{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,12,26]],"date-time":"2025-12-26T02:29:38Z","timestamp":1766716178459,"version":"3.48.0"},"reference-count":35,"publisher":"MDPI AG","issue":"1","license":[{"start":{"date-parts":[[2025,12,25]],"date-time":"2025-12-25T00:00:00Z","timestamp":1766620800000},"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>The recent literature has debunked the widespread hypothesis that viruses are primarily transmitted via droplets and not beyond 1.5 m, and transmission via contact has been downplayed. Hence, an evidence-based revision of the existing isolation guidelines for respiratory viruses was needed. Therefore, a completely new protocol for respiratory virus isolation in terms of personal protective equipment and patient room air purification was evaluated. Isolation relief criteria based on Ct values in follow-up sampling were assessed. A Ct value of &lt;28 was employed as a proxy for potential active replication and associated transmissibility. Between 25% and 50% of patients who tested positive for RSV, HRV, hMPV, or SARS-CoV-2 continued to exhibit high viral loads on day 7 post-initial diagnosis, underscoring the potential for sustained infectivity. Hence, the discontinuation of isolation measures for these patients without follow-up testing may carry a considerable risk of ongoing viral transmission. On the contrary, only 7% of patients positive for Flu and 14% for PIV had a follow-up sample on day 7 with a Ct value of less than 28. Ct values increased more rapidly in influenza, indicating faster viral clearance compared to other respiratory viruses. Based on these results, the policy of a standard 7-day isolation period without follow-up testing could be adopted for influenza-positive patients.<\/jats:p>","DOI":"10.3390\/v18010040","type":"journal-article","created":{"date-parts":[[2025,12,26]],"date-time":"2025-12-26T02:07:58Z","timestamp":1766714878000},"page":"40","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Redesigning Isolation Practices: Evaluation of a Comprehensive Protocol for Respiratory Virus Control Including Cycle Threshold (Ct) Value Dynamics"],"prefix":"10.3390","volume":"18","author":[{"given":"Stefanie","family":"Lemmens","sequence":"first","affiliation":[{"name":"Department of Molecular Microbiology, Ziekenhuis Oost-Limburg, 3600 Genk, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5521-0521","authenticated-orcid":false,"given":"Kevin","family":"Janssen","sequence":"additional","affiliation":[{"name":"Department of Molecular Microbiology, Ziekenhuis Oost-Limburg, 3600 Genk, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tine","family":"Nelis","sequence":"additional","affiliation":[{"name":"Department of Infection Prevention and Control, Ziekenhuis Oost-Limburg, 3600 Genk, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3088-1649","authenticated-orcid":false,"given":"Ahmed","family":"Elmahy","sequence":"additional","affiliation":[{"name":"Central Data Coordination, Hospital Outbreak Support Team, Ziekenhuis Oost-Limburg, 3600 Genk, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7551-0991","authenticated-orcid":false,"given":"No\u00eblla","family":"Pierlet","sequence":"additional","affiliation":[{"name":"Central Data Coordination, Hospital Outbreak Support Team, Ziekenhuis Oost-Limburg, 3600 Genk, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Els","family":"Oris","sequence":"additional","affiliation":[{"name":"Department of Molecular Microbiology, Ziekenhuis Oost-Limburg, 3600 Genk, 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 of Molecular Microbiology, Ziekenhuis Oost-Limburg, 3600 Genk, Belgium"},{"name":"Faculty of Medicine and Life Sciences\u2014Biomed, University Hasselt, 3500 Hasselt, Belgium"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,12,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"eabd9149","DOI":"10.1126\/science.abd9149","article-title":"Airborne transmission of respiratory viruses","volume":"373","author":"Wang","year":"2021","journal-title":"Science"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"777","DOI":"10.1093\/annweh\/wxaf040","article-title":"The relative effectiveness of personal protective equipment and environmental controls in protecting healthcare workers from COVID-19","volume":"69","author":"Cherrie","year":"2025","journal-title":"Ann. 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