This study will examine the long-term effects of HIV infection, highly active antiretroviral therapy (HAART), and experimental treatments on children who participated in PACTG 219C or select IMPAACT studies.

The use of HAART has been important in extending the lives of people with HIV infection. However, prolonged use of HAART may have long-term consequences. In addition, people participating in clinical trials using experimental therapies to treat HIV infection may experience negative health outcomes. The purpose of this study is to identify the long-term effects of HIV infection, HAART, and experimental treatments in infants, children, and adolescents.

This study will enroll children who participated in PACTG 219C or various IMPAACT studies. There will be no study visits specifically for this study. Researchers will review participants' medical records annually and collect information on illnesses, medications, CD4 cell count and viral load data, and body measurements.

Inclusion Criteria:

• Past or current documentation of a confirmed diagnosis of HIV-1 infection defined as two separate peripheral blood specimens from different days, and each specimen must be positive. More information on this criterion can be found in the protocol.
• HIV-infected infants, children, or adolescents who participated in PACTG 219C during 5/1/06-5/31/07 and are not currently participating in ongoing long-term follow-up (LTFU) studies (e.g., Pediatric HIV/AIDS Cohort Study Adolescent Master Protocol [PHACS AMP], LEGACY). Please refer to the IMPAACT website for the current list of studies or contact the protocol team (actg.teamp1074@fstrf.org).

OR

• HIV-infected infants, children, and adolescents at domestic sites who have participated in or are currently participating in IMPAACT treatment studies (including studies that have rolled over from the PACTG into IMPAACT) designated by the IMPAACT Network Executive Committee (NEC) for subsequent LTFU in this study, and are not currently participating in ongoing LTFU studies. Please refer to the IMPAACT website for the current list of studies or contact the protocol team (actg.teamp1074@fstrf.org).
• Parent or legally-accepted representative/guardian is able and willing to provide signed informed consent for minors (unless child has emancipated minor status)

Exclusion Criteria:

• Current participation in other ongoing LTFU studies (e.g., PHACS AMP, LEGACY). Please refer to the IMPAACT website for the current list of studies or contact the protocol team (actg.teamp1074@fstrf.org).

The study population will include participants in PACTG 219C or select IMPAACT treatment studies.