Outbreak of COVID-19 and Interventions in One of the Largest Jails in the United States: Cook County, IL, 2020

Zawitz, C.; Welbel, S.; Ghinai, I.; Mennella, C.; Levin, R.; Samala, U.; Bryant Smith, M.; Gubser, J.; Jones, B.; Varela, K.; Kirbiyik, U.; Rafinski, J.; Fitzgerald, A.; Orris, P.; Bahls, A.; Black, S. R.; Binder, A. M.; Armstrong, P. A.

Background: Correctional and detention facilities are disproportionately affected by COVID-19 due to shared space, contact between staff and detained persons, and movement within facilities of detained persons, many with pre-existing medical conditions. On March 18, 2020, Cook County Jail, one of the United States' largest, identified its first suspected case of COVID-19 in a detained person. Methods: This analysis includes SARS-CoV-2 cases confirmed by molecular detection among detained persons and Cook County Sheriff's Office staff. We examined occurrence of symptomatic cases in each building and proportions of asymptomatic detained persons testing positive. We describe timing of interventions including social distancing, mask use, and expanded testing and show outbreak trajectory in the jail versus contemporaneous case counts in Chicago. Results: During March 1-April 30, 907 symptomatic and asymptomatic cases of SARS-CoV-2 infection were detected among detained persons (n = 628) and staff (n = 279), with nine deaths. Symptomatic cases occurred in all housing divisions; in 9/13 buildings, staff cases occurred first. Among asymptomatic detained persons in quarantine, 23.6% tested positive. Programmatic activity and visitation stopped March 9, cells were converted into single occupancy beginning March 26, and universal masking was implemented for staff (April 2) and detained persons (April 13). Cases at the jail declined while cases in Chicago increased. Conclusion: Aggressive intervention strategies coupled with widespread diagnostic testing of detained and staff populations can limit introduction and mitigate transmission of SARS-CoV-2 infection in correctional and detention facilities.