{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,10]],"date-time":"2026-07-10T05:13:18Z","timestamp":1783660398627,"version":"3.55.0"},"reference-count":47,"publisher":"MDPI AG","issue":"7","license":[{"start":{"date-parts":[[2026,7,8]],"date-time":"2026-07-08T00:00:00Z","timestamp":1783468800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100004319","name":"Pfizer","doi-asserted-by":"crossref","id":[{"id":"10.13039\/100004319","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Pathogens"],"abstract":"<jats:p>TBEV is a major cause of viral central nervous system infections in Europe, with heterogeneous geographical distribution and substantial underdiagnosis in low-incidence regions. This study aimed to evaluate the validity of regional TBE risk classification in Poland by combining surveillance-based incidence data with serological markers of TBEV exposure. Plasma samples from 5541 blood donors residing in nine regions were tested by anti-TBEV IgG ELISA, followed by confirmatory VNT, IFA, and anti-NS1 IgG ELISA to differentiate infection-induced from vaccine-induced antibodies. Regions were classified based on average TBE incidence registered in surveillance systems in 2015\u20132019. Overall, 272 (4.9%) donors were positive in TBEV IgG ELISA and 177 (3.2%) also in a confirmatory assay. Seroprevalence expressed by markers consistent with past TBEV infection (anti-NS1 IgG) was estimated at 0.13% (95% CI 0.05\u20130.26%), ranging from 0.0% to 0.33% by voivodeship, whereas vaccine-induced immunity accounted for the majority of samples with detected specific antibodies (3.1%). Surprisingly, seroprevalence in a highly affected region (0.29%) was at the same level as in one that was less affected (0.33%). Moreover, all except one seropositive donor lived in urban areas. In four out of nine voivodeships, no anti-NS1 TBEV IgG was detected. By utilising precise laboratory algorithms, we demonstrated a much lower seroprevalence that estimated from prior research relying on screening tests. In addition, we confirmed low vaccination coverage. Integrating sero-epidemiological data with surveillance systems may improve risk assessment and inform targeted prevention strategies.<\/jats:p>","DOI":"10.3390\/pathogens15070720","type":"journal-article","created":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T11:55:32Z","timestamp":1783598132000},"page":"720","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Reassessing Regional Tick-Borne Encephalitis Endemicity in Poland Through Seroprevalence Analysis in Blood Donors, 2021\u20132022"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-3665-5765","authenticated-orcid":false,"given":"Katarzyna W.","family":"Pancer","sequence":"first","affiliation":[{"name":"National Institute of Public Health NIH-NRI, Chocimska 24, 00-791 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Magdalena","family":"Rosi\u0144ska","sequence":"additional","affiliation":[{"name":"National Institute of Public Health NIH-NRI, Chocimska 24, 00-791 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Gerhard","family":"Dobler","sequence":"additional","affiliation":[{"name":"Bundeswehr Institute of Microbiology, 80937 Munich, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9746-2003","authenticated-orcid":false,"given":"Daniel","family":"Rabczenko","sequence":"additional","affiliation":[{"name":"National Institute of Public Health NIH-NRI, Chocimska 24, 00-791 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Agnieszka","family":"Ko\u0142akowska-Kulesza","sequence":"additional","affiliation":[{"name":"National Institute of Public Health NIH-NRI, Chocimska 24, 00-791 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3702-1297","authenticated-orcid":false,"given":"Beata","family":"Gad","sequence":"additional","affiliation":[{"name":"National Institute of Public Health NIH-NRI, Chocimska 24, 00-791 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2026-7293","authenticated-orcid":false,"given":"Anna","family":"Pozna\u0144ska","sequence":"additional","affiliation":[{"name":"National Institute of Public Health NIH-NRI, Chocimska 24, 00-791 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Piotr","family":"Grabarczyk","sequence":"additional","affiliation":[{"name":"Department of Virology, Institute of Heamatology and Transfusion Medicine, 00-791 Warsaw, Poland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,8]]},"reference":[{"key":"ref_1","first-page":"387","article-title":"Meningitis and encephalitis in Poland in 2021","volume":"77","year":"2023","journal-title":"Prz. 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Dis."}],"container-title":["Pathogens"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2076-0817\/15\/7\/720\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,10]],"date-time":"2026-07-10T04:19:17Z","timestamp":1783657157000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2076-0817\/15\/7\/720"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,8]]},"references-count":47,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["pathogens15070720"],"URL":"https:\/\/doi.org\/10.3390\/pathogens15070720","relation":{},"ISSN":["2076-0817"],"issn-type":[{"value":"2076-0817","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,8]]}}}