As new drugs and vaccines are developed to prevent HIV disease progression and prolong survival of HIV infected patients, the short-term safety and effectiveness of these treatments are evaluated in research studies. However, the long-term effects, whether they are benefits or side effects, need to be studied as well. These long-term effects may have a greater impact on infants and children who are still growing and developing. The purpose of this study is to follow HIV-exposed and HIV infected infants, children, and adolescents who are seen at Pediatric AIDS Clinical Trials Group (PACTG) study sites. These patients will be observed for long-term benefits or any late harmful effects of medications or vaccines.

The potential long-term benefits, toxicities, and other adverse outcomes of new anti-HIV therapies cannot be assessed within the time frame of most clinical trials. There is a need to better assess both positive and negative late outcomes and late treatment effects in growing children. This prospective, longitudinal study will evaluate the effects and their impact on children.

Children in this study will include patients who are HIV infected, were exposed to HIV or anti-HIV drugs prior to or at the time of their birth, or children of patients followed at Pediatric AIDS Clinical Trial Group (PACTG) sites. Children will have a study visit every 3 months through the first year of life. After age 1, children who are HIV infected will continue to have study visits every 3 months, while children who are HIV uninfected will have study visits once a year. Study assessments will include complete physical exam, medical history, Tanner staging, neurologic exam, growth and quality of life assessments, and laboratory tests such as hematology, chemistries, and urinalysis. Not all assessments will be performed at each study visit. Patients will be followed until age 24.

Inclusion Criteria

• Age 21 or younger (consent of parent or guardian required if under 18).
• Meet 1 of the following 3 requirements: 1) enrolled in a previous version of this study; 2) perinatally exposed to HIV, HIV vaccines, or antiretroviral treatment (must enroll before first birthday); 3) HIV infected infants, children, and adolescents (and their offspring) followed at PACTG sites.

Exclusion Criteria

• Unable to adhere to study visit schedules.