{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,14]],"date-time":"2026-09-14T20:27:31Z","timestamp":1789417651720,"version":"build-2803163510"},"reference-count":9,"publisher":"American Society for Microbiology","issue":"10","license":[{"start":{"date-parts":[[2025,10,7]],"date-time":"2025-10-07T00:00:00Z","timestamp":1759795200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"},{"start":{"date-parts":[[2025,10,7]],"date-time":"2025-10-07T00:00:00Z","timestamp":1759795200000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/journals.asm.org\/non-commercial-tdm-license"}],"funder":[{"DOI":"10.13039\/501100004587","name":"Instituto de Salud Carlos III","doi-asserted-by":"publisher","award":["2101892"],"award-info":[{"award-number":["2101892"]}],"id":[{"id":"10.13039\/501100004587","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["journals.asm.org"],"crossmark-restriction":true},"short-container-title":["Microbiol Spectr"],"published-print":{"date-parts":[[2025,10,7]]},"abstract":"<jats:title>ABSTRACT<\/jats:title>\n                  <jats:sec>\n                    <jats:title\/>\n                    <jats:p>\n                      Millions of reverse transcription-polymerase chain reaction (RT-PCR) tests have been performed worldwide during the SARS-CoV-2 pandemic, using various protocols. This study evaluates the duration of SARS-CoV-2 RNA detectability by RT-PCR at body temperature and analyzes changes in cycle threshold (Ct) values over time. Positive nasopharyngeal swabs for SARS-CoV-2 RT-PCR (\n                      <jats:italic toggle=\"yes\">n<\/jats:italic>\n                      = 120) with different Ct values were collected from Hospital Universitario 12 de Octubre (Madrid, Spain, 2020). Samples were processed using an open-access protocol for the Hologic Panther Fusion system, targeting the envelope gene. They were stratified into six Ct value groups (&lt;20, 20.0\u201325.0, 25.1\u201330.0, 30.1\u201335.0, 35.1\u201340.0, and &gt;40.0) and incubated at 37\u00b0C for 15, 30, 45, and 60 days, with RT-PCR repeated at each interval. Samples with Ct &lt;20.0 remained positive throughout the study, whereas those with Ct &gt;40.0 were negative by day 15. A significant proportion of samples with Ct \u226435.0 remained positive at day 60. Positivity during incubation decreased with higher Ct values (\n                      <jats:italic toggle=\"yes\">P<\/jats:italic>\n                      &lt; 0.001). Ct values increased over time but inconsistently by day 60. In conclusion, SARS-CoV-2 RNA can persist for months, leading to prolonged RT-PCR positivity. However, repeated RT-PCR testing introduces variability in qualitative results and Ct values, complicating clinical decisions. Patient monitoring should emphasize clinical assessment and viral viability assays rather than repeated RT-PCR testing.\n                    <\/jats:p>\n                    <jats:sec>\n                      <jats:title>IMPORTANCE<\/jats:title>\n                      <jats:p>This study investigates the prolonged persistence of SARS-CoV-2 detected by reverse transcription-PCR (RT-PCR) at human body temperature and the evolution of cycle threshold (Ct) values in positive respiratory samples. Our findings indicate that SARS-CoV-2 RNA can persist for months, and that repeated RT-PCR testing over time introduces variability, particularly in samples with high Ct values. This work highlights the necessity of complementing RT-PCR testing with methods assessing viral viability to avoid over-reliance on repeated testing in clinical decision-making. This study addresses a critical issue in COVID-19 diagnostics, with important implications for clinical management and infection control.