{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,22]],"date-time":"2026-06-22T23:12:40Z","timestamp":1782169960679,"version":"3.54.5"},"reference-count":14,"publisher":"Springer Science and Business Media LLC","issue":"1","license":[{"start":{"date-parts":[[2025,8,29]],"date-time":"2025-08-29T00:00:00Z","timestamp":1756425600000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"},{"start":{"date-parts":[[2025,8,29]],"date-time":"2025-08-29T00:00:00Z","timestamp":1756425600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0"}],"funder":[{"DOI":"10.13039\/100000738","name":"U.S. Department of Veterans Affairs","doi-asserted-by":"crossref","id":[{"id":"10.13039\/100000738","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":["link.springer.com"],"crossmark-restriction":false},"short-container-title":["J Occup Med Toxicol"],"abstract":"<jats:title>Abstract<\/jats:title>\n          <jats:sec>\n            <jats:title>Background<\/jats:title>\n            <jats:p>Occupational COVID-19 remains a challenge among healthcare personnel (HCP).<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Methods<\/jats:title>\n            <jats:p>This study documents three COVID-19 outbreaks that occurred among vaccinated HCP within a single health care system (HCS) in California, USA in June and August 2023. The Employee Health (EH) unit for the HCS conducted surveillance with structured interviews, identifying outbreaks in real-time.<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Results<\/jats:title>\n            <jats:p>In June, 10 of 25 staff (40%) at a rural outpatient clinic that serves the HCS contracted COVID-19. One week later, 10 of 90 staff (11%) at a second outpatient clinic were infected, with half the cases were staff of a single close-knit team. In August, a team-building retreat of staff from the main hospital of the HCS resulted in 15 of 23 participants (65%) contracting COVID-19. The combined attack rate for these outbreaks was 25% (95% CI: 18\u201332%).<\/jats:p>\n          <\/jats:sec>\n          <jats:sec>\n            <jats:title>Discussion<\/jats:title>\n            <jats:p>These outbreaks, despite high vaccination rates among the employees, reveal gaps in infection control, underscoring the need for stricter masking, improved ventilation, and rigorous surveillance testing. Rapid response to outbreaks and reinforcing education on symptom-based work exclusions are critical to preventing transmission among health care workers (HCWs) and their patients.<\/jats:p>\n          <\/jats:sec>","DOI":"10.1186\/s12995-025-00474-5","type":"journal-article","created":{"date-parts":[[2025,8,29]],"date-time":"2025-08-29T13:28:09Z","timestamp":1756474089000},"update-policy":"https:\/\/doi.org\/10.1007\/springer_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Outbreaks of COVID-19 among healthcare personnel in a U. S. veterans administration health care system site, June and August 2023"],"prefix":"10.1186","volume":"20","author":[{"given":"Ignacio A.","family":"Santana","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Max","family":"Blumberg","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Noreen","family":"Chan","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Margaret J.","family":"Ansay","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Phyllis C.","family":"Tien","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Paul D.","family":"Blanc","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sandeep","family":"Guntur","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"297","published-online":{"date-parts":[[2025,8,29]]},"reference":[{"issue":"5","key":"474_CR1","doi-asserted-by":"publisher","first-page":"253","DOI":"10.7883\/yoken.JJID.2023.464","volume":"77","author":"H Osaka","year":"2024","unstructured":"Osaka H, Tagashira Y, Takeuchi H, Tanaka Y, Tanimoto K, Gu Y. Nosocomial outbreak of SARS-CoV-2 in a hospital ward during the Omicron variant-dominant wave with a review of the relevant literature. Jpn J Infect Dis. 2024;77(5):253\u20139.","journal-title":"Jpn J Infect Dis"},{"issue":"1","key":"474_CR2","doi-asserted-by":"publisher","first-page":"e62","DOI":"10.1017\/ash.2024.40","volume":"4","author":"E Rios-Guzman","year":"2024","unstructured":"Rios-Guzman E, Stancovici AG, Simons LM, Barajas G, Glenn K, Weber RT, Ozer EA, Lorenzo-Redondo R, Hultquist JF, Bolon MK. COVID-19 outbreak and genomic investigation in an inpatient behavioral health unit. Antimicrob Steward Healthc Epidemiol. 