{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,27]],"date-time":"2026-02-27T17:17:27Z","timestamp":1772212647605,"version":"3.50.1"},"reference-count":38,"publisher":"Public Library of Science (PLoS)","issue":"11","license":[{"start":{"date-parts":[[2021,11,22]],"date-time":"2021-11-22T00:00:00Z","timestamp":1637539200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"M\u00fcnch Foundation"}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:p>Pandemic scenarios like SARS-Cov-2 require rapid information aggregation. In the age of eHealth and data-driven medicine, publicly available symptom tracking tools offer efficient and scalable means of collecting and analyzing large amounts of data. As a result, information gains can be communicated to front-line providers. We have developed such an application in less than a month and reached more than 500 thousand users within 48 hours. The dataset contains information on basic epidemiological parameters, symptoms, risk factors and details on previous exposure to a COVID-19 patient. Exploratory Data Analysis revealed different symptoms reported by users with confirmed contacts vs. no confirmed contacts. The symptom combination of anosmia, cough and fatigue was the most important feature to differentiate the groups, while single symptoms such as anosmia, cough or fatigue alone were not sufficient. A linear regression model from the literature using the same symptom combination as features was applied on all data. Predictions matched the regional distribution of confirmed cases closely across Germany, while also indicating that the number of cases in northern federal states might be higher than officially reported. In conclusion, we report that symptom combinations anosmia, fatigue and cough are most likely to indicate an acute SARS-CoV-2 infection.<\/jats:p>","DOI":"10.1371\/journal.pone.0258649","type":"journal-article","created":{"date-parts":[[2021,11,22]],"date-time":"2021-11-22T13:24:22Z","timestamp":1637587462000},"page":"e0258649","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":1,"title":["Towards a COVID-19 symptom triad: The importance of symptom constellations in the SARS-CoV-2 pandemic"],"prefix":"10.1371","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-6368-197X","authenticated-orcid":true,"given":"Leander","family":"Melms","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Evelyn","family":"Falk","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Bernhard","family":"Schieffer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Andreas","family":"Jerrentrup","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Uwe","family":"Wagner","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sami","family":"Matrood","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8320-3206","authenticated-orcid":true,"given":"J\u00fcrgen R.","family":"Schaefer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Tobias","family":"M\u00fcller","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Martin","family":"Hirsch","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2021,11,22]]},"reference":[{"key":"pone.0258649.ref001","doi-asserted-by":"crossref","first-page":"270","DOI":"10.1038\/s41586-020-2012-7","article-title":"A pneumonia outbreak associated with a new coronavirus of probable bat origin","volume":"579","author":"P Zhou","year":"2020","journal-title":"Nature"},{"key":"pone.0258649.ref002","unstructured":"Coronavirus Disease (COVID-19) Situation Reports. [cited 17 Aug 2020]. Available: https:\/\/www.who.int\/emergencies\/diseases\/novel-coronavirus-2019\/situation-reports"},{"key":"pone.0258649.ref003","unstructured":"Besprechung