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Volume 28, Number 1—January 2022

Multistate Outbreak of SARS-CoV-2 Infections, Including Vaccine Breakthrough Infections, Associated with Large Public Gatherings, United States

Radhika Gharpure1, Samira Sami1, Johanna Vostok, Hillary Johnson, Noemi Hall, Anne Foreman, Rebecca T. Sabo, Petra L. Schubert, Hanna Shephard, Vance R. Brown, Ben Brumfield, Jessica N. Ricaldi, Andrew B. Conley, Lindsay Zielinski, Lenka Malec, Alexandra P. Newman, Michelle Chang, Lauren E. Finn, Cameron Stainken, Anil T. Mangla, Patrick Eteme, Morgan Wieck, Alison Green, Alexandra Edmundson, Diana Reichbind, Vernell Brown, Laura Quiñones, Allison Longenberger, Elke Hess, Megan Gumke, Alicia Manion, Hannah Thomas, Carla A. Barrios, Adrianna Koczwara, Thelonious W. Williams, Marcia Pearlowitz, Moussokoura Assoumou, Alessandra F. Senisse Pajares, Hope Dishman, Cody Schardin, Xiong Wang, Kendalyn Stephens, Nakema S. Moss, Gurpalik Singh, Christine Feaster, Lindsey Martin Webb, Anna Krueger, Kristen Dickerson, Courtney Dewart, Bree Barbeau, Amelia Salmanson, Lawrence C. Madoff, Julie M. Villanueva, Catherine M. Brown2, and A. Scott Laney2Comments to Author 
Author affiliations: Centers for Disease Control and Prevention, Atlanta, Georgia, USA (R. Gharpure, S. Sami, N. Hall, A. Foreman, R.T. Sabo, V.R. Brown, B. Brumfield, J.N. Ricaldi, C. Dewart, J.M. Villanueva, A.S. Laney); Massachusetts Department of Public Health, Boston, Massachusetts, USA (J. Vostok, H. Johnson, P.L. Schubert, H. Shephard, L.C. Madoff, C.M. Brown); Council of State and Territorial Epidemiologists Applied Epidemiology Fellowship, Atlanta (H. Shephard, A. Edmundson); Georgia Institute of Technology, Atlanta (A.B. Conley); New York City Department of Health and Mental Hygiene, New York, New York, USA (L. Zielinski, L. Malec); New York State Department of Health, Albany, New York, USA (A.P. Newman); Los Angeles County Department of Public Health, Los Angeles, California, USA (M. Chang, L.E. Finn); California Department of Public Health, Richmond, California, USA (C. Stainken); DC Health, Washington, DC, USA (A.T. Mangla, P. Eteme); Rhode Island Department of Health, Providence, Rhode Island, USA (M. Wieck, A. Green); Connecticut Department of Public Health, Hartford, Connecticut, USA (A. Edmundson, D. Reichbind); CDC Foundation, Atlanta (D. Reichbind, C.A. Barrios, T.W. Williams); Philadelphia Department of Public Health, Philadelphia, Pennsylvania, USA (V. Brown Jr., L. Quiñones); Pennsylvania Department of Health, Harrisburg, Pennsylvania, USA (A. Longenberger, E. Hess); Florida Department of Health, Tallahassee, Florida, USA (M. Gumke); New Hampshire Department of Health and Human Services, Concord, New Hampshire, USA (A. Manion, H. Thomas); Chicago Department of Public Health, Chicago, Illinois, USA (C.A. Barrios, A. Koczwara); Maryland Department of Health, Baltimore, Maryland, USA (T.W. Williams, M. Pearlowitz); Alexandria Health Department, Alexandria, Virginia, USA (M. Assoumou); Virginia Department of Health, Richmond, Virginia, USA (A.F. Senisse Pajares); Georgia Department of Public Health, Atlanta (H. Dishman); Minnesota Department of Health, St. Paul, Minnesota, USA (C. Schardin, X. Wang); North Carolina Department of Health and Human Services, Raleigh, North Carolina, USA (K. Stephens); Alabama Department of Public Health, Montgomery, Alabama, USA (N.S. Moss); Indiana Department of Health, Indianapolis, Indiana, USA (G. Singh, C. Feaster); Colorado Department of Public Health and Environment, Denver, Colorado, USA (L.M. Webb); Maine Center for Disease Control and Prevention, Augusta, Maine, USA (A. Krueger); Ohio Department of Health, Columbus, Ohio, USA (K. Dickerson, C. Dewart); Utah Department of Health, Salt Lake City, Utah, USA (B. Barbeau, A. Salmanson)