2024;4(1):e62.","journal-title":"Antimicrob Steward Healthc Epidemiol"},{"issue":"4","key":"474_CR3","doi-asserted-by":"publisher","first-page":"686","DOI":"10.3390\/microorganisms12040686","volume":"12","author":"A Krishna","year":"2024","unstructured":"Krishna A, Tutt J, Grewal M, Bragdon S, Moreshead S. Outbreak of severe acute respiratory syndrome coronavirus 2 in a rural community hospital during Omicron predominance. Microorganisms. 2024;12(4):686.","journal-title":"Microorganisms"},{"issue":"1","key":"474_CR4","doi-asserted-by":"publisher","first-page":"91","DOI":"10.20411\/pai.v9i1.691","volume":"9","author":"C Jinadatha","year":"2024","unstructured":"Jinadatha C, Jones LD, Hailes JM, Marshall EK, Hwang M, Cadnum JL, Choi H, Chatterjee P, Chan ER, Zimmerman PA, Chakhtoura NGE, Saade EA, Donskey CJ. Transmission of severe acute respiratory syndrome coronavirus 2 among residents and employees in a veterans affairs community living center: a 42-month prospective cohort study. Pathog Immun. 2024;9(1):91\u2013107.","journal-title":"Pathog Immun"},{"issue":"1","key":"474_CR5","doi-asserted-by":"publisher","first-page":"9561","DOI":"10.1038\/s41598-024-60194-4","volume":"14","author":"AI Raja","year":"2024","unstructured":"Raja AI, Nicholls G, Coldwell M, van Veldhoven K, Sandys V, Atkinson B, Nicholls I, Spencer A, Graham A, Higgins H, Atchison C, Keen C, Fletcher T, Pearce N, Brickley EB, Chen Y. A SARS-CoV-2 outbreak investigation at a storage and distribution centre in england: an assessment of worker- and workplace-related risk factors. Sci Rep. 2024;14(1):9561.","journal-title":"Sci Rep"},{"issue":"7","key":"474_CR6","doi-asserted-by":"publisher","first-page":"475","DOI":"10.1093\/occmed\/kqad100","volume":"74","author":"G Nicholls","year":"2024","unstructured":"Nicholls G, Atkinson B, van Veldhoven K, Nicholls I, Coldwell M, Clarke A, Atchison CJ, Raja AI, Bennett AM, Morgan D, Pearce N, Fletcher T, Brickley EB, Chen Y. An outbreak of SARS-CoV-2 in a public-facing office in England. Occup Med (Lond). 2024;74(7):475\u201385.","journal-title":"Occup Med (Lond)"},{"issue":"1","key":"474_CR7","doi-asserted-by":"publisher","first-page":"1077","DOI":"10.1186\/s12889-023-16025-8","volume":"23","author":"A Graham","year":"2023","unstructured":"Graham A, Raja AI, van Veldhoven K, Nicholls G, Simpson A, Atkinson B, Nicholls I, Higgins H, Cooke J, Bennett A, Morgan D, Keen C, Fletcher T, Pearce N, Atchison C, Brickley EB, Chen Y. A SARS-CoV-2 outbreak in a plastics manufacturing plant. BMC Public Health. 2023;23(1):1077.","journal-title":"BMC Public Health"},{"issue":"4","key":"474_CR8","first-page":"235","volume":"74","author":"S B\u00fchler","year":"2023","unstructured":"B\u00fchler S, Busch P, Wittkamp P, Alpers K, Doerre A, Plenge-B\u00f6nig A, Forna\u00e7on J, Sch\u00e4fers C, Reichstein A, Grassl B, Hewelt E, Dirksen-Fischer M, Kleine-Kampmann S. A SARS-CoV-2 Omicron outbreak among crew members on a cruise ship in Germany in early 2022. Int Marit Health. 2023;74(4):235\u201342.","journal-title":"Int Marit Health"},{"issue":"4","key":"474_CR9","doi-asserted-by":"publisher","first-page":"535","DOI":"10.1007\/s12560-021-09500-1","volume":"13","author":"Y Mallet","year":"2021","unstructured":"Mallet Y, Pivette M, Revest M, Angot E, Valence M, Dupin C, Picard N, Brelivet G, Seyler T, Ballet S, Le Tertre A, Guillois Y. Identification of workers at increased risk of infection during a COVID-19 outbreak in a meat processing plant, france, May 2020. Food Environ Virol. 2021;13(4):535\u201343.","journal-title":"Food Environ Virol"},{"issue":"3","key":"474_CR10","doi-asserted-by":"publisher","first-page":"392","DOI":"10.1016\/j.ajic.2020.08.004","volume":"49","author":"TF Zabarsky","year":"2021","unstructured":"Zabarsky TF, Bhullar D, Silva SY, Mana TSC, Ertle MT, Navas ME, Donskey CJ. What are the sources of exposure in healthcare personnel with coronavirus disease 2019 infection? Am J Infect Control. 