<\/jats:p>\n                    <\/jats:sec>\n                  <\/jats:sec>","DOI":"10.1128\/spectrum.01225-25","type":"journal-article","created":{"date-parts":[[2025,9,8]],"date-time":"2025-09-08T13:00:51Z","timestamp":1757336451000},"update-policy":"https:\/\/doi.org\/10.1128\/asmj-crossmark-policy-page","source":"Crossref","is-referenced-by-count":1,"title":["Prolonged SARS-CoV-2 RNA detection by RT-PCR: variability in cycle threshold values over time"],"prefix":"10.1128","volume":"13","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-2882-5250","authenticated-orcid":true,"given":"Irene","family":"Mu\u00f1oz-Gallego","sequence":"first","affiliation":[{"id":[{"id":"https:\/\/ror.org\/00qyh5r35","id-type":"ROR","asserted-by":"publisher"}],"name":"Laboratoy of Virology, Microbiology Department, Hospital Universitario 12 de Octubre","place":["Madrid, Spain"]},{"id":[{"id":"https:\/\/ror.org\/00qyh5r35","id-type":"ROR","asserted-by":"publisher"}],"name":"Biomedical Research Institute imas12, Hospital Universitario 12 de Octubre","place":["Madrid, Spain"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amparo","family":"Rubio","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/00qyh5r35","id-type":"ROR","asserted-by":"publisher"}],"name":"Laboratoy of Virology, Microbiology Department, Hospital Universitario 12 de Octubre","place":["Madrid, Spain"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Miriam","family":"Maseda","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/00qyh5r35","id-type":"ROR","asserted-by":"publisher"}],"name":"Laboratoy of Virology, Microbiology Department, Hospital Universitario 12 de Octubre","place":["Madrid, Spain"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Patricia","family":"Carnicero","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/00qyh5r35","id-type":"ROR","asserted-by":"publisher"}],"name":"Laboratoy of Virology, Microbiology Department, Hospital Universitario 12 de Octubre","place":["Madrid, Spain"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Lola","family":"Folgueira","sequence":"additional","affiliation":[{"id":[{"id":"https:\/\/ror.org\/00qyh5r35","id-type":"ROR","asserted-by":"publisher"}],"name":"Laboratoy of Virology, Microbiology Department, Hospital Universitario 12 de Octubre","place":["Madrid, Spain"]},{"id":[{"id":"https:\/\/ror.org\/00qyh5r35","id-type":"ROR","asserted-by":"publisher"}],"name":"Biomedical Research Institute imas12, Hospital Universitario 12 de Octubre","place":["Madrid, Spain"]},{"id":[{"id":"https:\/\/ror.org\/02p0gd045","id-type":"ROR","asserted-by":"publisher"}],"name":"Department of Medicine, School of Medicine, Universidad Complutense","place":["Madrid, Spain"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"235","reference":[{"key":"e_1_3_3_2_2","doi-asserted-by":"publisher","DOI":"10.1128\/CMR.00028-20"},{"key":"e_1_3_3_3_2","doi-asserted-by":"publisher","DOI":"10.1128\/spectrum.03908-23"},{"key":"e_1_3_3_4_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.jcv.2020.104305"},{"key":"e_1_3_3_5_2","doi-asserted-by":"publisher","DOI":"10.1016\/S0140-6736(21)02346-1"},{"key":"e_1_3_3_6_2","doi-asserted-by":"publisher","DOI":"10.1128\/jcm.00501-22"},{"key":"e_1_3_3_7_2","doi-asserted-by":"publisher","DOI":"10.1016\/S1473-3099(23)00815-0"},{"key":"e_1_3_3_8_2","doi-asserted-by":"publisher","DOI":"10.1016\/j.cll.2022.02.003"},{"key":"e_1_3_3_9_2","doi-asserted-by":"publisher","DOI":"10.1038\/s41598-024-52984-7"},{"key":"e_1_3_3_10_2","doi-asserted-by":"publisher","DOI":"10.1093\/cid\/ciad646"}],"container-title":["Microbiology Spectrum"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/spectrum.01225-25","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/journals.asm.org\/doi\/pdf\/10.1128\/spectrum.01225-25","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,7]],"date-time":"2025-10-07T13:10:07Z","timestamp":1759842607000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.asm.org\/doi\/10.1128\/spectrum.01225-25"}},"subtitle":[],"editor":[{"given":"Alexander","family":"Bello","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2025,10,7]]},"references-count":9,"journal-issue":{"issue":"10","published-print":{"date-parts":[[2025,10,7]]}},"alternative-id":["10.1128\/spectrum.01225-25"],"URL":"https:\/\/doi.org\/10.1128\/spectrum.01225-25","relation":{},"ISSN":["2165-0497"],"issn-type":[{"value":"2165-0497","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,10,7]]},"assertion":[{"value":"2025-04-18","order":0,"name":"received","label":"Received","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-07-28","order":2,"name":"accepted","label":"Accepted","group":{"name":"publication_history","label":"Publication History"}},{"value":"2025-09-08","order":3,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}],"article-number":"e01225-25"}}