The Pediatric Enhanced Surveillance Study is a three part study of HIV-infected infants and children in South Africa to examine, clinical, immunologic, virologic, metabolic, psychosocial and behavioral outcomes. This study has two parts: (1) comprehensive de-identiﬁed records review of all HIV-infected children enrolled in at the pediatric Wellness and ART clinics at the ﬁve study sites; and (2) a prospective cohort surveillance study with active consented enrollment with 12-24 months of follow-up. As part of the prospective cohort, the study will aim to collect outcomes on children lost to follow-up, including causes of death through review of death certiﬁcates in the clinical chart and through verbal autopsy reports. The study will provide insights into overall outcomes for the larger pediatric patient populations in the province and South Africa. This work is designed in collaboration with the provincial health authorities of the Eastern Cape Department of Health (EC), The International Center for acquired immune deficiency syndrome (AIDS) Care and Treatment Programs (ICAP) South Africa and Center of Disease Control (CDC)-South Africa in support of the South African National ART Program for Children and aims to collect and analyze accurate, relevant and useful information that will be available on children seen at facilities. For the prospective cohort study, we will aim to enroll 400 children newly initiated on ART at 5 health facilities in the Eastern Cape of South Africa who will be actively followed for up to 24 months.