The prevalence of infection with human immunodeficiency virus over a 10-year period in rural Zaire.

In 1985 we tested 659 human serum samples, collected in the remote Equateur province of Zaire in 1976, for antibody to human immunodeficiency virus (HIV). Five (0.8 percent) were positive, and HIV was isolated from one of these. Follow-up investigations in 1985 revealed that three of the five seropositive persons had died of illnesses suggestive of acquired immunodeficiency syndrome (AIDS), and two remained healthy but seropositive. In 1986, a serosurvey we conducted using a cluster-sampling technique in the same region showed a seroprevalence of 0.8 percent in 389 randomly selected residents. The seroprevalence in 283 prostitutes was 11 percent. Patients with AIDS were identified in various hospitals in the province. Risk factors for AIDS included a greater than average number of sexual partners and residence outside the area. We believe that the long-term stability of HIV infection in residents of rural Zaire suggests that social change may have promoted the spread of AIDS in Africa.