{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,27]],"date-time":"2026-04-27T19:25:13Z","timestamp":1777317913223,"version":"3.51.4"},"reference-count":28,"publisher":"Public Library of Science (PLoS)","issue":"5","license":[{"start":{"date-parts":[[2021,5,18]],"date-time":"2021-05-18T00:00:00Z","timestamp":1621296000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100004829","name":"Department of Science and Technology of Sichuan Province","doi-asserted-by":"publisher","award":["2019JDKP0056"],"award-info":[{"award-number":["2019JDKP0056"]}],"id":[{"id":"10.13039\/501100004829","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100004829","name":"Department of Science and Technology of Sichuan Province","doi-asserted-by":"publisher","award":["2020YFS0127"],"award-info":[{"award-number":["2020YFS0127"]}],"id":[{"id":"10.13039\/501100004829","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100019014","name":"Chengdu Science and Technology project","doi-asserted-by":"crossref","award":["2020-YF05-00306-SN"],"award-info":[{"award-number":["2020-YF05-00306-SN"]}],"id":[{"id":"10.13039\/501100019014","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:p>Coronavirus disease 2019 (COVID-19) is highly contagious and has affected the whole world. We seek to investigate the clinical and laboratory characteristics of COVID-19 patients in the high altitude areas of Sichuan, China. In this retrospective cohort study, a total of 67 patients with laboratory-confirmed SARS-CoV-2 infections in Sichuan\u2019s Ngawa Tibetan and Qiang Autonomous Prefecture were included from February 1, 2020, to March 2, 2020. Their clinical characteristics, as well as radiological and laboratory features, were extracted. Four (6.0%) patients were categorized as severe cases; 39 (58.2%) were non-severe cases, and 24 (35.8%) were asymptomatic cases. A total of 46 (68.7%) patients were associated with cluster infection events in this study. The most common symptoms were cough, sputum production, dyspnea, fatigue or myalgia, and headache. Seven (10.4%) patients showed leucopenia, and 20 (29.9%) patients showed lymphopenia. Lymphocyte counts and neutrophil-to-lymphocyte ratios (NPR) were different between the three groups. In total, 14 (20.9%) patients had thrombocytopenia, and prothrombin times (PT) and fibrinogen levels differed between groups. We also found significant differences in sodium, chloride and calcium levels between the three groups. Antiviral therapy did not lead to obvious adverse events or shortened durations from initial positive to subsequent negative nuclei acid tests. Advanced age, hypertension, high neutrophil count, the neutrophil-to-lymphocyte ratio, fibrinogen and lactate dehydrogenase levels were identified as independent risk factors for symptomatic cases of COVID-19. In conclusion, the symptoms of patients in high altitude areas were mild, and about one third were asymptomatic. We also identified several independent risk factors for symptomatic cases of COVID-19.<\/jats:p>","DOI":"10.1371\/journal.pone.0249964","type":"journal-article","created":{"date-parts":[[2021,5,18]],"date-time":"2021-05-18T17:41:37Z","timestamp":1621359697000},"page":"e0249964","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":8,"title":["Clinical characteristics and laboratory features of COVID-19 in high altitude areas: A retrospective cohort study"],"prefix":"10.1371","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-8240-7047","authenticated-orcid":true,"given":"Hanxiao","family":"Chen","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Lang","family":"Qin","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Sixian","family":"Wu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Wenming","family":"Xu","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-1745-9283","authenticated-orcid":true,"given":"Rui","family":"Gao","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaohong","family":"Zhang","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"340","published-online":{"date-parts":[[2021,5,18]]},"reference":[{"issue":"10223","key":"pone.0249964.ref001","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":"The Lancet."},{"key":"pone.0249964.ref002","unstructured":"Organization WH. Report of the WHO-China Joint Mission on Coronavirus Disease 2019 (COVID-19) https:\/\/www.who.int\/docs\/default-source\/coronaviruse\/who-china-joint-mission-on-covid-19-final-report.pdf2020, February 24 [cited 2020 2 March]. Available from: https:\/\/www.who.int\/docs\/default-source\/coronaviruse\/who-china-joint-mission-on-covid-19-final-report.pdf."},{"key":"pone.0249964.ref003","unstructured":"Organization WH. Rolling updates on coronavirus disease (COVID-19) https:\/\/www.who.int\/emergencies\/diseases\/novel-coronavirus-2019\/events-as-they-happen2020 March 3 [cited 2020 3 March]. 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Clinical management of severe acute respiratory infection when novel coronavirus (nCoV) infection is suspected: Interim guidance https:\/\/www.who.int\/publications-detail\/clinical-management-of-severe-acute-respiratory-infection-when-novel-coronavirus-(ncov)-infection-is-suspected2020 28 January [cited 2020 1 March]. Available from: https:\/\/www.who.int\/publications-detail\/clinical-management-of-severe-acute-respiratory-infection-when-novel-coronavirus-(ncov)-infection-is-suspected."