HIV and infections of similar transmission patterns in a drug injectors community of Santos, Brazil

To study the prevalence of HIV and infections with related transmission patterns the authors interviewed and obtained blood samples from 220 injecting drug users (IDUs) sampled by snowballing from the city of Santos in the state of Sao Paulo Brazil where the estimated number of IDUs (10000) comprises about 2% of the entire population. Seroprevalence of HIV hepatitis B and C viruses (HBV and HCV) syphilis and HTLV (1 and 2) was assessed and compared with that in 197 blood donors from the same city matched for age and gender. Risk behavior related to HIV was assessed by a standard questionnaire applied to the IDU sample. Univariate and multivariate analyses of the risk factors were performed. Seroprevalences found were 62% for HIV 75% for HCV 75% for HBV 34% for syphilis and 25% for HTLV (1 and 2) among IDUs which compare with 0.0% 2% 23% 12% and 1% for blood donors respectively. The risk for parenterally transmitted infections in this IDU community was higher than that for sexually transmitted infections (odds ratio [OR] for syphilis 3.57; hepatitis B 10.0; hepatitis C 100). The results of the multivariate risk analysis showed that daily rate of ID use >5 times/day (OR = 6.73) not changing behavior to avoid AIDS (OR = 3.28) ID use >15 days/month (OR = 2.72) and ID use in the last 2 months (OR = 2.23) were the risk behaviors significantly associated with HIV infection. (authors)