Risk of developing AIDS after primary acute HIV-1 infection.

We enrolled 134 newly human immunodeficiency virus type 1 (HIV-1)-infected subjects in a prospective study to determine the natural history of the infection and evaluate the risk of developing AIDS after acute primary HIV-1 infection (API). Twenty-three patients were observed during an acute primary HIV-1 infection, and 111 were asymptomatic seroconverters. Acute primary HIV-1 infection was more frequently observed in subjects who had acquired the infection through sexual transmission. Intravenous drug users were rarely affected and presented with milder symptomatology. Patients observed with an acute primary HIV-1 infection had a significantly higher risk of developing AIDS than asymptomatic seroconverters (68% at 56 months vs. 20% at 66 months; p = 0.026). Low CD4+ cell counts at the onset of acute illness and delayed seroconversion in enzyme-linked immunosorbent assay (ELISA) were associated with evolution to AIDS in acute seroconverters (p = 0.03 and 0.02, respectively). During the follow-up, patients with an acute illness were more likely to show an early fall of CD4+ cell counts below 200/microliters than asymptomatic seroconverters. The results of this follow-up study suggest the opportunity to study antiviral treatment protocols in patients with API as a possible measure to control disease progression.