{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,8]],"date-time":"2026-04-08T15:49:47Z","timestamp":1775663387403,"version":"3.50.1"},"reference-count":24,"publisher":"American Medical Association (AMA)","issue":"4","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["JAMA Netw Open"],"abstract":"\n Importance<\/jats:title>\n Early detection of SARS-CoV-2 may mitigate nosocomial spread, yet universal screening of asymptomatic patients remains debated.<\/jats:p>\n <\/jats:sec>\n \n Objective<\/jats:title>\n To evaluate the diagnostic yield of systematic SARS-CoV-2 screening in correlation with community incidence and wastewater viral load and assess clinical outcomes among inpatients with false-positive results.<\/jats:p>\n <\/jats:sec>\n \n Design, Setting, and Participants<\/jats:title>\n This retrospective quality-control cohort study assessed the results of systematic SARS-CoV-2 screening of asymptomatic patients at the University Hospital Basel in Basel, Switzerland, a tertiary care center admitting more than 40\u202f000 adult patients annually. All patients with systematic screenings for SARS-CoV-2 infection from February 8, 2021, to July 5, 2021, and from August 25, 2021, to December 5, 2022, were included. Data were analyzed from January 2024 to February 2025.<\/jats:p>\n <\/jats:sec>\n \n Exposure<\/jats:title>\n Saliva-based PCR-tests to screen for asymptomatic SARS-CoV-2 infection on admission and at regular 3- to 5-day intervals during hospitalization.<\/jats:p>\n <\/jats:sec>\n \n Main Outcomes and Measures<\/jats:title>\n The primary end points were the proportion of positive and false-positive SARS-CoV-2 test results, as well as the number needed to screen to find 1 otherwise undetected SARS-CoV-2 infection. Clinical data and test results were analyzed along with community incidence and wastewater viral loads. Correlations were calculated using Spearman test, and clinical implications of false-positive results were assessed.<\/jats:p>\n <\/jats:sec>\n \n Results<\/jats:title>\n Among 75\u202f667 screening tests performed on 42\u202f666 patients (21\u202f591 [50.6%] female; median [IQR] age, 64 [45-76] years), 761 patients (1.2% of tests) had positive results. These were classified as true-positive results in 483 patients (63.5%) and false-positive results in 278 patients (36.5%). Among patients with false-positive test results, 139 patients (50.0%) experienced unnecessary isolation, 46 patients (16.5%) were exposed to patients with true-positive SARS-CoV-2 test results by cohorting, and 9 patients (3.2%) received delayed interventions. Screening test positivity correlated with local incidence of SARS-CoV-2 infections and wastewater viral loads. A total of 93.7% of positive test results were recorded during weeks with high community incidence (ie, &amp;gt;150 events per 100\u202f000 inhabitants), in which the proportion of patients with false-positive test results was lower (249 of 709 patients [35.1%]) compared with weeks with low community incidence (ie, &amp;lt;150 events 100\u202f000 inhabitants), with 29 of 52 patients (55.8%) having false-positive results.<\/jats:p>\n <\/jats:sec>\n \n Conclusions and Relevance<\/jats:title>\n In this cohort study, universal SARS-CoV-2 screening detected asymptomatic carriers of SARS-CoV-2 infection, aligned with community incidence, and thus may support infection prevention and control measures. However, the unintended clinical outcomes, particularly during times of low incidence, necessitate careful contextual implementation.<\/jats:p>\n <\/jats:sec>","DOI":"10.1001\/jamanetworkopen.2026.5867","type":"journal-article","created":{"date-parts":[[2026,4,8]],"date-time":"2026-04-08T15:00:29Z","timestamp":1775660429000},"page":"e265867","source":"Crossref","is-referenced-by-count":0,"title":["Diagnostic Value and Outcomes of Systematic SARS-CoV-2 Screening in Asymptomatic Patients"],"prefix":"10.1001","volume":"9","author":[{"given":"Marvin","family":"Weiss","sequence":"first","affiliation":[{"name":"Division of Infectious Diseases, University Hospital Basel & University of Basel, Basel, Switzerland"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Pascal","family":"Urwyler","sequence":"additional","affiliation":[{"name":"Division of Infectious Diseases, University Hospital Basel & University of Basel, Basel, 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