3390\/v18050491","relation":{},"ISSN":["1999-4915"],"issn-type":[{"value":"1999-4915","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,4,23]]}}}