HIV-1 DISEASE PROGRESSION AND AIDS-DEFINING DISORDERS IN RURAL UGANDA

Background The majority of people infected with HIV-1 live in Africa, yet little is known about the natural history of the disease in that c ontinent. We studied survival times, disease progression, and AIDS-def ining disorders, according to the proposed WHO staging system, in a po pulation-based, rural cohort in Uganda. Methods In 1990 we recruited a random sample of people already infected with HIV-1 (as prevalent cas es) detected during the initial survey round of a general-population s tudy to form a natural-history cohort. Individuals from the general-po pulation cohort who seroconverted between 1990 and 1995 (incident case s) were also invited to enrol. Participants were seen routinely every 3 months and when they were ill. Findings By the end of 1995, 93 preva lent cases and 86 incident cases had been enrolled. Four patients in t he prevalent group were in stage 4 (AIDS) at the initial visit. During the next 5 years, 37 prevalent cases progressed to AIDS. Seven incide nt cases progressed to AIDS and the cumulative progression to AIDS at 1, 3, and 5 years after seroconversion was 2%, 6%, and 22%, respective ly. The cumulative probability of AIDS at 4 years from entering stages 1, 2, and 3 was 11%, 33%, and 58%, respectively. There were 47 deaths among prevalent cases and seven among incident cases during follow-up . The cumulative mortality 4 years after patients entered stages 1, 2, 3, and 4 was 9%, 33%, 56%, and 86%, respectively. The median survival after the onset of AIDS was 9.3 months. Interpretation Our results ar e important for the setting of priorities and rationalisation of treat ment availability in countries with poor resources. We found that prog ression rates to AIDS are similar to those in developed countries for homosexual cohorts and greater than for cohorts infected by other mode s of transmission. However, we have found that the rates of all-cause mortality are much higher and the progression times to death are short er than in developed countries.