Seroprevalence of HIV, HCV and syphilis in Brazilian prisoners: preponderance of parenteral transmission.

ABSTRACT

Between November 1993 and April 1994, our physicians' team interviewed and took blood samples of 631 prisoners randomly drawn from the largest prison of South America, which counted about 4700 inmates at that time. The interview consisted of questions related to risk behaviour for HIV infection, and the subjects were asked to provide blood for serological tests for HIV, hepatitis C and syphilis. Our main purpose was to investigate the relationship between HCV and injecting drug use as related to HIV seropositivity. Participation in the study was voluntary and confidentiality was guaranteed. Overall prevalences found were as follows HIV 16% (95% confidence interval (CI) 13-19%); HCV 34% (95% CI 30-38%), and syphilis 18% (95% CI 15-21%). Acknowledged use of ever injecting drug was 22% and no other parenteral risk was reported. Our results, as compared with other studies in the same prison, suggest that HIV prevalence has been stable in recent years, and that the major risk factor for HIV infection in this population is parenteral exposure by injecting drug use.