Estimating the seroincidence of HIV-1 in the general adult population in Kigali, Rwanda.

OBJECTIVE

To estimate the seroincidence of HIV-1 infection in the general adult population of Kigali, Rwanda.

DESIGN

Repeated standardized cross-sectional studies.

SETTING

Two urban prenatal clinics.

PATIENTS

A total of 4486 consecutive pregnant women consulting in 1989 and 1990.

MAIN OUTCOME MEASURES

Prevalence of HIV-1 antibodies.

RESULTS

HIV seropositivity increased by 3-5% annually over this period, indicating that it has not reached a plateau in this sentinel population. The percentage infection rates, calculated using two complementary methods, were 26.2-30.7% in 1990. Extrapolating these results to the general population of Kigali, we estimate that 2300-3800 new infections in young women and 3600-6100 new infections in young men occur annually among the total population of 350,000 in Kigali.

CONCLUSIONS

A new HIV infection occurred in an adult every 50-90 min, on average, in Kigali during 1989-1990, while every 6-7 h a baby with maternally acquired HIV infection was born. Our HIV surveillance system, which is based on prenatal sentinel posts, is a useful tool for monitoring the progression of the HIV epidemic in Kigali.