Correctional facilities that resisted mass coronavirus testing for inmates erred in their decision to only test inmates with symptoms, leading to large initial undercounts, a recent study by the CDC suggested. The study released this week examined 13 prisons and jails in California, Colorado, Ohio and Texas, and three federal prisons in states that weren’t identified. Most of the institutions waited several days or weeks before the first identified case of COVID-19 and the beginning of mass inmate testing, the study found.