Main Article

Table 2

Demographic and clinical characteristics of persons who had cluster-associated cases of SARS-CoV-2 infection, by primary and secondary case classification, after large public gatherings in Provincetown, Massachusetts, USA, July 2021*

Characteristic Case classification†
Primary case, n = 26 Secondary case, n = 30
Sex n = 26 n = 29
M 22 (85) 15 (52)
4 (15)
14 (48)
Age group, y n = 26 n = 30
<1–11 0 5 (17)
12–18 0 0
19–49 20 (77) 16 (53)
50–64 5 (19) 8 (27)
65–74 1 (4) 0
1 (3)
Race/ethnic group n = 24 n = 25
Hispanic or Latino 1 (4) 3 (12)
Non-Hispanic White 16 (67) 13 (52)
Non-Hispanic Black 1 (4) 0
Non-Hispanic other race or multiracial
6 (25)
9 (36)
Residence n = 26 n = 30
Provincetown 0 0
Other area in Massachusetts 17 (65) 17 (57)
Not in Massachusetts
9 (35)
13 (43)
Vaccination status‡ n = 26 n = 30
Fully vaccinated
21 (81)
18 (60)
Previous COVID-19 illness§ n = 24 n = 29
Previous COVID-19 diagnosis 1 (4) 1 (3)
Duration since previous positive test result, d
Underlying medical conditions¶ n = 26 n = 30
7 (27)
3 (10)
Symptoms n = 25 n = 26
Asymptomatic 1 (4) 1 (4)
24 (96)
25 (96)
Symptoms reported n = 24 n = 22
Abdominal pain 3 (13) 1 (5)
Chills 13 (54) 7 (32)
Congestion 14 (58) 13 (59)
Cough 16 (67) 14 (64)
Diarrhea 6 (25) 5 (23)
Difficulty breathing/shortness of breath 3 (13) 1 (5)
Fatigue 14 (58) 13 (59)
Fever 17 (71) 10 (45)
Headache 11 (46) 13 (59)
Loss of appetite 10 (42) 4 (18)
Loss of smell or taste 12 (50) 13 (59)
Muscle aches/pains 14 (58) 8 (36)
Sore throat 10 (42) 9 (41)
1 (4)
Symptom count
Median 6 5
Range 1–13 1–10
Interquartile range
Time from symptom onset to specimen collection date, d n = 23 n = 23
Median 2 2
Range 0–9 −1 to 6
Interquartile range 1–3 1–4
Clinical course n = 26 n = 30
Admitted to hospital 1 (4) 0
Admitted to intensive care unit 0 0

*Values are no. (%) unless indicated otherwise. Percentages might not total 100% because of rounding. Denominators for individual variables exclude cases that have missing data. COVID-19, coronavirus disease; SARS-CoV-2, severe acute respiratory syndrome coronavirus 2.

†A primary case was defined as detection of SARS-CoV-2 RNA or antigen in a respiratory specimen collected from a person <14 d after travel to or residence in Provincetown during July 3–17. A secondary case was defined as detection of SARS-CoV-2 RNA or antigen in a respiratory specimen collected from a person <14 d after close contact (within 6 feet for a cumulative total of >15 min within a 24-h period) with a person who had a primary case during their infectious period, and without history of travel to or residence in Provincetown during July 3–August 10. Secondary cases do not include chains of transmission occurring within visitors/residents in Provincetown. The infectious period of a person with a primary case was defined as 2 d previously through 10 d after symptom onset or, if asymptomatic, 2 d previously through 10 d after a positive test result. Only primary cases associated with a secondary case are presented.

‡Fully vaccinated persons were those who were >14 d after completion of all recommended doses of a US Food and Drug Administration‒authorized COVID-19 vaccine (2 doses of Pfizer/BioNTech [] or Moderna [], or 1 dose of Johnson & Johnson []), with documentation in their state immunization information system or self-report of vaccination details during case investigation.

§Previous COVID-19 illness was defined as detection of SARS-CoV-2 RNA or antigen in a respiratory specimen >90 d before collection of the cluster-associated specimen.

¶Persons who had underlying medical conditions associated with increased risk for severe COVID-19, including active cancer, autoimmune disease, cardiovascular disease, chronic kidney disease, chronic liver disease, chronic lung disease, current pregnancy, diabetes, solid organ or stem cell transplant, infection with HIV, and other immunocompromising conditions (13).

Main Article

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1These authors contributed equally to this article.

2These senior authors contributed equally to this article.

Page created: November 05, 2021
Page updated: December 20, 2021
Page reviewed: December 20, 2021
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