We conducted a study to measure the efficacy of the then-first line antimalarial drug (sulfadoxine-pyrimethamine) among patients in three study arms: those who were HIV negative, those who were HIV infected with CD4 cell counts < 200, and among HIV infected patients with CD4 cell counts >= 200. Our hypothesis is that patients with HIV infection and low CD4 cell count will not respond to antimalarial therapy as well as patients who are HIV infected with higher CD4 cell counts or who are HIV negative.