der Bundeskanzlerin mit den Regierungschefinnen und Regierungschefs der L\u00e4nder. In: Startseite [Internet]. [cited 17 Aug 2020]. Available: https:\/\/www.bundesregierung.de\/breg-de\/themen\/coronavirus\/besprechung-der-bundeskanzlerin-mit-den-regierungschefinnen-und-regierungschefs-der-laender-1733248"},{"key":"pone.0258649.ref004","doi-asserted-by":"crossref","first-page":"e201","DOI":"10.1016\/S2589-7500(20)30026-1","article-title":"Early epidemiological analysis of the coronavirus disease 2019 outbreak based on crowdsourced data: a population-level observational study","volume":"2","author":"K Sun","year":"2020","journal-title":"Lancet Digit Health."},{"key":"pone.0258649.ref005","doi-asserted-by":"crossref","first-page":"3102","DOI":"10.1038\/s41467-019-11067-2","article-title":"Using \u201coutbreak science\u201d to strengthen the use of models during epidemics","volume":"10","author":"C Rivers","year":"2019","journal-title":"Nat Commun"},{"key":"pone.0258649.ref006","doi-asserted-by":"crossref","first-page":"3822","DOI":"10.1021\/acsnano.0c02624","article-title":"Diagnosing COVID-19: The Disease and Tools for Detection.","volume":"14","author":"B Udugama","year":"2020","journal-title":"ACS Nano."},{"key":"pone.0258649.ref007","doi-asserted-by":"crossref","first-page":"e66","DOI":"10.2196\/publichealth.7429","article-title":"Influenzanet: Citizens Among 10 Countries Collaborating to Monitor Influenza in Europe","volume":"3","author":"CE Koppeschaar","year":"2017","journal-title":"JMIR Public Health Surveill."},{"key":"pone.0258649.ref008","doi-asserted-by":"crossref","first-page":"S386","DOI":"10.1093\/infdis\/jiw280","article-title":"Participatory Syndromic Surveillance of Influenza in Europe","volume":"214","author":"C Guerrisi","year":"2016","journal-title":"J Infect Dis"},{"key":"pone.0258649.ref009","doi-asserted-by":"crossref","first-page":"2124","DOI":"10.2105\/AJPH.2015.302696","article-title":"Flu Near You: Crowdsourced Symptom Reporting Spanning 2 Influenza Seasons","volume":"105","author":"MS Smolinski","year":"2015","journal-title":"Am J Public Health"},{"key":"pone.0258649.ref010","doi-asserted-by":"crossref","first-page":"316","DOI":"10.1007\/s11908-013-0341-5","article-title":"Why We Need Crowdsourced Data in Infectious Disease Surveillance","volume":"15","author":"R Chunara","year":"2013","journal-title":"Curr Infect Dis Rep"},{"key":"pone.0258649.ref011","doi-asserted-by":"crossref","first-page":"2153","DOI":"10.1056\/NEJMp0900702","article-title":"Digital Disease Detection\u2014Harnessing the Web for Public Health Surveillance","volume":"360","author":"JS Brownstein","year":"2009","journal-title":"N Engl J Med"},{"key":"pone.0258649.ref012","unstructured":"COVID-19 Tracking Schweiz. [cited 9 Oct 2020]. Available: https:\/\/www.covidtracker.ch\/"},{"key":"pone.0258649.ref013","unstructured":"Coronavirus Comunidad de Madrid. In: Coronavirus Comunidad de Madrid [Internet]. [cited 9 Oct 2020]. Available: https:\/\/coronavirus.comunidad.madrid\/"},{"key":"pone.0258649.ref014","unstructured":"MaladieCoronavirus.fr. [cited 21 Aug 2020]. Available: https:\/\/www.maladiecoronavirus.fr"},{"key":"pone.0258649.ref015","unstructured":"COVID Symptom Study\u2014Help slow the spread of COVID-19. [cited 9 Oct 2020]. Available: https:\/\/covid.joinzoe.com"},{"key":"pone.0258649.ref016","doi-asserted-by":"crossref","first-page":"497","DOI":"10.1016\/S0140-6736(20)30183-5","article-title":"Clinical features of patients infected with 2019 novel coronavirus in Wuhan, China.","volume":"395","author":"C Huang","year":"2020","journal-title":"Lancet Lond Engl."