},{"key":"pone.0249964.ref013","unstructured":"China NHCotPsRo. Diagnosis and treatment of novel coronavirus pneumonia (trial version sixth) http:\/\/www.gov.cn\/zhengce\/zhengceku\/2020-02\/19\/content_5480948.htm2020 [cited 2020 20 February]. Available from: http:\/\/www.gov.cn\/zhengce\/zhengceku\/2020-02\/19\/content_5480948.htm."},{"key":"pone.0249964.ref014","unstructured":"China NHCotPsRo. 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Available from: http:\/\/www.gov.cn\/zhengce\/zhengceku\/2020-02\/05\/content_5474791.htm."},{"key":"pone.0249964.ref015","article-title":"A descriptive study of the impact of diseases control and prevention on the epidemics dynamics and clinical features of SARS-CoV-2 outbreak in Shanghai, lessons learned for metropolis epidemics prevention","author":"H Lu","journal-title":"medRxiv"},{"key":"pone.0249964.ref016","article-title":"Clinical characteristics of 24 asymptomatic infections with COVID-19 screened among close contacts in Nanjing, China.","author":"Z Hu","year":"2020","journal-title":"Science China Life sciences"},{"issue":"6","key":"pone.0249964.ref017","doi-asserted-by":"crossref","first-page":"656","DOI":"10.1016\/j.jinf.2020.03.041","article-title":"Clinical characteristics of coronavirus disease 2019 (COVID-19) in China: A systematic review and meta-analysis","volume":"80","author":"L Fu","year":"2020","journal-title":"J Infect."},{"key":"pone.0249964.ref018","doi-asserted-by":"crossref","first-page":"108463","DOI":"10.1016\/j.diabres.2020.108463","article-title":"Incidence of COVID-19 infection and prevalence of diabetes, obesity and hypertension according to altitude in Peruvian population","volume":"169","author":"SN Secl\u00e9n","year":"2020","journal-title":"Diabetes Res Clin Pract"},{"key":"pone.0249964.ref019","first-page":"200370","article-title":"Time Course of Lung Changes On Chest CT During Recovery From 2019 Novel Coronavirus (COVID-19) Pneumonia.","volume":"2020","author":"F Pan","journal-title":"Radiology"},{"issue":"7","key":"pone.0249964.ref020","doi-asserted-by":"crossref","first-page":"474","DOI":"10.1093\/qjmed\/hcaa089","article-title":"Epidemiologic and clinical characteristics of 91 hospitalized patients with COVID-19 in Zhejiang, China: a retrospective, multi-centre case series","volume":"113","author":"GQ Qian","year":"2020","journal-title":"Qjm"},{"key":"pone.0249964.ref021","article-title":"The stimulation of thrombosis by hypoxia","author":"N Gupta","year":"2019","journal-title":"Thrombosis research"},{"key":"pone.0249964.ref022","article-title":"Clinical and immunological features of severe and moderate coronavirus disease 2019","author":"G Chen","year":"2020","journal-title":"The Journal of clinical investigation."},{"key":"pone.0249964.ref023","article-title":"Dysregulation of Immune Response in Patients with COVID-19 in Wuhan, China","author":"C Qin","year":"2020","journal-title":"China (February 17, 2020)."},{"issue":"1","key":"pone.0249964.ref024","doi-asserted-by":"crossref","first-page":"206","DOI":"10.1186\/s12967-020-02374-0","article-title":"Neutrophil-to-lymphocyte ratio predicts critical illness patients with 2019 coronavirus disease in the early stage","volume":"18","author":"J Liu","year":"2020","journal-title":"J Transl Med."},{"issue":"10229","key":"pone.0249964.ref025","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.0249964.ref026","doi-asserted-by":"crossref","first-page":"557453","DOI":"10.3389\/fmed.2020.557453","article-title":"Prognostic Factors for COVID-19 Pneumonia Progression to Severe Symptoms Based on Earlier Clinical Features: A Retrospective Analysis","volume":"7","author":"H Huang","year":"2020","journal-title":"Front Med (Lausanne)."},{"key":"pone.0249964.ref027","article-title":"Clinical Characteristics of 138 Hospitalized Patients With 2019 Novel Coronavirus\u2013Infected Pneumonia in Wuhan, China.","author":"D Wang","year":"2020","journal-title":"JAMA"},{"issue":"1","key":"pone.0249964.ref028","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/j.virol.2013.06.018","article-title":"Oxygen tension level and human viral infections","volume":"444","author":"F Morinet","year":"2013","journal-title":"Virology"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0249964","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,5,18]],"date-time":"2021-05-18T17:42:06Z","timestamp":1621359726000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0249964"}},"subtitle":[],"editor":[{"given":"Raffaele","family":"Serra","sequence":"first","affiliation":[],"role":[{"role":"editor","vocabulary":"crossref"}]}],"short-title":[],"issued":{"date-parts":[[2021,5,18]]},"references-count":28,"journal-issue":{"issue":"5","published-online":{"date-parts":[[2021,5,18]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0249964","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,5,18]]}}}