Incidence of Multisystem Inflammatory Syndrome in Children Among US Persons Infected With SARS-CoV-2
Authors: Amanda B. Payne, Zunera Gilani, Shana Godfred-Cato, Ermias D. Belay, Leora R. Feldstein, Manish M. Patel, Adrienne G. Randolph, Margaret Newhams, Deepam Thomas, Reed Magleby, Katherine Hsu, Meagan Burns, Elizabeth Dufort, Angie Maxted, Michael Pietrowski, Allison Longenberger, Sally Bidol, Justin Henderson, Lynn Sosa, Alexandra Edmundson, Melissa Tobin-D’Angelo, Laura Edison, Sabrina Heidemann, Aalok R. Singh, John S. Giuliano, Lawrence C. Kleinman, Keiko M. Tarquinio, Rowan F. Walsh, Julie C. Fitzgerald, Katharine N. Clouser, Shira J. Gertz, Ryan W. Carroll, Christopher L. Carroll, Brooke E. Hoots, Carrie Reed, F. Scott Dahlgren, Matthew E. Oster, Timmy J. Pierce, Aaron T. Curns, Gayle E. Langley, Angela P. Campbell, Neha Balachandran, Thomas S. Murray, Cole Burkholder, Troy Brancard, Jenna Lifshitz, Dylan Leach, Ian Charpie, Cory Tice, Susan E. Coffin, Dana Perella, Kaitlin Jones, Kimberly L. Marohn, Phoebe H. Yager, Neil D. Fernandes, Heidi R. Flori, Monica L. Koncicki, Karen S. Walker, Maria Cecilia Di Pentima, Simon Li, Steven M. Horwitz, Sunanda Gaur, Dennis C. Coffey, Ilana Harwayne-Gidansky, Saul R. Hymes, Neal J. Thomas, Kate G. Ackerman, Jill M. Cholette
Journal: JAMA Network Open (2021)

Multisystem inflammatory syndrome in children (MIS-C) is associated with recent or current SARS-CoV-2 infection. Information on MIS-C incidence is limited.To estimate population-based MIS-C incidence per 1 000 000 person-months and to estimate MIS-C incidence per 1 000 000 SARS-CoV-2 infections in persons younger than 21 years.This cohort study used enhanced surveillance data to identify persons with MIS-C during April to June 2020, in 7 jurisdictions reporting to both the Centers for Disease Control and Prevention national surveillance and to Overcoming COVID-19, a multicenter MIS-C study. Denominators for population-based estimates were derived from census estimates; denominators for incidence per 1 000 000 SARS-CoV-2 infections were estimated by applying published age- and month-specific multipliers accounting for underdetection of reported COVID-19 case counts. Jurisdictions included Connecticut, Georgia, Massachusetts, Michigan, New Jersey, New York (excluding New York City), and Pennsylvania. Data analyses were conducted from August to December 2020.Race/ethnicity, sex, and age group (ie, ≤5, 6-10, 11-15, and 16-20 years).Overall and stratum-specific adjusted estimated MIS-C incidence per 1 000 000 person-months and per 1 000 000 SARS-CoV-2 infections.In the 7 jurisdictions examined, 248 persons with MIS-C were reported (median [interquartile range] age, 8 [4-13] years; 133 [53.6%] male; 96 persons [38.7%] were Hispanic or Latino; 75 persons [30.2%] were Black). The incidence of MIS-C per 1 000 000 person-months was 5.1 (95% CI, 4.5-5.8) persons. Compared with White persons, incidence per 1 000 000 person-months was higher among Black persons (adjusted incidence rate ratio [aIRR], 9.26 [95% CI, 6.15-13.93]), Hispanic or Latino persons (aIRR, 8.92 [95% CI, 6.00-13.26]), and Asian or Pacific Islander (aIRR, 2.94 [95% CI, 1.49-5.82]) persons. MIS-C incidence per 1 000 000 SARS-CoV-2 infections was 316 (95% CI, 278-357) persons and was higher among Black (aIRR, 5.62 [95% CI, 3.68-8.60]), Hispanic or Latino (aIRR, 4.26 [95% CI, 2.85-6.38]), and Asian or Pacific Islander persons (aIRR, 2.88 [95% CI, 1.42-5.83]) compared with White persons. For both analyses, incidence was highest among children aged 5 years or younger (4.9 [95% CI, 3.7-6.6] children per 1 000 000 person-months) and children aged 6 to 10 years (6.3 [95% CI, 4.8-8.3] children per 1 000 000 person-months).In this cohort study, MIS-C was a rare complication associated with SARS-CoV-2 infection. Estimates for population-based incidence and incidence among persons with infection were higher among Black, Hispanic or Latino, and Asian or Pacific Islander persons. Further study is needed to understand variability by race/ethnicity and age group.