Effect of concurrent sexual partnerships on rate of new HIV infections in a high-prevalence, rural South African population: a cohort study

Abstract

SummaryBackgroundConcurrent 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.MethodsFor 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.FindingsDuring 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).InterpretationWe 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.FundingUS National Institute of Child Health and Human Development; Wellcome Trust.

Assessing the Potential Impact of Hormonal-Based Contraceptives on HIV Transmission Dynamics Among Heterosexuals

“…Further, results in [5] showed that the proportion of men reporting that they have had 2 or more sex partners in a year ranged from 1% to 28% in sub-Saharan Africa. In other studies, [74] it was shown that the mean number of lifetime sexual partners ranged from 3.4 to 12.9 with a mean of 6.3 in sexually active men in the region. Mean lifetime number of partners of men in the immediate local community was predictive of hazard of HIV acquisition in women.…”

Setting the Scene: Locations for Meeting Sex Partners Among Behaviorally Bisexual Men in Vientiane, Laos, and Opportunities for Health Promotion

“…Meeting sex partners in hospitality-settings was also associated with a history of having a high number of female partners, and relatively higher number of kathoey partners, which is an important finding given multiple sexual partnerships increase the risk of transmission of HIV and other STIs (Tanser et al, 2011). In contrast, U.S.-based studies have identified associations between meeting sex partners on the Internet and through sex-on-premises venues and reporting a higher number of sex partners (Grov et al, 2013;Horvath et al, 2006;Xia et al, 2006).…”

HIV, logic and sex in Africa

“…But even behavior change interventions targeted at reducing multiple partnering more generally are difficult to bring about; indeed it is unclear that anyone knows how to do this. There is a possibility that messaging targeted specifically on concurrent partnerships could be harmful, by leading to less focus on other forms of multiple partnering, and by negatively impacting on those forms of concurrency which are in fact protective Rosenthal, 2010a, 2010b;Tanser et al, 2011). Further, messaging which implies differences in African sexuality may provoke damaging and even deadly reactions, such as the dissidence of Thabo Mbeki, and therefore must be used with circumspection.…”

“…A widely accepted, relatively recent hypothesis is that a primary driver is a particular model of sexual partnering, referred to as 'multiple concurrent partnerships' or 'concurrency' (Epstein and Halperin, 2007;Epstein and Morris, 2011;Mah and Shelton, 2011). Lively debate about this explanation is ongoing, with serious questions raised as to whether it is supported by evidence Rosenthal, 2010a, 2010b;Padian and Manian, 2011;Sawers and Stillwaggon, 2010;Tanser et al, 2011). We discuss two problems with the concurrency explanation.…”