Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has the potential for rapid transmission in congregate settings. We describe the multidisciplinary response to an outbreak of coronavirus disease (COVID-19) in a large homeless shelter in Chicago, Illinois, USA. The response to the outbreak included 4 rounds of mass PCR testing of all staff and residents and subsequent isolation of persons who tested positive for SARS-CoV-2. We further describe the dynamics of the shelter outbreak by fitting a modified susceptible-exposed-infectious-recovered compartmental model incorporating the widespread SARS-CoV-2 testing and isolation measures implemented in this shelter. Our model demonstrates that rapid transmission of COVID-19 in the shelter occurred before the outbreak was detected; rates of transmission declined after widespread testing and isolation measures were put in place. Overall, we demonstrate the feasibility of mass PCR testing and isolation in congregate settings and suggest the necessity of prompt response to suspected COVID-19 outbreaks in homeless shelters.

严重急性呼吸综合征冠状病毒 2 (SARS-CoV-2) 具有在聚集环境中快速传播的潜力。我们描述了美国伊利诺伊州芝加哥市一个大型无家可归者收容所对冠状病毒病 (COVID-19) 爆发的多学科应对措施。应对疫情的措施包括对所有工作人员和居民进行 4 轮大规模 PCR 检测，并随后隔离 SARS-CoV-2 检测呈阳性的人员。我们通过拟合修改后的易感者-暴露-感染者-恢复隔间模型，结合该避难所中广泛实施的 SARS-CoV-2 检测和隔离措施，进一步描述了避难所爆发的动态。我们的模型表明，在检测到疫情爆发之前，COVID-19 就已在避难所中快速传播；在采取广泛的检测和隔离措施后，传播率有所下降。总体而言，我们证明了在聚集场所进行大规模 PCR 检测和隔离的可行性，并建议有必要对无家可归者收容所中疑似 COVID-19 疫情做出迅速反应。