{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,10,1]],"date-time":"2025-10-01T15:35:21Z","timestamp":1759332921205,"version":"build-2065373602"},"reference-count":14,"publisher":"Public Library of Science (PLoS)","issue":"9","license":[{"start":{"date-parts":[[2025,9,30]],"date-time":"2025-09-30T00:00:00Z","timestamp":1759190400000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Anonymous"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS One"],"abstract":"<jats:sec id=\"sec001\">\n<jats:title>Objective<\/jats:title>\n<jats:p>The objective of this study was to identify demographic and clinical factors associated with SARS-CoV-2 infection among household contacts (HCs) following exposure to a confirmed case.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec002\">\n<jats:title>Methods<\/jats:title>\n<jats:p>We analyzed an existing case-ascertained prospective cohort study of 43 HCs of SARS-CoV-2-positive index cases recruited from Stanford Health Care between March 2020 and June 2022. Participants self-collected nasal swabs daily for up to 21 days for reverse transcription polymerase chain reaction (RT-PCR) testing and reported symptoms in daily diaries. Using Cox proportional hazards models, we assessed associations between participant characteristics over time to first positive PCR result.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec003\">\n<jats:title>Results<\/jats:title>\n<jats:p>We found that symptomatology and race\/ethnicity were independently associated with increased infection risk. In multivariable analysis, participants with systemic symptoms had a higher likelihood of testing positive (adjusted hazard ratio [aHR]=2.62; 95% confidence interval [CI]: 1.38\u20136.55). Additionally, identifying as a racial\/ethnic minority had a greater risk of a positive test (aHR\u2009=\u20092.55 for systemic symptoms, 2.43 for any respiratory symptoms, and 2.40 for upper respiratory symptoms) compared to white patients.<\/jats:p>\n<\/jats:sec>\n<jats:sec id=\"sec004\">\n<jats:title>Conclusion<\/jats:title>\n<jats:p>These findings underscore the importance of symptom-based surveillance and highlight ongoing racial and ethnic disparities in SARS-CoV-2 transmission risk. This study also demonstrates the feasibility of longitudinal, self-administered testing and offers a scalable model for investigating transmission dynamics of respiratory viruses in community settings.<\/jats:p>\n<\/jats:sec>","DOI":"10.1371\/journal.pone.0332819","type":"journal-article","created":{"date-parts":[[2025,9,30]],"date-time":"2025-09-30T17:35:12Z","timestamp":1759253712000},"page":"e0332819","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":0,"title":["Associations of SARS-CoV-2 PCR positivity with clinical symptoms and race\/ethnicity: The household transmission study"],"prefix":"10.1371","volume":"20","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-0425-9688","authenticated-orcid":true,"given":"Sara H.","family":"Goodman","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jonathan","family":"Altamirano","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4154-2802","authenticated-orcid":true,"given":"Julianne","family":"Burns","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8700-8926","authenticated-orcid":true,"given":"Clea S.","family":"Sarnquist","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jennifer S.","family":"Read","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yvonne","family":"Maldonado","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2025,9,30]]},"reference":[{"issue":"4","key":"pone.0332819.ref001","doi-asserted-by":"crossref","DOI":"10.1001\/jamanetworkopen.2022.9317","article-title":"Household secondary attack rates of SARS-CoV-2 by variant and vaccination status: an updated systematic review and meta-analysis","volume":"5","author":"ZJ Madewell","year":"2022","journal-title":"JAMA Netw Open"},{"issue":"10","key":"pone.0332819.ref002","doi-asserted-by":"crossref","first-page":"1776","DOI":"10.1093\/cid\/ciab701","article-title":"Household transmission of severe acute respiratory syndrome coronavirus 2 in the United States: living density, viral load, and disproportionate impact on communities of color","volume":"74","author":"C Cerami","year":"2022","journal-title":"Clin Infect Dis"},{"key":"pone.0332819.ref003","doi-asserted-by":"crossref","first-page":"104383","DOI":"10.1016\/j.jcv.2020.104383","article-title":"Comparison of the Panther Fusion and a