"The percentage of State prison inmates who were HIV positive was
"1.3% of those who never used drugs
"1.7% of those who had ever used drugs
"1.9% of those who used drugs in the month before their current offense
"2.8% of those who had used a needle to inject drugs
"5.1% of those who had shared a needle.
"Like State inmates, Federal inmates who used a needle and shared a needle had higher rates of HIV infection than those inmates who reported ever using drugs or using drugs in the month before their current offense."
Maruschak, Laura M. HIV In Prisons, 2004. NCJ-213897. Washington, DC: Department of Justice, Bureau of Justice Statistics, Nov. 2006.