Prospective Cohort, Ecological
Study population and setting
The study objective was to quantify the changes in incidence of SARS-CoV-2 infections among people in Immigration and Customs Enforcement (ICE) custody in the United States from April 1 to August 31, 2020. The study used publicly available data and calculated new COVID-19 cases each month by subtracting cumulative counts at the end of each month from the month prior. Mean daily detained populations were assessed per month from the ICE Statistics Fiscal-Year 2020 dataset, and compared to that of the population in February, before the pandemic. Notably, testing patterns varied between facilities and over time: some facilities piloted universal testing, others only tested symptomatic presumed cases and all of their contacts, while others tested only symptomatic contacts of cases.
Summary of Main Findings
The study found that the mean detained population decreased by 45% from 39,319 in February to 21,591 in August. Cases were reported from 91 of 135 facilities (67.4%), though case distribution was unequal and 20 facilities had 71% of cases reported. The monthly cumulative incidence increased from April (1527 per 100,000 people) to August (6683 per 100,000 people), while the monthly testing rate fluctuated. The test positivity rate was 47% in April, decreased to 11% in July, then increased against to 18% in August. Overall, the number of cases among detained people increased each month from April to August. The monthly case rate was consistently higher among persons in ICE custody than in the US population at large, ranging from 5.7 times higher in April to 21.8 times higher in ICE facilities in June, and falling to 15.1 times higher in August 2020.
The study utilized publicly available data to examine the changes not only in case counts but in the testing rate and test positivity rates. This helped to explore whether the change in cases could be due to changes in testing rates, rather than the change in true incidence.
The study accuracy is subject to reporting, which is often unreliable in detention settings. For instance, reporting delays are common, and presumed positive clinical cases who do not receive testing are missing. Asymptomatic testing is not conducting, and ICE does not have a unified surveillance method in place to ensure standardized reporting across facilities. Over the summer, a handful of ICE facilities piloted universal testing, though this was in the extreme minority. Additionally, given that ICE continued to detain new individuals and transfer detained people between facilities, the case rate that they saw may stem from infections in community being brought to the facility. Additionally, the study did not examine the number of staff members who have been tested, and therefore it does not reflect the number of infections in ICE facilities overall, but only among those detained.
The study is one of the first to utilize publicly available data to examine the changes in infection rates at ICE facilities.
This review was posted on: 7 December 2020