HIV-1 incidence and HIV-1-associated mortality in a rural Ugandan population cohort

Abstract

Objective: To determine the incidence of HIV-1 infection and HIV-1-associated mortality in a rural Ugandan population.

Design: A prospective cohort study.

Methods: A cohort consisting of the population (de jure census 9820) of a cluster of 15 villages in Masaka District, south-west Uganda was enrolled between 1989 and 1990 through a demographic and medical survey. The HIV-1 seroprevalence rate was 4.8% for all ages combined and 8.2% for those aged 13 years or more. The survey was repeated after 1 year.

Results: The 1-year HIV-1 incidence rate among adults was 1% [9.2 per 1000 person-years of observation; 95% confidence interval (CI), 5.5-12.9). A total of 84 deaths were observed. In adults, half of all deaths (31 out of 60) were in HIV-1-seropositive individuals. The age-adjusted overall mortality rate ratio for HIV-positive adults compared with HIV-negatives was 20.8 (95% CI, 12.0-35.7). In the 13-44 age group the corresponding rate ratios for men, women and both sexes combined were 16.3, 108.9 and 58.7, respectively. The HIV-attributable mortality fractions, i.e., the proportion of deaths that would have been avoided in the absence of HIV, were 44, 50 and 89% for adult men, adult women and adults aged 25-34 years (both sexes combined), respectively. The 1-year progression to death among HIV-1-seropositive adults was 10.3%.

Conclusion: These results demonstrate the profound impact that the HIV-1 epidemic has on adult mortality in a rural area of Uganda where the HIV-1 prevalence and incidence rates in adults are 8 and 1%, respectively.