Community Transmission of SARS-CoV-2 at Two Family Gatherings - Chicago, Illinois, February–March 2020

Ghinai et al examines the community transmission of SARS-CoV-2 at two family gatherings in Chicago IL from Feb to Mar 2020. SARS-CoV-2, the virus that causes coronavirus disease 2019 (COVID-19), has spread rapidly around the world since it was first recognized in late 2019. Most early reports of person-to-person SARS-CoV-2 transmission have been among household contacts, where the secondary attack rate has been estimated to exceed 10%, in health care facilities, and in congregate settings. However, widespread community transmission, as is currently being observed in the US requires more expansive transmission events between nonhousehold contacts. In February and March 2020, the Chicago Department of Public Health (CDPH) investigated a large, multifamily cluster of COVID-19. Patients with confirmed COVID-19 and their close contacts were interviewed to better understand nonhousehold, community transmission of SARS-CoV-2. Here, the cluster of 16 cases of confirmed or probable COVID-19 including three deaths, likely resulting from transmission of SARS-CoV-2 at two family gatherings, a funeral and a birthday party, are described.