Investigation of SARS-CoV-2 Transmission Associated With a Large Indoor Convention — New York City, November–December 2021
Authors: Samira Sami, Libby Horter, Diana Valencia, Isabel Thomas, Mary Pomeroy, Brianna Walker, Sarah E. Smith-Jeffcoat, Jacqueline E. Tate, Hannah L. Kirking, Nang Thu Thu Kyaw, Rebecca Burns, Kathleen Blaney, Vajeera Dorabawila, Rebecca Hoen, Zachary Zirnhelt, Cody Schardin, Anna Uehara, Adam C. Retchless, Vance R. Brown, Yonathan Gebru, Charles Powell, Stephen M. Bart, Johanna Vostok, Hannah Lund, Jessica Kaess, Megan Gumke, Randy Propper, Deepam Thomas, Mojisola Ojo, Alison Green, Morgan Wieck, Erica Wilson, Ryan J. Hollingshead, Sheila V. Nunez, Dawn M. Saady, Charsey Cole Porse, Kyle Gardner, Daniel Drociuk, Julia Scott, Taidy Perez, Jim Collins, Julie Shaffner, Ian Pray, Laura T. Rust, Shane Brady, Janna L. Kerins, Richard A. Teran, Victoria Hughes, Victoria Sepcic, Eleanor W. Low, Sarah K. Kemble, Alexandra Berkley, Kate Cleavinger, Haytham Safi, Lindsey Martin Webb, Scott Hutton, Courtney Dewart, Kristen Dickerson, Eric Hawkins, Javeria Zafar, Anna Krueger, Dena Bushman, Bailee Ethridge, Katrina Hansen, Jake Tant, Christy Reed, Carla Boutwell, Jennifer Hanson, Meagan Gillespie, Matthew Donahue, Pilar Lane, Ruby Serrano, Lorena Hernandez, Michelle A. Dethloff, Ruth Lynfield, Kathryn Como-Sabetti, Emily Lutterloh, Joel Ackelsberg, Jessica N. Ricaldi
Journal: MMWR Morbidity and Mortality Weekly Report (2022)

During November 19-21, 2021, an indoor convention (event) in New York City (NYC), was attended by approximately 53,000 persons from 52 U.S. jurisdictions and 30 foreign countries. In-person registration for the event began on November 18, 2021. The venue was equipped with high efficiency particulate air (HEPA) filtration, and attendees were required to wear a mask indoors and have documented receipt of at least 1 dose of a COVID-19 vaccine.* On December 2, 2021, the Minnesota Department of Health reported the first case of community-acquired COVID-19 in the United States caused by the SARS-CoV-2 B.1.1.529 (Omicron) variant in a person who had attended the event (1). CDC collaborated with state and local health departments to assess event-associated COVID-19 cases and potential exposures among U.S.-based attendees using data from COVID-19 surveillance systems and an anonymous online attendee survey. Among 34,541 attendees with available contact information, surveillance data identified test results for 4,560, including 119 (2.6%) persons from 16 jurisdictions with positive SARS-CoV-2 test results. Most (4,041 [95.2%]), survey respondents reported always wearing a mask while indoors at the event. Compared with test-negative respondents, test-positive respondents were more likely to report attending bars, karaoke, or nightclubs, and eating or drinking indoors near others for at least 15 minutes. Among 4,560 attendees who received testing, evidence of widespread transmission during the event was not identified. Genomic sequencing of 20 specimens identified the SARS-CoV-2 B.1.617.2 (Delta) variant (AY.25 and AY.103 sublineages) in 15 (75%) cases, and the Omicron variant (BA.1 sublineage) in five (25%) cases. These findings reinforce the importance of implementing multiple, simultaneous prevention measures, such as ensuring up-to-date vaccination, mask use, physical distancing, and improved ventilation in limiting SARS-CoV-2 transmission, during large, indoor events.