High HIV-1 incidence in young women masked by stable overall seroprevalence among childbearing women in Kinshasa, Zaïre: estimating incidence from serial seroprevalence data.

OBJECTIVE: To describe the dynamics of the HIV-1 epidemic in childbearing women in Kinshasa, Zaïre, by estimating incidence from serial seroprevalence studies. METHODS: In 1986 and 1989, 5937 and 4623 pregnant women, respectively, were screened for HIV-1 in Kinshasa. We estimated age-specific incidence from two seroprevalence surveys by using a birth-year cohort analysis and adjusting for differences in mortality and fertility between HIV-1-infected and uninfected women. Mortality and fertility data were measured in a cohort of women recruited from the survey in 1986 and followed until 1989. RESULTS: While the overall HIV-1 seroprevalence changed little (5.8% in 1986 and 6.5% in 1989; P = 0.17), the prevalence increased in birth-year cohorts of women under 25 years of age in 1989 from 3.2 to 6.2% (P < 0.001), but decreased for women above 25 years of age from 6.9 to 6.7% (P = 0.7). In addition, new HIV infections between 1986 and 1989 were balanced by a higher mortality and lower fertility observed in HIV-infected women. After adjusting for these effects, we estimated an overall 3-year cumulative HIV-1 incidence of 2.8 per 100 uninfected women [95% confidence interval (CI), 1.4-4.2]. The highest incidence, 5.7 per 100 (95% CI, 3.5-8.0), was in women aged 20-24 years in 1989. CONCLUSION: Despite an overall relatively stable HIV-1 prevalence in childbearing women in Kinshasa between 1986 and 1989, approximately 40% of all HIV-1 infections detected in the 1989 survey occurred between 1986 and 1989, and 60% occurred in women under 25 years of age in 1989.

Lack of association between anti-V3 loop antibody and perinatal HIV-1 transmission in Kinshasa, Zaire, despite use of assays based on local HIV-1 strains.

Maternal antibodies against the V3 loop principal neutralizing domain (PND) have been reported to protect against perinatal HIV-1 transmission. To study this association in an African city with a long-standing HIV epidemic and no established "consensus sequence" for the V3 loop region of gp120, we determined the DNA sequence for the V3 region of HIV-1 from 13 HIV-1-infected residents of Kinshasa, Zaire, and developed peptide enzyme immunoassays (EIAs) reflecting the V3 loop PND for those HIV-1 strains. Using the most broadly reactive locally derived V3 loop peptide in a limited-antigen EIA, there was no significant difference in the perinatal HIV-1 transmission risk between 64 women with anti-V3 loop antibody (transmission risk, 30%) and 104 women without anti-V3 loop antibody (transmission risk, 25%; p = 0.5); this finding was unchanged after we controlled for maternal AIDS and low birth weight. Although we used assays for V3 loop antibody based on local HIV-1 strains and evaluated a large number of mother-child pairs, we found no evidence that maternal anti-V3 loop PND antibody protects against perinatal HIV-1 transmission.

Fertility rates in 238 HIV-1-seropositive women in Zaire followed for 3 years post-partum.

Birth-control use and fertility rates were prospectively determined in 238 HIV-1-seropositive and 315 HIV-1-seronegative women in Kinshasa, Zaire, during the 36-month period following the delivery of their last live-born child. No women delivered children during the first follow-up year. Birth-control utilization rates (percentage use during total observation time) and fertility rates (annual number of live births per 1000 women of child-bearing age) in the second year of follow-up were 19% (107.4 per 1000) for HIV-1-seropositive women and 16% (144.7 per 1000) for HIV-1-seronegative women. In the third year of follow-up these rates were 26 (271.0 per 1000) and 16% (38.6 per 1000) for HIV-1-seropositive and HIV-1-seronegative women, respectively (P less than 0.05 for the difference in birth-control utilization and fertility rates between seropositive and seronegative women in the third year of follow-up). Seven (2.9%) of the 238 HIV-1-seropositive women initially included in the study brought their sex partners in for HIV-1 testing; three (43%) of these men were found to be HIV-1-seropositive. New HIV-1 infection did not have a dramatic effect on the fertility of seropositive women. The nearly uniform unwillingness of HIV-1-seropositive women to inform husbands or sexual partners of their HIV-1 serostatus accounted in large part for the disappointingly high fertility rates in seropositive women who had been provided with a comprehensive program of HIV counseling and birth control. Counseling services for seropositive women of child-bearing age which do not also include these women's sexual partners are unlikely to have an important impact on their high fertility rates.

A retrospective cohort study of the risk of tuberculosis among women of childbearing age with HIV infection in Zaire.

To determine the risk of active tuberculosis associated with HIV infection, we retrospectively studied a cohort of HIV-seropositive and HIV-seronegative women participating in an HIV perinatal transmission study in Kinshasa, Zaire. After a median follow-up of 32 months, new cases of proven pulmonary or clinically diagnosed tuberculosis occurred in 19 of the 249 HIV-seropositive women (7.6%, 3.1 cases per 100 person-years) compared with 1 of the 310 HIV-seronegative women (0.3%, 0.12 cases per 100 person-years), for a relative risk of 26 (95% confidence interval, 5 to 125). Proven pulmonary tuberculosis was diagnosed in 7 HIV-seropositive women (2.8%, 1.2 cases per 100 person-years) and 1 HIV-seronegative woman (0.3%, 0.12 cases per 100 person-years), for a relative risk of 10 (95% confidence interval, 1.5 to 47). We estimated that 66 cases of proven pulmonary tuberculosis in 100,000 person-years of follow-up in women of childbearing age could be attributed to HIV; this is 35% of their estimated total incidence of proven pulmonary tuberculosis. Among those followed for 2 yr, 27 (11%) of 243 HIV-seropositive women died during 2 yr of follow-up compared with none of 296 HIV-seronegative women (p less than 0.001). In HIV-seropositive women with proven or clinically diagnosed tuberculosis mortality was even higher: 5 (26%) of the 19 HIV-seropositive women with proven pulmonary or clinically diagnosed tuberculosis died during follow-up compared with 22 (10%) of the 224 HIV-seropositive women not diagnosed as having tuberculosis (relative risk 2.7; 95% confidence interval, 1.1 to 6.3).(ABSTRACT TRUNCATED AT 250 WORDS)