Establish and Characterize an Acute HIV Infection Cohort in a High Risk Population

To describe clinical, immunological, and virological characteristics of persons with acute HIV infection 1. To describe demographics and behavioral risk factors for those identified with acute HIV infection 2. To describe neurocognitive function and neuroimaging findings in acute HIV infection as well as describe immune response, HIV-1 genotypes and sequences in the cerebrospinal fluid. 3. To describe the number and characteristics of sexual contacts 4. To describe the willingness of acute HIV-infected subjects to allow the tracking of their sexual contacts for voluntary HIV counseling and testing (VCT) 5. To describe immune response, HIV-1 genotypes and sequences in the genital compartment 6. To describe T cell depletion in the gut mucosa in acute HIV infection and describe the changes in gut T cell during follow up 7. To archive samples for future investigations including determinatio