Brazil / Risk Taking / Hepatitis C / Syphilis / Hepatitis B / Humans / Female / Male / Sexual Behavior / Aged / Middle Aged / Adult / Public health systems and services research / Condoms / Homeless Persons / Substance-Related Disorders / Hepatitis B Vaccines / Humans / Female / Male / Sexual Behavior / Aged / Middle Aged / Adult / Public health systems and services research / Condoms / Homeless Persons / Substance-Related Disorders / Hepatitis B Vaccines