{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,17]],"date-time":"2026-07-17T11:06:57Z","timestamp":1784286417210,"version":"3.55.0"},"reference-count":52,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2024,3,5]],"date-time":"2024-03-05T00:00:00Z","timestamp":1709596800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Public Health"],"abstract":"<jats:sec><jats:title>Introduction<\/jats:title><jats:p>A substantial proportion of the over 700\u2009million COVID-19 cases world-wide experience long-term symptoms. The objectives of this study were to compare symptom trajectories and risk factors for post-COVID-19 condition after Delta and Omicron infection.<\/jats:p><\/jats:sec><jats:sec><jats:title>Methods<\/jats:title><jats:p>This study consecutively recruited patients with SARS-CoV-2 infection from November 2021 to March 2022. We recorded demographics, comorbidities, vaccination status, sick leave, and 18 symptoms during acute infection and after 4\u2009months. The primary outcome measures were symptoms during acute infection and after 4\u2009months. Secondary outcome measures were work and school absenteeism.<\/jats:p><\/jats:sec><jats:sec><jats:title>Results<\/jats:title><jats:p>We followed a cohort of 1,374 non-hospitalized COVID-19 patients in Bergen, Norway, at three time points. The median age was 39.8\u2009years and 11% were children &amp;lt;16\u2009years. Common acute upper respiratory symptoms waned during follow-up. Fatigue remained common from acute infection (40%) until after 4\u2009months (37%). Four months post-infection, patients reported increased frequencies of dyspnea (from 15% during acute illness to 25% at 4\u2009months, <jats:italic>p<\/jats:italic>\u2009&amp;lt;\u20090.001), cognitive symptoms (from 9 to 32%, <jats:italic>p<\/jats:italic>\u2009&amp;lt;\u20090.001) and depression (from 1 to 17%, <jats:italic>p<\/jats:italic>\u2009&amp;lt;\u20090.001). Patients infected with Omicron reported less dyspnea (22% versus 27%, <jats:italic>p<\/jats:italic>\u2009=\u20090.046) and smell\/taste problems (5% versus 19%, <jats:italic>p<\/jats:italic>\u2009&amp;lt;\u20090.001) at 4\u2009months follow-up than those with Delta infection. Comorbidities and female sex were risk factors for persistent dyspnea and cognitive symptoms. Ten percent reported sick leave after acute illness, and vaccination reduced the risk of absenteeism (adjusted risk ratio: 0.36, 95% confidence interval: 0.15, 0.72, <jats:italic>p<\/jats:italic>\u2009=\u20090.008).<\/jats:p><\/jats:sec><jats:sec><jats:title>Conclusion<\/jats:title><jats:p>At 4\u2009months, home-isolated patients infected with Omicron reported overall comparable symptom burden, but less dyspnea and smell\/taste problems than Delta infected patients. Several acute symptoms waned during follow-up. It is worrying that dyspnea, neurocognitive symptoms, and particularly depression, increased significantly during the first 4\u2009months after acute infection. Previous vaccination was protective against prolonged sick leave.<\/jats:p><\/jats:sec>","DOI":"10.3389\/fpubh.2024.1320059","type":"journal-article","created":{"date-parts":[[2024,3,5]],"date-time":"2024-03-05T04:35:29Z","timestamp":1709613329000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":9,"title":["Symptom trajectories of post-COVID sequelae in patients with acute Delta or Omicron infection in Bergen, Norway"],"prefix":"10.3389","volume":"12","author":[{"given":"Arild","family":"Iversen","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bj\u00f8rn","family":"Blomberg","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kjell","family":"Haug","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"B\u00e5rd","family":"Kittang","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"T\u00fcrk\u00fcler","family":"\u00d6zg\u00fcm\u00fcs","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rebecca Jane","family":"Cox","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nina","family":"Langeland","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2024,3,5]]},"reference":[{"key":"ref1","year":"2024"},{"key":"ref2","doi-asserted-by":"publisher","first-page":"747","DOI":"10.1016\/S0140-6736(21)01755-4","article-title":"1-year outcomes in hospital survivors with COVID-19: a longitudinal cohort study","volume":"398","author":"Huang","year":"2021","journal-title":"Lancet"},{"key":"ref3","doi-asserted-by":"publisher","first-page":"e102","DOI":"10.1016\/S1473-3099(21)00703-9","article-title":"Condition WHOCCDWGoP-C-: a clinical case definition of post-COVID-19 condition by a Delphi consensus","volume":"22","author":"Soriano","year":"2022","journal-title":"Lancet Infect Dis"},{"key":"ref4","doi-asserted-by":"publisher","first-page":"7977","DOI":"10.1038\/s41598-022-11929-8","article-title":"Prevalence of post-intensive care syndrome in mechanically ventilated patients with COVID-19","volume":"12","author":"Nanwani-Nanwani","year":"2022","journal-title":"Sci Rep"},{"key":"ref5","doi-asserted-by":"publisher","first-page":"1512","DOI":"10.1164\/rccm.202009-3381OC","article-title":"New physical, mental, and cognitive problems 1 year after ICU admission: a prospective multicenter study","volume":"203","author":"Geense","year":"2021","journal-title":"Am J Respir Crit Care Med"},{"key":"ref6","doi-asserted-by":"publisher","first-page":"1607","DOI":"10.1038\/s41591-021-01433-3","article-title":"Long COVID in a prospective cohort of home-isolated patients","volume":"27","author":"Blomberg","year":"2021","journal-title":"Nat Med"},{"key":"ref7","doi-asserted-by":"publisher","first-page":"e60","DOI":"10.1093\/cid\/ciac655","article-title":"Symptom burden and immune dynamics 6 to 18 months following mild severe acute respiratory syndrome coronavirus 2 infection (SARS-CoV-2): a case-control study","volume":"76","author":"Fjelltveit","year":"2023","journal-title":"Clin Infect Dis"},{"key":"ref8","doi-asserted-by":"publisher","first-page":"e4058","DOI":"10.1093\/cid\/ciaa1792","article-title":"B AS, Gaini S, Strom M, Weihe P: long COVID in the Faroe Islands: a longitudinal study among nonhospitalized patients","volume":"73","author":"Petersen","year":"2021","journal-title":"Clin Infect Dis"},{"key":"ref9","doi-asserted-by":"publisher","first-page":"2347","DOI":"10.1038\/s41591-023-02521-2","article-title":"Postacute sequelae of COVID-19 at 2 years","volume":"29","author":"Bowe","year":"2023","journal-title":"Nat Med"},{"key":"ref10","doi-asserted-by":"publisher","first-page":"815","DOI":"10.1016\/S2215-0366(22)00260-7","article-title":"Neurological and psychiatric risk trajectories after SARS-CoV-2 infection: an analysis of 2-year retrospective cohort studies including 1 284 437 patients","volume":"9","author":"Taquet","year":"2022","journal-title":"Lancet Psychiatry"},{"key":"ref11","doi-asserted-by":"publisher","first-page":"6","DOI":"10.1136\/bmjgh-2021-005427","article-title":"Characterising long COVID: a living systematic review. 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