The purpose of this study is to collect data and body fluid samples from people with acute or established HIV infection and from HIV uninfected people. Data from this study will be used to better understand properties of HIV, including HIV transmission and the differences between acute and established HIV infections.

Previous studies have identified strategies for the large-scale identification of acute HIV infections. One system using such strategies has already been implemented in North Carolina, and this system will be used in this study run by the Center of HIV/AIDS Vaccine Immunology (CHAVI). This study will collect data on the mechanism of HIV transmission and the genetic, biologic, antigenic, and structural characteristics of the virus. The study will enroll HIV infected people with acute HIV infection and their sexual partners, people with established HIV infection, and HIV uninfected people.

This study will last 96 weeks. Group 1 participants will be people with acute HIV infection. These participants will have 15 study visits; some visits will include a physical exam and medical history. Group 1 will also be asked to complete a sexual behavioral assessment at study entry and every 12 weeks thereafter. Group 2 participants will be people with established HIV infection. Group 3 participants will be HIV uninfected people. Groups 2 and 3 will have 10 study visits; some visits will include a physical exam and medical history. Groups 2 and 3 will also be asked to complete a sexual behavioral assessment at study entry, every 12 weeks until Week 72, and Week 96. Group 3 will undergo HIV testing at each visit and will receive pre- and post-test counseling.

At each visit, participants will undergo HIV safe sex counseling and will update their locator information. Blood, genital secretion, and breast milk collection will also occur at each visit.

Inclusion Criteria for All Participants:

• Willing to receive HIV test results
• Willing to provide updated locator information during the study

Inclusion Criteria for Group 1:

• Acute HIV infection OR sexual partner of a Group 1 participant with acute HIV infection

Inclusion Criteria for Group 2:

• Established HIV infection (positive HIV antibody test and positive HIV Western blot)

Inclusion Criteria for Group 3:

• HIV uninfected

Exclusion Criteria for All Participants:

• Plan to relocate out of the area during the study or have a job or other obligations that may require long absences from the area
• Currently on antiretroviral therapy. Women who previously took antiretroviral therapy for the prevention of mother-to-child transmission of HIV are not excluded.
• Any other condition that, in the opinion of the investigator, may interfere with the study

Up to 1300 with either an acute HIV-1 infection, established HIV-1 infection, or without HIV-1 infection will be enrolled. Sexual partners of those with an acute infection will also be enrolled.