Heterosexual transmission of HIV-1 among employees and their spouses at two large businesses in Zaire

Abstract

To better understand the reasons why up to 80% of all HIV-1 infections in Zaire, but < 5% in North America and Europe, are acquired through heterosexual transmission, and to assess the impact of HIV-1 infection on a large urban African workforce, we enrolled 7068 male employees, 416 female employees and 4548 female spouses of employees at two large Kinshasa businesses (a textile factory and a commercial bank) in a prospective study of HIV-1 infection. The HIV-1 seroprevalence rate was higher in male employees (5.8%) and their spouses (5.7%) at the bank than among male employees (2.8%) and their spouses (3.3%) at the textile factory. At both businesses HIV-1 seroprevalence was higher among employees in managerial positions (5.0%) than among workers in lower-level positions (3.0%; P < 0.0001). In a multivariate analysis of male employees, receipt of a transfusion, a history of genital ulcer disease, working at the bank, urethritis, or being divorced or separated were independently associated with HIV-1 infection. During 1987 and 1988, AIDS was the most common cause of death among recently employed workers, accounting for 20 and 24% of all deaths at the textile factory and the commercial bank, respectively. The HIV-1 seroprevalence rate was higher among female workers (7.7%) than among the spouses of male workers (3.9%; P = 0.001). In multivariate analysis of the wives of workers, having an HIV-1-seropositive spouse, receipt of a blood transfusion, or a history of genital ulcer disease were independently associated with HIV-1 infection. HIV-1 infection was found in 239 (5.3%) of the 4487 married couples in the study. In 85% of these infected couples, only one member was HIV-1-seropositive despite repeated unprotected sex. We conclude that heterosexual promiscuity and the resultant increased risk of acquiring a sexually transmitted disease has played an important role in promoting HIV-1 transmission in this large Kinshasa population.