Preventing Bacterial and Viral Infections Among Injection Drug Users

Inclusion Criteria: * 18 years of age or older * report injection of heroin, cocaine, or methamphetamine (meth) on at least three different days in the week prior to admission * have injected heroin, cocaine, or meth for at least three months * positive urine screen for heroin, cocaine, or meth Exclusion Criteria: * currently psychotic (e.g., responding to internal stimuli through observed hallucinations or delusions), homicidal or suicidal * cannot provide informed consent * not able to complete interviews in English (expected to exclude \<5% of IDUs) * in police custody, expecting incarceration * unable to provide names and contact information for at least two verifiable locator persons who will know where to find them for retention/follow-up purposes * plan to move out of the Boston area in the next 12 months.