Africa Centre for Health and Population Studies, University of KwaZulu-Natal, Mtubatuba, South Africa.
Lancet. 2011 Jul 16;378(9787):247-55. doi: 10.1016/S0140-6736(11)60779-4.
Concurrent sexual partnerships are widely believed to be one of the main drivers of the HIV epidemic in sub-Saharan Africa. This view is supported by theoretical models predicting that increases in prevalence of concurrent partnerships could substantially increase the rate of spread of the disease. However, the effect of concurrent partnerships on HIV incidence has not been appropriately tested in a sub-Saharan African setting.
For this population-based cohort study, we used data from the Africa Centre demographic surveillance site in KwaZulu-Natal, South Africa, to try to find support for the concurrency hypothesis. We used a moving-window approach to construct estimates of the geographical variation in reported concurrent and lifetime partners in sexually active men aged 15-55 years (n=2153) across the study area. We then followed up 7284 HIV-negative women (≥15 years of age) in the population and quantified the effect of the sexual behaviour profiles of men in the surrounding local community on a woman's hazard of HIV acquisition.
During 5 years' follow-up, 693 new female HIV infections occurred (incidence 3.60 cases per 100 person-years). We identified substantial intercommunity heterogeneity in the estimated point-prevalence of partnership concurrency (range 4.0-76.3%; mean 31.5%) and mean number of lifetime sexual partners (3.4-12.9; mean 6.3) in sexually active men in this population. After adjustment for individual-level sexual behaviour and demographic, socioeconomic, and environmental factors associated with HIV acquisition, mean lifetime number of partners of men in the immediate local community was predictive of hazard of HIV acquisition in women (adjusted hazard ratio [HR] 1.08, 95% CI 1.03-1.14, p=0.004), whereas a high prevalence of partnership concurrency in the same local community was not associated with any increase in risk of HIV acquisition (adjusted HR 1.02, 95% CI 0.95-1.09, p=0.556).
We find no evidence to suggest that concurrent partnerships are an important driver of HIV incidence in this typical high-prevalence rural African population. Our findings suggest that in similar hyperendemic sub-Saharan African settings, there is a need for straightforward, unambiguous messages aimed at the reduction of multiple partnerships, irrespective of whether those partnerships overlap in time.
US National Institute of Child Health and Human Development; Wellcome Trust.
人们普遍认为，同时性伴侣关系是撒哈拉以南非洲艾滋病毒流行的主要驱动因素之一。这一观点得到了预测流行率增加可能会大大增加疾病传播速度的理论模型的支持。然而，在撒哈拉以南非洲环境中，尚未适当检验同时性伴侣关系对艾滋病毒发病率的影响。
在这项基于人群的队列研究中，我们利用南非夸祖鲁-纳塔尔省非洲中心人口监测点的数据，试图为并发性假设提供支持。我们使用移动窗口方法，构建了研究区域内 15-55 岁有性活动的男性报告的同时性和终身伴侣的地理变化的估计值（n=2153）。然后，我们对人群中 7284 名 HIV 阴性（≥15 岁）的女性进行了随访，并量化了周围社区男性的性行为特征对女性 HIV 感染风险的影响。
在 5 年的随访期间，发生了 693 例新的女性 HIV 感染（发病率为每 100 人年 3.60 例）。我们发现，在该人群中，有性活动的男性中，伴侣同时性的估计点流行率（范围为 4.0-76.3%；平均值为 31.5%）和终生性伴侣的平均数量（3.4-12.9；平均值为 6.3）存在社区间的显著异质性。在调整了与 HIV 感染相关的个体性行为和人口统计学、社会经济和环境因素后，社区内男性的终生性伴侣数量与女性的 HIV 感染风险呈正相关（调整后的危险比[HR]为 1.08，95%置信区间[CI]为 1.03-1.14，p=0.004），而同一社区中高比例的伴侣同时性并不与 HIV 感染风险的增加相关（调整后的 HR 为 1.02，95% CI 为 0.95-1.09，p=0.556）。
我们没有发现证据表明，在这个典型的高流行率农村非洲人群中，同时性伴侣关系是 HIV 发病率的一个重要驱动因素。我们的研究结果表明，在类似的高度流行的撒哈拉以南非洲环境中，需要有简单明了的信息，旨在减少多重伴侣关系，而不论这些伴侣关系是否在时间上重叠。
美国国家儿童健康与人类发展研究所；惠康信托基金会。
