The infected inmates need health care that is often unavailable in prison, and their fellow prisoners need protection from contracting the virus.
In prisons, isolation rooms for each infected inmate exhausts air directly outside.
But the total number of infected inmates is growing because prison population growth is so explosive.
In New York State, the estimate of 9,500 infected inmates is based on what are known as "blinded" blood tests.
The advent of protease inhibitors has also increased the importance of identifying infected inmates.
'Freaks, Not People' Hostility by prison employees is a longstanding concern of infected inmates here, and in comparable institutions around the country.
Diseases that fester in prison spill over into society as a whole when the infected inmates return to the streets.
Many of those infected inmates were then released, and they spread the disease to 15,000 civilians.
A similar pattern has emerged with AIDS as infected inmates leave prison and infect people outside, who then turn to the public health system.
In North Carolina, infected inmates get counseling, a 30-day supply of medications, a prescription for 30 more days and contact information for health service organizations before they are released.