Until now. And now, suddenly, almost all have it. Just in time for a couple paid weeks off for quarantine. How convenient. Nope, make them work with the positive prisoners. Why risk anyone else.
What cases as these indicate, along with states that now have a high infection rate that never had one before, is that those who never were infectious often inevitably become so, while those who get infected and recover - as almost all do - retain resistance against future possible reinfection. And thus unless a vaccine works and those who are in real danger of death get vaccinated, then the quarantine mode is pointless.