Trends in COVID-19 transmission across United States Immigrations and Customs Enforcement facilities and the effectiveness of prevention strategies, 2020-2022

Background: The Covid-19 pandemic has significantly increased the health risks posed to incarcerated populations, including individuals detained by the United States Immigration and Customs Enforcement agency (ICE). Despite the enactment of preventative strategies (Pandemic Response Requirement; PRR), it is unclear whether these policies have reduced Covid-19 transmission in ICE facilities. In this study, we describe trends in Covid-19 cases across ICE facilities and model the effects of two significant PRR policies (V5.0 and V6.0) on viral transmission to inform future infection prevention strategies.

Methodology: We estimated trends for a series of descriptive measures of Covid-19 transmission, including point prevalence, across the ICE detention system from March 2020 through January 2022. After identifying facilities with complete datasets, we estimated the effective reproductive number of Covid-19 (Rt) per facility. Finally, we used an interventional time series model to estimate the effects of two significant PRR policies on facility effective reproductive numbers and performed sensitivity analyses.

Findings: Across the ICE system, 37,720 cumulative cases of Covid-19 were reported through January 2022 with a median point prevalence of 3.295% (IQR:2.472 - 4.309%). Across the facilities included in the model (N=93 of 146), the median population-weighted effective reproductive number was Rt=1.279 (IQR: 1.091 – 1.532). PRR policies V5.0 and V6.0 were not associated with immediate effects (V5.0: -0.196, 95%CI of -0.591 – 0.199; V6.0: -0.076, 95%CI of -0.304 – 0.152) or sustained effects (V5.0: <0.001, 95%CI of -0.001 – 0.002; V6.0: 0.001, 95%CI of <0.001 – 0.002) on facility effective reproductive numbers. The effects of PRR policies were sensitive to the variations in the delay from policy enactment to implementation.

Interpretation: Revisions to ICE PRR policies to improve testing, screening, and vaccination strategies did not reduce the transmission of Covid-19 within detention facilities with peak transmission found months after the changes were enacted. We recommend a comprehensive evaluation of the effectiveness of current public health policies utilized in detention facilities and the development of novel strategies to reduce infection risk.