HIV prevalence and risk factors in a Brazilian penitentiary.

HIV infection among prison inmates shows one of the highest prevalence rates for specific population subgroups, reaching as high as 17% in Brazil and elsewhere in the world. The present study aimed to estimate HIV antibody prevalence and risk factors for infection in male inmates at the Ribeirão Preto Penitentiary, São Paulo State, Brazil, from May to August 2003. Using simple random sampling, 333 participants were selected, answered a standardized questionnaire, and had blood samples collected. Enzyme-linked immunosorbent assay (ELISA) and indirect immunofluorescence were used for HIV serological diagnosis. Overall HIV prevalence among inmates was 5.7% (95%CI: 3.2-8.2). All variables associated with HIV antibodies in the univariate analysis were submitted to unconditional multivariate logistic regression. Independent predictors of HIV infection were: total prison sentence less than five years and sharing needles and syringes.