Protocol RV 583 Multinational Observational Cohort of HIV and Other Infections

This multinational observational study is following people who are at high risk for HIV and other sexually transmitted infections (STIs) over time. The study has multiple steps: Step 1 follows HIV-negative participants, Step 2 follows those who test positive for HIV during the study, and Step 3 tracks those who achieve viral suppression with treatment. **You may be eligible if...** - You are between 14 and 55 years old - You have a documented negative HIV test - You are considered at increased risk for HIV based on recent STIs, certain sexual behaviors, or injection drug use - You are willing to provide contact information and attend follow-up visits **You may NOT be eligible if...** - You have a significant medical, psychological, or social condition that would interfere with participation - You have active drug or alcohol dependence that would affect your ability to follow study requirements - You have previously participated in an HIV vaccine study (unless you received a placebo) - You are pregnant at the time of screening Talk to your doctor to see if this trial is right for you.