Objectives: We identified factors associated with testing HIV positive in a prison system performing voluntary HIV testing on inmates and estimated the number of undetected HIV cases to evaluate the efficacy of risk-factor-based HIV testing.
Methods: We used logistic regression to estimate associations between HIV serostatus and HIV risk behaviors, mental health, coinfection status, and sociodemographic characteristics for prisoners entering the North Carolina Department of Correction from January 2004 through May 2006. We estimated the number of undetected HIV cases on the basis of age-, gender-, and race-specific HIV prevalences among prisoners and in the state.
Results: Nearly 3.4% (718/21 419) of tested prisoners were HIV positive. The strongest risk factors for infection among men were having sex with men (odds ratio [OR] = 8.0), Black race (OR = 6.2), other non-White race (OR = 7.4), and being aged 35 to 44 years (OR = 4.1). The strongest risk factor among women was Black race (OR = 3.8). Among HIV-positive prisoners, 65% were coinfected with HCV. We estimated that between 24% (223) and 61% (1101) of HIV cases remained undetected.
Conclusions: The associations between HIV serostatus and a variety of factors highlight the potential limitations of risk-factor-based HIV testing in prisons, as do the high number of potential undetected HIV cases.