[HIV infection, hepatitis B and C and syphilis in homeless people, in the city of São Paulo, Brazil].

Objective: To estimate the prevalence of HIV infections, as well as hepatitis B and C and syphilis viruses in homeless people.

Methods: Cross-sectional study with educational intervention, conducted in the city of São Paulo, between 2002 and 2003. A convenience sample of homeless people who used night shelters was selected, according to the following criteria: aged 18 or older and not showing psychiatric disturbances.