laboratory-developed test targeting the envelope gene for detection of SARS-CoV-2","volume":"127","author":"CA Hogan","year":"2020","journal-title":"J Clin Virol"},{"issue":"7","key":"pone.0332819.ref004","doi-asserted-by":"crossref","DOI":"10.1371\/journal.pone.0305300","article-title":"Natural history of shedding and household transmission of severe acute respiratory syndrome coronavirus 2 using intensive high-resolution sampling","volume":"19","author":"J Altamirano","year":"2024","journal-title":"PLoS One"},{"key":"pone.0332819.ref005","unstructured":"United States Food and Drug Administration. Emergency Use Authorization (EUA) Summary SARS-CoV-2 RT-PCR Assay Stanford Health Care Clinical Virology Laboratory. Greenbelt, MD. 2020. Available from: https:\/\/www.fda.gov\/media\/136818\/download"},{"issue":"1","key":"pone.0332819.ref006","doi-asserted-by":"crossref","first-page":"8738","DOI":"10.1038\/s41598-021-88308-2","article-title":"Racial disparities in COVID-19 outcomes exist despite comparable Elixhauser comorbidity indices between Blacks, Hispanics, Native Americans, and Whites","volume":"11","author":"F Qeadan","year":"2021","journal-title":"Sci Rep"},{"issue":"1","key":"pone.0332819.ref007","doi-asserted-by":"crossref","first-page":"20","DOI":"10.1089\/pop.2020.0163","article-title":"Disparities in SARS-CoV-2 positivity rates: associations with race and ethnicity","volume":"24","author":"HW Kaufman","year":"2021","journal-title":"Popul Health Manag"},{"key":"pone.0332819.ref008","doi-asserted-by":"crossref","first-page":"101019","DOI":"10.1016\/j.eclinm.2021.101019","article-title":"Characterizing long COVID in an international cohort: 7 months of symptoms and their impact","volume":"38","author":"HE Davis","year":"2021","journal-title":"EClinicalMedicine"},{"issue":"1","key":"pone.0332819.ref009","doi-asserted-by":"crossref","first-page":"49","DOI":"10.1007\/s11606-021-06738-0","article-title":"Racial\/ethnic differences in emergency department utilization and experience","volume":"37","author":"L Parast","year":"2022","journal-title":"J Gen Intern Med"},{"issue":"2","key":"pone.0332819.ref010","doi-asserted-by":"crossref","first-page":"149","DOI":"10.1016\/j.jemermed.2006.05.042","article-title":"The emergency department for routine healthcare: race\/ethnicity, socioeconomic status, and perceptual factors","volume":"32","author":"R Hong","year":"2007","journal-title":"J Emerg Med"},{"issue":"10","key":"pone.0332819.ref011","doi-asserted-by":"crossref","DOI":"10.1001\/jamapediatrics.2021.2025","article-title":"Comparison of symptoms and RNA levels in children and adults with SARS-CoV-2 infection in the community setting","volume":"175","author":"E Chung","year":"2021","journal-title":"JAMA Pediatr"},{"issue":"2","key":"pone.0332819.ref012","doi-asserted-by":"crossref","first-page":"301","DOI":"10.1093\/cid\/ciad582","article-title":"The new normal: delayed peak SARS-CoV-2 viral loads relative to symptom onset and implications for COVID-19 testing programs","volume":"78","author":"JK Frediani","year":"2024","journal-title":"Clin Infect Dis"},{"issue":"5","key":"pone.0332819.ref013","doi-asserted-by":"crossref","first-page":"857","DOI":"10.1016\/0029-7844(95)00251-L","article-title":"The problem of the type II statistical error","volume":"86","author":"R Mittendorf","year":"1995","journal-title":"Obstet Gynecol"},{"issue":"3","key":"pone.0332819.ref014","doi-asserted-by":"crossref","first-page":"749","DOI":"10.1007\/s40121-023-00772-7","article-title":"Systematic review on the correlation between SARS-CoV-2 real-time PCR cycle threshold values and epidemiological trends","volume":"12","author":"E Sala","year":"2023","journal-title":"Infect Dis Ther"}],"container-title":["PLOS One"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0332819","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,9,30]],"date-time":"2025-09-30T17:35:14Z","timestamp":1759253714000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0332819"}},"subtitle":[],"editor":[{"given":"Sarah","family":"Nanzigu","sequence":"first","affiliation":[],"role":[{"role":"editor","vocabulary":"crossref"}]}],"short-title":[],"issued":{"date-parts":[[2025,9,30]]},"references-count":14,"journal-issue":{"issue":"9","published-online":{"date-parts":[[2025,9,30]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0332819","relation":{},"ISSN":["1932-6203"],"issn-type":[{"type":"electronic","value":"1932-6203"}],"subject":[],"published":{"date-parts":[[2025,9,30]]}}}