More than 1.5 million deaths of African children under 5 years of age have been due to Plasmodium falciparum malaria. When HIV and malaria are present as coinfections, they enhance each other's progression. The primary purpose of this study is to compare the malarial infection levels in HIV-infected infants and children receiving protease inhibitor (PI)- or non-nucleotide reverse transcriptase inhibitor (NNRTI)-based highly active antiretroviral therapy (HAART).

The World Health Organization (WHO) reports 1 to 2 million malaria deaths annually, with most malaria-related deaths occurring in children. The malaria burden is compounded by the HIV epidemic, which is most prevalent in areas endemic for malaria, notably Sub-Saharan Africa where nine in ten children younger than 15 years of age are infected with HIV. The purpose of this study is to compare parasitemia levels in HIV-infected infants and children receiving PI- or NNRTI-based HAART regimens.

This study will enroll a total of 140 participants, 35 from each of the 4 groups in IMPAACT P1060.

This substudy will last until 24 weeks after the last P1060 enrollment or until P1060 study discontinuation. Participants must meet enrollment criteria for P1060 as well as additional criteria for this study. Study visits will occur as a part of P1060 study visits, all of which include a physical exam, blood collection, and assessments of HIV-related symptoms.

Participants are also encouraged to return to the primary clinic site for intercurrent illness visits for assessment, thick and thin blood smear, and filter paper blood collection, however these visits are not mandatory for study participation.

Inclusion Criteria:

• Enrolling in study IMPAACT P1060
• Parent/legal guardian agrees to seek medical care for intercurrent illness at the study site, whenever possible, and agree to not use at-home remedies for febrile illness in the child

Exclusion Criteria:

None.