{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,2]],"date-time":"2026-07-02T00:19:05Z","timestamp":1782951545646,"version":"3.54.5"},"reference-count":34,"publisher":"MDPI AG","issue":"9","license":[{"start":{"date-parts":[[2025,8,30]],"date-time":"2025-08-30T00:00:00Z","timestamp":1756512000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Microorganisms"],"abstract":"<jats:p>Despite rising global reports of Acanthamoeba keratitis (AK), the incidence of AK in Switzerland remains unknown. This investigator-initiated, retrospective, multicenter study assessed the nationwide incidence of PCR- and\/or culture-positive Acanthamoeba results from January 2010 to December 2023. Data were collected from all tertiary care and large ophthalmological facilities in Switzerland, fully anonymized, and aggregated by month and year. We considered all corneal scraping results, whereby the detection method was specific to local standards. We identified 271 PCR- or culture-positive Acanthamoeba cases over 14 years. Applying the population data from the Federal Statistical Office in Switzerland, this corresponds to a mean incidence of 2.29 cases per million people annually. Infections were most common in summer (87 cases, 32.1%), followed by autumn (74 cases, 27.3%), spring (60 cases, 22.1%), and winter (50 cases, 18.5%). We found no significant change in incidence across the investigated period, p = 0.47. This nationwide study reveals a low but stable incidence of AK in Switzerland, in line with other industrialized countries but well below levels reported in tropical or densely populated regions such as India or Egypt. Seasonal variation supports the influence of environmental exposure and underscores the importance of preventive measures during warmer months.<\/jats:p>","DOI":"10.3390\/microorganisms13092032","type":"journal-article","created":{"date-parts":[[2025,9,1]],"date-time":"2025-09-01T13:27:44Z","timestamp":1756733264000},"page":"2032","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Incidence of Acanthamoeba Keratitis in Switzerland"],"prefix":"10.3390","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0009-0000-9807-9623","authenticated-orcid":false,"given":"Frank","family":"Blaser","sequence":"first","affiliation":[{"name":"Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Felix","family":"Grimm","sequence":"additional","affiliation":[{"name":"Institute of Parasitology, University of Zurich, 8006 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Philipp B.","family":"Baenninger","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Cantonal Hospital Winterthur, 8400 Winterthur, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zisis","family":"Gatzioufas","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, University Hospital Basel, 4056 Basel, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0135-2468","authenticated-orcid":false,"given":"Michael A.","family":"Thiel","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Cantonal Hospital Lucerne, 6000 Lucerne, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Moreno","family":"Menghini","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Institute of Clinical Neurosciences of Southern Switzerland (INSI), Ente Ospedaliero Cantonale (EOC), 6900 Lugano, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Beatrice E.","family":"Frueh","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Bern University Hospital, Inselspital, University of Bern, 3010 Bern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Konrad","family":"Muehlethaler","sequence":"additional","affiliation":[{"name":"Institute for Infectious Diseases, University of Bern, 3012 Bern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Marco","family":"Alder","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Cantonal Hospital St. Gallen, 9007 St. Gallen, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kattayoon","family":"Hashemi","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, University of Lausanne, Jules-Gonin Eye Hospital, Fondation Asile des Aveugles, 1004 Lausanne, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ren\u00e9","family":"Brouillet","sequence":"additional","affiliation":[{"name":"Institute of Microbiology, University of Lausanne, 1015 Lausanne, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5025-3856","authenticated-orcid":false,"given":"Horace","family":"Massa","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, University Hospital Geneva, University of Geneva, 1205 Geneva, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Manolito L.","family":"Finger","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Cantonal Hospital Fribourg, 1752 Fribourg, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-6907-1112","authenticated-orcid":false,"given":"Christoph","family":"Tappeiner","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, Pallas Klinik, 4600 Olten, Switzerland"},{"name":"Department of Ophthalmology, University Hospital Essen, University Duisburg-Essen, 45147 Essen, Germany"},{"name":"Medical Faculty, University of Bern, 3012 Bern, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9768-8301","authenticated-orcid":false,"given":"Anthia","family":"Papazoglou","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland"},{"name":"Department of Ophthalmology, Cantonal Hospital Aarau, 5000 Aarau, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Florentina Joyce","family":"Freiberg","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, City Hospital Triemli, 8055 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9529-3317","authenticated-orcid":false,"given":"Gilbert","family":"Greub","sequence":"additional","affiliation":[{"name":"Service of Microbiology, University Hospital of Lausanne, 1005 Lausanne, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5431-4991","authenticated-orcid":false,"given":"Daniel","family":"Barthelmes","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7431-1774","authenticated-orcid":false,"given":"Sandrine A.","family":"Zweifel","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2037-4766","authenticated-orcid":false,"given":"Sadiq","family":"Said","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland"},{"name":"Augenklinik Wettingen, 5430 Wettingen, Switzerland"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,8,30]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Berrilli, F., Montalbano Di Filippo, M., Guadano-Procesi, I., Ciavurro, M., and Di Cave, D. 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