Cohort-based testing identifies inmates with asymptomatic, presymptomatic COVID-19
Early cohort-based testing among inmates helped identify new asymptomatic and presymptomatic COVID-19 cases that likely would have been missed by symptom screening, according to a study published in Clinical Infectious Diseases.
“COVID-19 continues to cause significant morbidity and mortality worldwide. Correctional and detention facilities are at high risk of experiencing outbreaks,” Ashutosh Wadhwa, DVM, PhD, MS, health scientist with the CDC’s Center for Global Health, and colleagues wrote. “We aimed to evaluate cohort-based testing among detained persons exposed to laboratory-confirmed cases of SARS-CoV-2 in order to identify presymptomatic and asymptomatic cases.”
Between May 1 and May 19, two testing strategies were rolled out in 12 tiers or housing units at the Cook County Jail in Chicago. According to the study, inmates were asked to participate in either serial testing, which offered tests at three points over 14 days (n = 137), or a single test (n = 87). All participants were also offered an interview at the end of the 14 days.
Of the 224 detained individuals approached, 194 participated in the interview and 172 had at least one test. According to the study, of those who received a test, 19 were positive for COVID-19 17 in the serial testing group and two in the single-test group. Researchers reported that more than half of the newly identified cases were presymptomatic or symptomatic (n = 12; 63%). Among those who reported symptoms in the 2 weeks before testing, the most common symptoms were loss of taste or smell (47%), headache (32%) and chills (26%). Of the 151 individuals interviewed with negative test results, commonly reported symptoms in the 2 weeks prior included headache (15%) loss of taste or smell (8%), cough (8%), dyspnea (8%), chills (7%) and nasal congestion (7%).
“Our findings highlight the utility of cohort-based approaches to testing, which can effectively identify presymptomatic and asymptomatic cases compared to symptom screening alone. Further, timely and effective measures to separate infected detained persons (ie, cohorting and isolation in single-occupancy cells) and staff can mitigate continued transmission of SARS-CoV-2 in detention facilities,” the authors wrote. “Early testing of close contacts in quarantine, in conjunction with [infection prevention and control] and other mitigation measures, may slow transmission in correctional facilities and the surrounding community.”