{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,17]],"date-time":"2026-06-17T17:00:04Z","timestamp":1781715604483,"version":"3.54.5"},"reference-count":20,"publisher":"Public Library of Science (PLoS)","issue":"7","license":[{"start":{"date-parts":[[2021,7,14]],"date-time":"2021-07-14T00:00:00Z","timestamp":1626220800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/publicdomain\/zero\/1.0\/"}],"funder":[{"DOI":"10.13039\/100000030","name":"Centers for Disease Control and Prevention","doi-asserted-by":"publisher","award":["1U01GH002084"],"award-info":[{"award-number":["1U01GH002084"]}],"id":[{"id":"10.13039\/100000030","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":["www.plosone.org"],"crossmark-restriction":false},"short-container-title":["PLoS ONE"],"abstract":"<jats:sec id=\"sec001\"><jats:title>Background<\/jats:title><jats:p>Thailand was the first country outside China to report SARS-CoV-2 infected cases. Since the detection of the first imported case on January 12<jats:sup>th<\/jats:sup>, 2020 to the time this report was written, Thailand experienced two waves of community outbreaks (March-April 2020 and December 2020-March 2021). We examined prevalence of SARS-CoV-2 seropositivity among healthcare providers (HCPs) in four hospitals approximately one year after SARS-CoV-2 first detected in Thailand. By March 2021, these hospitals have treated a total of 709 coronavirus disease 2019 (COVID-19) patients.<\/jats:p><\/jats:sec><jats:sec id=\"sec002\"><jats:title>Methods<\/jats:title><jats:p>Blood specimens, collected from COVID-19 unvaccinated HCPs during January-March 2021, were tested for the presence of SARS-CoV-2 immunoglobulin G (IgG) antibodies to nucleocapsid (IgG-nucleocapsid) and spike (IgG-spike) proteins using Euroimmune<jats:sup>\u00ae<\/jats:sup>enzyme-linked immunosorbent assays.<\/jats:p><\/jats:sec><jats:sec id=\"sec003\"><jats:title>Results<\/jats:title><jats:p>Of 600 HCPs enrolled, 1 (0.2%) tested positive for the SARS-CoV-2 IgG-spike antibodies, but not the IgG-nucleocapsid.<\/jats:p><\/jats:sec><jats:sec id=\"sec004\"><jats:title>Conclusion<\/jats:title><jats:p>The presence of SARS-CoV-2 IgG antibodies was rare in this sample of HCPs, suggesting that this population remains susceptible to SARS-CoV-2 infection.<\/jats:p><\/jats:sec>","DOI":"10.1371\/journal.pone.0254563","type":"journal-article","created":{"date-parts":[[2021,7,14]],"date-time":"2021-07-14T17:29:11Z","timestamp":1626283751000},"page":"e0254563","update-policy":"https:\/\/doi.org\/10.1371\/journal.pone.corrections_policy","source":"Crossref","is-referenced-by-count":10,"title":["Sero-surveillance for SARS-CoV-2 infection among healthcare providers in four hospitals in Thailand one year after the first community outbreak"],"prefix":"10.1371","volume":"16","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-2295-4388","authenticated-orcid":true,"given":"Wanitchaya","family":"Kittikraisak","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0166-7336","authenticated-orcid":true,"given":"Phunlerd","family":"Piyaraj","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Apichat","family":"Vachiraphan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Thanapat","family":"Wongrapee","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Somsak","family":"Punjasamanvong","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Taweewun","family":"Hunsawong","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chalinthorn","family":"Sinthuwattanawibool","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chaniya","family":"Leepiyasakulchai","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pornsak","family":"Yoocharoen","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Eduardo","family":"Azziz-Baumgartner","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Joshua A.","family":"Mott","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Suthat","family":"Chottanapund","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"340","published-online":{"date-parts":[[2021,7,14]]},"reference":[{"issue":"12","key":"pone.0254563.ref001","doi-asserted-by":"crossref","first-page":"e003097","DOI":"10.1136\/bmjgh-2020-003097","article-title":"Infection and mortality of healthcare workers worldwide from COVID-19: a systematic review","volume":"5","author":"S Bandyopadhyay","year":"2020","journal-title":"BMJ Glob Health"},{"issue":"9","key":"pone.0254563.ref002","doi-asserted-by":"crossref","first-page":"1378","DOI":"10.3390\/microorganisms8091378","article-title":"Healthcare-associated SARS-CoV-2 transmiession-experiences from a German University Hospital","volume":"8","author":"CL Correa-Mart\u00ednez","year":"2020","journal-title":"Microorganisms"},{"key":"pone.0254563.ref003","unstructured":"Department of Disease Control. Corona virus disease (COVID-19): Thailand situation Nonthaburi, Thailand: Ministry of Public Health of Thailand; 2021 [https:\/\/ddc.moph.go.th\/viralpneumonia\/eng\/index.php."