Pre-Exposure Prophylaxis to Prevent HIV

Eligibility Details: Inclusion Criteria: - 18 - 64 years old - Able to give consent - "At risk" for HIV as defined by any of the following: 1. unprotected sex (in past 6 months) with 1 or more men of unknown HIV status 2. evaluated for an STI within 6 months prior to screening 3. sex in last 6 months with an HIV-infected partner 4. IDU with report of using previously used or shared needles in past 6 months or has been in a methadone, buprenorphine, or suboxone treatment program in past 6 months or engaging in high-risk sexual behaviors 5. individuals engaging in transactional sex (i.e sex for money, drugs, or housing) 6. Infrequently uses condoms during sex with 1 or more partners of unknown HIV status who are known to be at substantial risk of HIV infection (IDU or bisexual male partner) - CrCl ≥ 60 ml/min - HIV- uninfected women desiring PrEP Exclusion Criteria: - Active alcohol or drug use or dependence which may interfere with adherence to study requirements - HIV-infected at screening or enrollment - Estimated CrCl < 60 mL/min - Past participation in an HIV vaccine study - Positive Hepatitis B surface antigen test - Underlying medical condition with survival unlikely during follow-up period - Any condition that in the opinion of study staff would make participation in the study unsafe or interfere with achieving study objectives - Pregnant or breast feeding - Actively trying to achieve pregnancy