• 1. decrease in the number and proportion of times participants practiced vaginal or anal sex without a condom.
  
• 2. decrease in the overall number of persons participants shared syringes or injection equipment with.
  
• 3. decrease in the number and proportion of injections done with a syringe previously used by another person.
  
• 4. decrease in the number and proportion of times participant used another person's equipment to prepare or divide drugs before injecting.
  

• 1. decrease the incidence of HCV infection.
  
• 2. decrease the frequency of injecting in high-risk settings.
  
• 3. increase the frequency of drug treatment entry or decrease the frequency of injection drug use.
  

CIDUS III/DUIT is a five-city (Baltimore, Chicago, Los Angeles, New York, and Seattle) randomized controlled trial to develop and evaluate the efficacy of a six-session behavioral intervention for HIV and HCV uninfected injection drug users between the ages of 15 and 30 years. The primary goals of the intervention are to:

1. decrease the shared use of syringes and other injection paraphernalia,
2. decrease sexual risk behaviors associated with HIV and HCV infection, and
3. decrease the incidence of hepatitis C virus (HCV) infection.

The intervention arm consists of six small-group training and skills-building sessions to teach and reinforce peer education activities around decreasing sex and injection risk behaviors for HIV and HCV infection. In the fifth session, participants practice peer education around sex or injection risk behaviors within their community. The control arm consists of six video and discussion sessions to control for attention. Prior to study enrollment, all participants in both arms receive HIV and HCV testing with client-centered pre- and post-test counseling to also control for the demand for risk reduction information. Behavioral assessments (by audio computer assisted self interviewing) and blood draws (for serologic testing) occur at baseline, 3 and 6 month follow-up. 3285 participants completed the baseline visit, of whom 1564 tested HIV and HCV seronegative and returned for test results making them eligible to enroll in the intervention trial. Of the eligible participants, 854 were randomized into the trial. 606 and 591 returned for 3 and 6 month follow-up assessments, respectively, and 712 participants completed at least one follow-up visit.