},{"key":"pone.0258649.ref017","doi-asserted-by":"crossref","first-page":"470","DOI":"10.1016\/S0140-6736(20)30185-9","article-title":"A novel coronavirus outbreak of global health concern","volume":"395","author":"C Wang","year":"2020","journal-title":"Lancet Lond Engl."},{"key":"pone.0258649.ref018","doi-asserted-by":"crossref","first-page":"507","DOI":"10.1016\/S0140-6736(20)30211-7","article-title":"Epidemiological and clinical characteristics of 99 cases of 2019 novel coronavirus pneumonia in Wuhan, China: a descriptive study","volume":"395","author":"N Chen","year":"2020","journal-title":"Lancet Lond Engl."},{"key":"pone.0258649.ref019","article-title":"Clinical Characteristics of Coronavirus Disease 2019 in China","author":"W Guan","year":"2020","journal-title":"N Engl J Med"},{"key":"pone.0258649.ref020","article-title":"Clinical characteristics of hospitalized patients with SARS\u2010CoV\u20102 infection: A single arm meta\u2010analysis","author":"P Sun","year":"2020","journal-title":"J Med Virol"},{"key":"pone.0258649.ref021","doi-asserted-by":"crossref","first-page":"842","DOI":"10.1016\/j.cmi.2020.04.023","article-title":"COVID-19 pandemic\u2014a focused review for clinicians","volume":"26","author":"M Cevik","year":"2020","journal-title":"Clin Microbiol Infect"},{"key":"pone.0258649.ref022","doi-asserted-by":"crossref","first-page":"1054","DOI":"10.1016\/S0140-6736(20)30566-3","article-title":"Clinical course and risk factors for mortality of adult inpatients with COVID-19 in Wuhan, China: a retrospective cohort study","volume":"395","author":"F Zhou","year":"2020","journal-title":"The Lancet"},{"key":"pone.0258649.ref023","doi-asserted-by":"crossref","first-page":"1730","DOI":"10.1111\/all.14238","article-title":"Clinical characteristics of 140 patients infected with SARS-CoV-2 in Wuhan","volume":"75","author":"J Zhang","year":"2020","journal-title":"China. Allergy."},{"key":"pone.0258649.ref024","doi-asserted-by":"crossref","first-page":"1037","DOI":"10.1038\/s41591-020-0916-2","article-title":"Real-time tracking of self-reported symptoms to predict potential COVID-19","volume":"26","author":"C Menni","year":"2020","journal-title":"Nat Med"},{"key":"pone.0258649.ref025","doi-asserted-by":"crossref","first-page":"354","DOI":"10.1002\/lio2.384","article-title":"Sinonasal pathophysiology of SARS-CoV-2 and COVID-19: A systematic review of the current evidence","volume":"5","author":"I Gengler","year":"2020","journal-title":"Laryngoscope Investig Otolaryngol."},{"key":"pone.0258649.ref026","article-title":"New loss of smell and taste: Uncommon symptoms in COVID-19 patients on Nord Franche-Comte cluster, France","author":"T Klopfenstein","year":"2020","journal-title":"Int J Infect Dis"},{"key":"pone.0258649.ref027","doi-asserted-by":"crossref","first-page":"1017","DOI":"10.1038\/s41591-020-0968-3","article-title":"Extrapulmonary manifestations of COVID-19","volume":"26","author":"A Gupta","year":"2020","journal-title":"Nat Med"},{"key":"pone.0258649.ref028","doi-asserted-by":"crossref","first-page":"e19855","DOI":"10.2196\/19855","article-title":"Epidemiological Observations on the Association Between Anosmia and COVID-19 Infection: Analysis of Data From a Self-Assessment Web Application","volume":"22","author":"F Denis","year":"2020","journal-title":"J Med Internet Res"},{"key":"pone.0258649.ref029","doi-asserted-by":"crossref","first-page":"102581","DOI":"10.1016\/j.amjoto.2020.102581","article-title":"COVID-19 and anosmia: A review based on up-to-date knowledge.","volume":"41","author":"X Meng","year":"2020","journal-title":"Am J Otolaryngol."