},{"issue":"16","key":"pone.0254563.ref004","doi-asserted-by":"crossref","first-page":"2027","DOI":"10.1093\/cid\/ciaa344","article-title":"Antibody responses to SARS-CoV-2 in patients with novel coronavirus disease 2019","volume":"71","author":"J Zhao","year":"2020","journal-title":"Clin Infect Dis"},{"issue":"12","key":"pone.0254563.ref005","doi-asserted-by":"crossref","first-page":"2974","DOI":"10.3201\/eid2612.203334","article-title":"Antibody profiles according to mild or severe SARS-CoV-2 infection, Atlanta, Georgia, USA, 2020","volume":"26","author":"WT Hu","year":"2020","journal-title":"Emerg Infect Dis"},{"issue":"8","key":"pone.0254563.ref006","doi-asserted-by":"crossref","first-page":"791","DOI":"10.1099\/jgv.0.001439","article-title":"The dynamics of humoral immune responses following SARS-CoV-2 infection and the potential for reinfection","volume":"101","author":"P Kellam","year":"2020","journal-title":"J Gen Virol"},{"key":"pone.0254563.ref007","doi-asserted-by":"crossref","first-page":"147","DOI":"10.1016\/j.jinf.2020.03.012","article-title":"Profile of specific antibodies to SARS-CoV-2: The first report","volume":"81","author":"AT Xiao","year":"2020","journal-title":"J Infect"},{"issue":"18","key":"pone.0254563.ref008","first-page":"1848","article-title":"Antibodies in infants born to mothers with COVID-19 pneumonia","volume":"323","author":"H Zeng","year":"2020","journal-title":"JAMA"},{"issue":"10","key":"pone.0254563.ref009","first-page":"1562","article-title":"Duration of antibody responses after severe acute respiratory syndrome","volume":"13","author":"LP Wu","year":"2020","journal-title":"Emerg Infect Dis"},{"key":"pone.0254563.ref010","unstructured":"Centers for Disease Control and Prevention. Interim guidelines for collecting and handling of clinical specimens for COVID-19 testing: Centers for Disease Control and Prevention; 2021 [https:\/\/www.cdc.gov\/coronavirus\/2019-ncov\/lab\/guidelines-clinical-specimens.html."},{"issue":"18","key":"pone.0254563.ref011","doi-asserted-by":"crossref","first-page":"1708","DOI":"10.1056\/NEJMoa2002032","article-title":"Clinical characteristics of 2019 novel coronavirus infection in China","volume":"382","author":"W Guan","year":"2020","journal-title":"N Engl J Med"},{"key":"pone.0254563.ref012","doi-asserted-by":"crossref","first-page":"288","DOI":"10.1016\/j.cca.2020.06.032","article-title":"Impact of heat-inactivation on the detection of SARS-CoV-2 IgM and IgG antibody by ELISA","volume":"509","author":"X Hu","year":"2020","journal-title":"Clin Chim Acta"},{"issue":"7","key":"pone.0254563.ref013","doi-asserted-by":"crossref","first-page":"735","DOI":"10.3390\/v12070735","article-title":"Heat inactivation of different types of SARS-CoV-2 samples: What protocols for biosafety, molecular detection and serological diagnostics?","volume":"12","author":"B Pastorino","year":"2020","journal-title":"Viruses"},{"issue":"2","key":"pone.0254563.ref014","doi-asserted-by":"crossref","first-page":"67","DOI":"10.55374\/jseamed.v4i2.76","article-title":"COVID-19 seroprevalence among royal Thai army personnel in Bangkok Metropolitan area from July-September 2020","volume":"4","author":"N Sansanayudh","year":"2020","journal-title":"J Southeast Asian Med Res"},{"issue":"4","key":"pone.0254563.ref015","doi-asserted-by":"crossref","first-page":"e0238088","DOI":"10.1371\/journal.pone.0238088","article-title":"Seroprevalence of hospital staff in a province with zero COVID-19 cases","volume":"16","author":"T Nopsopon","year":"2021","journal-title":"PLoS One"},{"key":"pone.0254563.ref016","article-title":"COVID-19 antibody in Thai community hospitals","author":"T Nopsopon","year":"2020","journal-title":"medRxiv"},{"issue":"7","key":"pone.0254563.ref017","doi-asserted-by":"crossref","first-page":"1478","DOI":"10.3201\/eid2607.200841","article-title":"Severe acute respiratory syndrome coronavirus 2-specific antibody responses in coronavirus disease patients","volume":"26","author":"NMA Okba","year":"2020","journal-title":"Emerg Infect Dis"},{"issue":"7","key":"pone.0254563.ref018","doi-asserted-by":"crossref","first-page":"1580","DOI":"10.3201\/eid2607.200598","article-title":"Clinical characteristics of patients hospitalized with coronavirus disease, Thailand","volume":"26","author":"WA Pongpirul","year":"2020","journal-title":"Emerg Infect Dis"},{"key":"pone.0254563.ref019","unstructured":"Grebe E, Busch MP. Comparative evaluation of high-throughput commercially available SARS-CoV-2 serologic assays for sero surveillance applications. WHO Solidarity II. 2021."},{"issue":"4","key":"pone.0254563.ref020","doi-asserted-by":"crossref","first-page":"518","DOI":"10.1097\/EDE.0000000000001361","article-title":"Estimating the cumulative incidence of SARS-CoV-2 infection and the infection fatality ratio in light of waning antibodies","volume":"32","author":"K Shioda","year":"2021","journal-title":"Epidemiology"}],"container-title":["PLOS ONE"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0254563","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,1,4]],"date-time":"2023-01-04T06:01:14Z","timestamp":1672812074000},"score":1,"resource":{"primary":{"URL":"https:\/\/dx.plos.org\/10.1371\/journal.pone.0254563"}},"subtitle":[],"editor":[{"given":"Prasenjit","family":"Mitra","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"editor"}]}],"short-title":[],"issued":{"date-parts":[[2021,7,14]]},"references-count":20,"journal-issue":{"issue":"7","published-online":{"date-parts":[[2021,7,14]]}},"URL":"https:\/\/doi.org\/10.1371\/journal.pone.0254563","relation":{},"ISSN":["1932-6203"],"issn-type":[{"value":"1932-6203","type":"electronic"}],"subject":[],"published":{"date-parts":[[2021,7,14]]}}}