HIV 10: References

Abstract

Department of Epidemiology, School of Hygiene and Public Health, Johns Hopkins University, Baltimore, MD 21205

This study evaluated risk factors associated with prevalent HIV-1 infection among pregnant women in a semi-rural but densely populated area surrounding the town of Butare in Rwanda. Overall seroprevalence was 9.3% in 5690 pregnant women who sought antenatal care at one of five health centres. Factors associated with higher seroprevalence of HIV-1 included history of multiple sexual partners, history of at least one sexually transmitted disease (STD), relatively high socioeconomic status (SES), being unmarried, young age at first pregnancy, and low gravidity. Women who had used oral contraceptives, smoked more than one cigarette per day, whose partners were circumcised, and had had sex to support themselves were also at higher risk of being infected. A history of blood transfusion in the past 5 years was not associated with HIV-1 infection. History of multiple sexual partners, history of STD, high household income, partner circumcision, and past oral contraceptive use remained strongly associated with HIV-1 infection even when simultaneously controlling for other covariates. Among legally married women who lacked sexual behaviour risk factors, history of STD, high SES, young age at first pregnancy, and low gravidity were significantly associated with HIV-1 seroprevalence.

Abstract

African Medical and Research Foundation, Mwanza, Tanzania

OBJECTIVES: To determine baseline HIV prevalence in a trial of improved sexually transmitted disease (STD) treatment, and to investigate risk factors for HIV. To assess comparability of intervention and comparison communities with respect to HIV/STD prevalence and risk factors. To assess adequacy of sample size.

SETTING: Twelve communities in Mwanza Region, Tanzania: one matched pair of roadside communities, four pairs of rural communities, and one pair of island communities. One community from each pair was randomly allocated to receive the STD intervention following the baseline survey.

METHODS: Approximately 1000 adults aged 15-54 years were randomly sampled from each community. Subjects were interviewed, and HIV and syphilis serology performed. Men with a positive leucocyte esterase dipstick test on urine, or reporting a currentSTD, were tested for urethral infections.

RESULTS: A total of 12,534 adults were enrolled. Baseline HIV prevalences were 7.7% (roadside), 3.8% (rural) and 1.8% (islands). Associations were observed with marital status, injections, education, travel, history of STD and syphilis serology. Prevalence was higher in circumcised men, but not significantly after adjusting for confounders. Intervention and comparison communities were similar in the prevalence of HIV (3.8 versus 4.4%), active syphilis (8.7 versus 8.2%), and most recorded risk factors. Within-pair variability in HIV prevalence was close to the value assumed for sample size calculations.

CONCLUSIONS: The trial cohort was successfully established. Comparability of intervention and comparison communities at baseline was confirmed for most factors. Matching appears to have achieved a trial of adequate sample size. The apparent lack of a protective effect of male circumcision contrasts with other studies in Africa.

Abstract

National Institute for Medical Research, Mwanza, Tanzania

OBJECTIVE: To determine the prevalence of HIV-1 infection and to identify the most important risk factors for infection.

DESIGN: A cross-sectional population survey carried out in 1990 and 1991 in Mwanza Region, Tanzania.

METHODS: Adults aged 15-54 years were selected from the region (population, 2 million) by stratified random cluster sampling: 2434 from 20 rural villages, 1157 from 20 roadside settlements and 1554 from 20 urban wards. Risk factor information was obtained from interviews. All sera were tested for HIV-1 antibodies using enzyme-linked immunosorbent assay (ELISA); sera non-negative on ELISA were also tested by Western blot.

RESULTS: The response rate was 81%. HIV-1 infection was 1.5 times more common in women than in men; 2.5% of the adult population in rural villages, 7.3% in roadside settlements and 11.8% in town were infected. HIV-1 infection occurred mostly in women aged 15-34 years and men aged 25-44 years. It was associated with being separated or widowed, multiple sex partners, presence of syphilis antibodies, history of genital discharge or genital ulcer, travel to Mwanza town, and receiving injections during the previous 12 months, but not with male circumcision.

CONCLUSION: This study confirms that HIV-1 infection in this region in East Africa is more common in women than in men. The results are consistent with the spread of HIV-1 infection along the main roads. There is no evidence that lack of circumcision is a risk factor in this population.

Abstract

Institute for Sociology, Free University of Brussels, Belgium

From February to June 1986, 150 heterosexual couples with at least one HIV-seropositive member were recruited in the \'Centre Hospitalier de Kigali\', Kigali, Rwanda. Of the 138 HIV-seropositive couples in whom both members were tested, 124 (90%) were sexual unions between two antibody-positive partners, illustrating the high efficiency of the heterosexual transmission of HIV. A comparison of these 124 couples with 150 HIV-seronegative couples showed that, in the husbands, seropositivity is significantly associated with sexual contacts with prostitutes and history of sexually transmitted disease (STD) within the past 2 years. Seropositive wives were less likely to be in their first marriage and reported more episodes of STD than seronegative ones. Seropositive couples were similar to seronegatives in their history of blood transfusion, male circumcision and overall use of contraception but not in their use of oral contraceptive pills, which was more frequent; they were more often in polygamous unions. Discriminant analysis showed that STD, sexual contacts with prostitutes and the number of previous unions are the most powerful independent variables associated with the seropositivity of the couples. Most of the risk factors for the couples were the risk factors for the husband, suggesting that in most cases the husband acquired the HIV infection and passed it to his wife.