Travel history among persons infected with SARS-CoV-2 variants of concern in the United States, December 2020-February 2021

Alicia Dunajcik, Kambria Haire, Jennifer D Thomas, Leah F Moriarty, Yuri Springer, Julie M Villanueva, Adam MacNeil, Benjamin Silk, Jeffrey B Nemhauser, Ramona Byrkit, Melanie Taylor, Krista Queen, Suxiang Tong, Justin Lee, Dhwani Batra, Clinton Paden, Tiffany Henderson, Audrey Kunkes, Mojisola Ojo, Melanie FirestoneLindsey Martin Webb, Melissa Freeland, Catherine M Brown, Thelonious Williams, Krisandra Allen, Judy Kauerauf, Erica Wilson, Seema Jain, Eric McDonald, Elana Silver, Sarah Stous, Debra Wadford, Rachel Radcliffe, Chandra Marriott, Jennifer P Owes, Stephen M Bart, Lynn E Sosa, Kelly Oakeson, Natalie Wodniak, Julia Shaffner, Quanta Brown, Ryan Westergaard, Andrea Salinas, Sara Hallyburton, Yasmin Ogale, Tabatha Offutt-Powell, Kimberly Bonner, Sheri Tubach, Clay Van Houten, Victoria Hughes, Valerie Reeb, Chris Galeazzi, Shreya Khuntia, Sasha McGee, Joseph T Hicks, Dimple Dinesh Patel, Anna Krueger, Scott Hughes, Fabiana Jeanty, Jade C Wang, Ellen H Lee, Tracey Assanah-Deane, Megan Tompkins, Kendra Dougherty, Ozair Naqvi, Matthew Donahue, Justin Frederick, Baha Abdalhamid, Ann M Powers, Mark Anderson

Research output: Contribution to journalArticlepeer-review


The first three SARS-CoV-2 phylogenetic lineages classified as variants of concern (VOCs) in the United States (U.S.) from December 15, 2020 to February 28, 2021, Alpha (B.1.1.7), Beta (B.1.351), and Gamma (P.1) lineages, were initially detected internationally. This investigation examined available travel history of coronavirus disease 2019 (COVID-19) cases reported in the U.S. in whom laboratory testing showed one of these initial VOCs. Travel history, demographics, and health outcomes for a convenience sample of persons infected with a SARS-CoV-2 VOC from December 15, 2020 through February 28, 2021 were provided by 35 state and city health departments, and proportion reporting travel was calculated. Of 1,761 confirmed VOC cases analyzed, 1,368 had available data on travel history. Of those with data on travel history, 1,168 (85%) reported no travel preceding laboratory confirmation of SARS-CoV-2 and only 105 (8%) reported international travel during the 30 days preceding a positive SARS-CoV-2 test or symptom onset. International travel was reported by 92/1,304 (7%) of persons infected with the Alpha variant, 7/55 (22%) with Beta, and 5/9 (56%) with Gamma. Of the first three SARS-CoV-2 lineages designated as VOCs in the U.S., international travel was common only among the few Gamma cases. Most persons infected with Alpha and Beta variant reported no travel history, therefore, community transmission of these VOCs was likely common in the U.S. by March 2021. These findings underscore the importance of global surveillance using whole genome sequencing to detect and inform mitigation strategies for emerging SARS-CoV-2 VOCs.

Original languageEnglish (US)
Pages (from-to)e0001252
JournalPLOS global public health
Issue number3
StatePublished - 2023
Externally publishedYes

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Copyright: This is an open access article, free of all copyright, and may be freely reproduced, distributed, transmitted, modified, built upon, or otherwise used by anyone for any lawful purpose. The work is made available under the Creative Commons CC0 public domain dedication.

PubMed: MeSH publication types

  • Journal Article


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