The purpose of this study is to see how HIV reacts in the immune systems of patients who have recently been infected with HIV. This study also examines HIV's resistance to anti-HIV drugs in newly infected patients.

Certain populations are good candidates for participation in HIV vaccine trials. These groups include men who have sex with men, IV drug users, and women at risk of getting HIV through heterosexual contact. Learning how HIV behaves in these populations once they become infected can help with the planning of future HIV vaccine studies.

This study provides an opportunity to prospectively monitor markers of HIV infection and disease progression in cohorts suitable for HIV vaccine trials. The detection of changes in HIV phenotype and genotype, clinical progression rates, and antiretroviral resistance within study populations over time are important for planning future HIV vaccine trials.

This study consists of two parts. Part A includes HIV-infected patients who enrolled in HIVNET D01.1 (infected-participants cohort of HIVNET D01) and whose HIV disease has been closely monitored and characterized. This study continues to monitor these patients with follow-up evaluations every 3 months for the first 18 months and then every 6 months thereafter. Part B includes newly HIV-infected patients. These patients are monitored with clinical and laboratory evaluations at 0, 1, 3, 6, 9, 12, and 18 months, and then every 6 months through Year 5.

Inclusion Criteria

Patients must have:

• HIV infection, as documented by enrollment in HIVNET D01.1 (Part A patients) or by standard HIV serological tests or demonstrated HIV infection on virologic assay (Part B patients).

Part A only:

• Previous enrollment in infected-participants cohort of HIVNET D01.

Part B only:

• Initial HIV-seronegativity on an HIVNET protocol (other than an HIV vaccine protocol) and testing positive for HIV at a subsequent clinic visit.
• Confirmation of HIV infection and documentation of HIV negative antibody test within 8 months of first positive test.

Exclusion Criteria

Co-existing Condition:

Patients with the following conditions are excluded:

• An obvious psychological/psychiatric disorder that would invalidate the informed consent process or otherwise contraindicate participation in the study.

Prior Medication:

Excluded:

• Participation in a HIVNET HIV vaccine trial.