U.S Jails and Prisons Can Miss 90% or More of COVID-19 Cases if Only Testing Persons with Reported Symptoms

August 20, 2020

By Catherine Morrow

Mass testing events in 16 prison and jail facilities within the United States demonstrated that rates of COVID-19 were much higher than previously reported. The results of the study are published in CDC’s August 21 MMWR report.

Authors found that mass testing events increased the total number of known COVID-19 cases in the detention facilities studied from 642 to 8,239.

Anne Spaulding, MD, MPH, associate professor in the department of epidemiology at the Rollins School of Public Health, is coauthor on the paper and urges the need for broad testing in correctional facilities, including in Georgia, which does not routinely conduct mass testing in its prisons. 

“Our paper showed that broad testing will provide an accurate measurement of the extent of COVID-19 outbreaks in correctional settings,” says Spaulding. “Many cases will not come to light if we rely on incarcerated persons to report symptoms, since over half the transmission of the disease is via persons without or before symptoms.”

Authors say that case surveillance from symptom-based testing alone has likely underestimated SARS-CoV-2 prevalence in correctional and detention facilities, and mass testing of incarcerated and detained persons, regardless of symptoms, combined with periodic retesting, can help identify infections and support prevention of widespread cases.

Mass testing among incarcerated and detained persons in the 16 facilities occurred during the period from April 11–May 20, 2020.