2021;49(3):392\u20135.","journal-title":"Am J Infect Control"},{"issue":"1","key":"474_CR11","doi-asserted-by":"publisher","first-page":"5","DOI":"10.1186\/s12912-023-01653-7","volume":"23","author":"P Chaudhary","year":"2024","unstructured":"Chaudhary P, Payal, Nain P, Pooja, Rana P, Verma P, Yadav P, Poonam, Prerna, Kashyap G, Kumar R. Perceived risk of infection, ethical challenges and motivational factors among frontline nurses in Covid-19 pandemic: prerequisites and lessons for future pandemic. BMC Nurs. 2024;23(1):5.","journal-title":"BMC Nurs"},{"key":"474_CR12","unstructured":"CDC. Centers for Disease Control and Prevention. Infection Control Guidance: SARS-CoV-2. Health Care Providers June 24, 2024, https:\/\/www.cdc.gov\/covid\/hcp\/infection-control\/?CDC_AAref_Val=https:\/\/www.cdc.gov\/coronavirus\/2019-ncov\/hcp\/infection-control-recommendations.html Accessed 5 June 2025."},{"issue":"3","key":"474_CR13","doi-asserted-by":"publisher","first-page":"226","DOI":"10.1016\/j.idh.2023.01.004","volume":"28","author":"Y Lu","year":"2023","unstructured":"Lu Y, Okpani AI, McLeod CB, Grant JM, Yassi A. Masking strategy to protect healthcare workers from COVID-19: an umbrella meta-analysis. Infect Dis Health. 2023;28(3):226\u201338.","journal-title":"Infect Dis Health"},{"issue":"12","key":"474_CR14","doi-asserted-by":"publisher","first-page":"2191","DOI":"10.1039\/D2EM00333C","volume":"24","author":"M Sheraz","year":"2022","unstructured":"Sheraz M, Mir KA, Anus A, Le VCT, Kim S, Nguyen VQ, et al. SARS-CoV-2 airborne transmission: a review of risk factors and possible preventative measures using air purifiers. Environ Sci Process Impacts. 2022;24(12):2191\u2013216.","journal-title":"Environ Sci Process Impacts"}],"container-title":["Journal of Occupational Medicine and Toxicology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s12995-025-00474-5.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/article\/10.1186\/s12995-025-00474-5\/fulltext.html","content-type":"text\/html","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/link.springer.com\/content\/pdf\/10.1186\/s12995-025-00474-5.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,9,10]],"date-time":"2025-09-10T05:33:29Z","timestamp":1757482409000},"score":1,"resource":{"primary":{"URL":"https:\/\/occup-med.biomedcentral.com\/articles\/10.1186\/s12995-025-00474-5"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,8,29]]},"references-count":14,"journal-issue":{"issue":"1","published-online":{"date-parts":[[2025,12]]}},"alternative-id":["474"],"URL":"https:\/\/doi.org\/10.1186\/s12995-025-00474-5","relation":{},"ISSN":["1745-6673"],"issn-type":[{"value":"1745-6673","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,8,29]]},"assertion":[{"value":"2 October 2024","order":1,"name":"received","label":"Received","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"30 July 2025","order":2,"name":"accepted","label":"Accepted","group":{"name":"ArticleHistory","label":"Article History"}},{"value":"29 August 2025","order":3,"name":"first_online","label":"First Online","group":{"name":"ArticleHistory","label":"Article History"}},{"order":1,"name":"Ethics","group":{"name":"EthicsHeading","label":"Declarations"}},{"value":"This quality improvement project was granted a waiver as exempt from review from further review from Institutional Review for Research with Human Subjects by the SFVAHCS.","order":2,"name":"Ethics","group":{"name":"EthicsHeading","label":"Ethics approval and consent to participate"}},{"value":"The manuscript was reviewed by all co-authors.","order":3,"name":"Ethics","group":{"name":"EthicsHeading","label":"Consent for publication"}},{"value":"Dr. Blanc is Co-Editor-in-Chief for the Journal of Occupational Medicine and Toxicology. There are no other potential conflicts of interest to declare.","order":4,"name":"Ethics","group":{"name":"EthicsHeading","label":"Competing interests"}}],"article-number":"27"}}