The Marshall Project is a non-profit journalism project that is tracking COVID-19 infections in state and federal prisons. Interactive data helps people see just how widespread COVID-19 is among prisons and the toll it is taking on prisoners and staff.

Much of the remarkable growth in coronavirus cases has been due to some states—Michigan, Ohio, Tennessee, Texas among them—that began aggressively testing nearly everyone at prisons where people had become sick. This spate of testing would suggest that coronavirus had been circulating in prisons in much greater numbers than known in the early weeks of the pandemic, and that in the many states where tests had not been prevalent, far more people may have been carrying it than were initially reported.

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