{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,23]],"date-time":"2026-01-23T15:27:33Z","timestamp":1769182053440,"version":"3.49.0"},"reference-count":38,"publisher":"MDPI AG","issue":"2","license":[{"start":{"date-parts":[[2026,1,23]],"date-time":"2026-01-23T00:00:00Z","timestamp":1769126400000},"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>To evaluate the epidemiology of herpetic keratitis over a 15-year period at a tertiary care center in Switzerland, focusing on the relative incidence of herpes simplex virus (HSV)-1, HSV-2, and varicella zoster virus (VZV), gender distribution, and co-infections, we conducted a retrospective single-center analysis of polymerase chain reaction (PCR) assays from corneal and conjunctival scrapings of suspected herpetic keratitis at a tertiary referral hospital. Patient demographics, viral spectra, and microbiological co-infections were assessed. Between 2010 and 2025, we identified 9954 PCR assays from 2892 patients, with 482 samples testing positive for herpesvirus. HSV-1 was the most frequent pathogen (328 of 3358, 9.8%), followed by VZV (143 of 3112, 4.6%), HSV-2 (9 of 3290, 0.27%), and CMV (2 of 194, 1.0%). Triplet testing (simultaneous HSV-1, HSV-2, and VZV-PCR) enabled direct comparisons of relative incidence rates. We found 2913 triplet testing results, with a relative distribution in positive results of 65.4% for HSV-1, 32.5% for VZV, and 2.1% for HSV-2. HSV-1 keratitis had a statistically significant higher incidence in men (58.9%, p = 0.0044), while no sex difference was detected for VZV (47.9%, p = 0.6683), HSV-2 (33.3%, p = 0.5078), or CMV (100%, p = 0.500). Bilateral infections were present in two patients, and co-infections were detected as follows: 8 cases of HSV-1\/VZV co-detection, 3 cases of Acanthamoeba, and 15 of fungi. HSV-1 was the overwhelmingly dominant cause of herpetic keratitis at our institution, occurring more than twice as frequently as VZV and vastly outnumbering HSV-2. The statistically significant higher incidence in men in HSV-1 keratitis suggests possible biological or sociodemographic influences, whereas co-infections highlight the complexity of corneal pathology in a referral setting. These findings underscore the importance of multiplex PCR testing for accurate pathogen detection and provide insights into the epidemiologic landscape of herpetic keratitis.<\/jats:p>","DOI":"10.3390\/microorganisms14020268","type":"journal-article","created":{"date-parts":[[2026,1,23]],"date-time":"2026-01-23T13:55:34Z","timestamp":1769176534000},"page":"268","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Viral Spectrum of Herpetic Keratitis: A 15-Year Retrospective Analysis from Switzerland"],"prefix":"10.3390","volume":"14","author":[{"given":"Muntadher","family":"Al Karam","sequence":"first","affiliation":[{"name":"Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"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":[{"role":"author","vocabulary":"crossref"}]},{"given":"Anahita","family":"Bajka","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland"},{"name":"Talacker Augenzentrum Z\u00fcrich (TAZZ), 8001 Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Irene","family":"Voellmy","sequence":"additional","affiliation":[{"name":"Institute of Medical Virology, University of Zurich, 8057 Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-0384-0000","authenticated-orcid":false,"given":"Michael","family":"Huber","sequence":"additional","affiliation":[{"name":"Institute of Medical Virology, University of Zurich, 8057 Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"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":[{"role":"author","vocabulary":"crossref"}]},{"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":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0009-0000-9807-9623","authenticated-orcid":false,"given":"Frank","family":"Blaser","sequence":"additional","affiliation":[{"name":"Department of Ophthalmology, University Hospital Zurich, University of Zurich, 8091 Zurich, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2026,1,23]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"67","DOI":"10.18773\/austprescr.2018.016","article-title":"Common Eye Infections","volume":"41","author":"Watson","year":"2018","journal-title":"Aust. 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