The investigators will recruit male Tajik migrants who inject drugs from 12 different sites in Moscow, including bazaars and other work sites. In both study arms, the recruited men (index participants) will be required to recruit two eligible MWID peers for interviews prior to being interviewed themselves. Participants will be randomly assigned to either the peer educator intervention program or the health education intervention program. After peer-recruited network members are enrolled and interviewed, the index participant will participate in the peer educator training or the control group activities. All participants and recruited network members will then be followed and re-interviewed at 3-month intervals for one year to assess changes in risky drug, alcohol, and sexual behaviors due to intervention participation and through diffusion to network members. The investigators will also collect data from voluntary HIV and HCV testing conducted at 6 months (HCV only) and at 12 months (HIV and HCV) post-intervention.