},{"key":"pone.0258649.ref030","doi-asserted-by":"crossref","first-page":"2089","DOI":"10.1001\/jama.2020.6771","article-title":"Alterations in Smell or Taste in Mildly Symptomatic Outpatients With SARS-CoV-2 Infection.","volume":"323","author":"G Spinato","year":"2020","journal-title":"JAMA."},{"key":"pone.0258649.ref031","unstructured":"Robert Koch-Institut. COVID-19 Verdacht: Testkriterien und Ma\u00dfnahmen Orientierungshilfe f\u00fcr \u00c4rztinnen und \u00c4rzte. [cited 19 Aug 2020]. Available: https:\/\/www.rki.de\/DE\/Content\/InfAZ\/N\/Neuartiges_Coronavirus\/Massnahmen_Verdachtsfall_Infografik_DINA3.pdf?__blob=publicationFile"},{"key":"pone.0258649.ref032","unstructured":"ENT UK at The Royal College of Surgeons of England. Loss of sense of smell as marker of COVID-19 infection. In: entuk.org [Internet]. [cited 19 Aug 2020]. Available: https:\/\/www.entuk.org\/sites\/default\/files\/files\/Loss%20of%20sense%20of%20smell%20as%20marker%20of%20COVID.pdf"},{"key":"pone.0258649.ref033","article-title":"COVID-19 Anosmia Reporting Tool","author":"AAO-HNS","year":"2020","journal-title":"American Academy of Otolaryngology-Head and Neck Surgery"},{"key":"pone.0258649.ref034","doi-asserted-by":"crossref","first-page":"5218","DOI":"10.3390\/ijerph17145218","article-title":"Symptoms in Health Care Workers during the COVID-19 Epidemic","volume":"17","author":"N Magnavita","year":"2020","journal-title":"A Cross-Sectional Survey. Int J Environ Res Public Health."},{"key":"pone.0258649.ref035","article-title":"Strong associations and moderate predictive value of early symptoms for SARS-CoV-2 test positivity among healthcare workers, the Netherlands, March 2020.","volume":"25","author":"A Tostmann","year":"2020","journal-title":"Euro Surveill Bull Eur Sur Mal Transm Eur Commun Dis Bull."},{"key":"pone.0258649.ref036","doi-asserted-by":"crossref","first-page":"1362","DOI":"10.1126\/science.abc0473","article-title":"Rapid implementation of mobile technology for real-time epidemiology of COVID-19","volume":"368","author":"DA Drew","year":"2020","journal-title":"Science"},{"key":"pone.0258649.ref037","doi-asserted-by":"crossref","DOI":"10.15585\/mmwr.mm6930e1","article-title":"Symptom Duration and Risk Factors for Delayed Return to Usual Health Among Outpatients with COVID-19 in a Multistate Health Care Systems Network\u2014United States, March\u2013June 2020","volume":"69","author":"MW Tenforde","year":"2020","journal-title":"MMWR Morb Mortal Wkly Rep"},{"key":"pone.0258649.ref038","doi-asserted-by":"crossref","first-page":"2000180","DOI":"10.2807\/1560-7917.ES.2020.25.10.2000180","article-title":"Estimating the asymptomatic proportion of coronavirus disease 2019 (COVID-19) cases on board the Diamond Princess cruise ship, Yokohama, Japan, 2020","volume":"25","author":"K Mizumoto","year":"2020","journal-title":"Eurosurveillance."}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0258649","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,22]],"date-time":"2021-11-22T13:24:47Z","timestamp":1637587487000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0258649"}},"subtitle":[],"editor":[{"given":"Siew Ann","family":"Cheong","sequence":"first","affiliation":[],"role":[{"role":"editor","vocabulary":"crossref"}]}],"short-title":[],"issued":{"date-parts":[[2021,11,22]]},"references-count":38,"journal-issue":{"issue":"11","published-online":{"date-parts":[[2021,11,22]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0258649","relation":{"has-preprint":[{"id-type":"doi","id":"10.1101\/2021.02.01.21250537","asserted-by":"object"}]},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,11,22]]}}}