2. Academic Wits University Research Outputs (All submissions)
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Item Cohort Profile: Health and Ageing in Africa: A Longitudinal Study of an INDEPTH Community in South Africa (HAALSI).(2018) F Xavier Go´ mez-Olive´; Livia Montana; Ryan G Wagner; Chodziwadziwa W Kabudula; Julia K Rohr; Kathleen Kahn; Till Ba¨rnighausen; Mark Collinson; David Canning; Thomas Gaziano; Joshua A Salomon; Collin F Payne; Alisha Wad; Stephen M Tollman; Lisa BerkmanItem Genomic and environmental risk factors for cardiometabolic diseases in Africa: methods used for Phase 1 of the AWI-Gen population cross-sectional study(2018-07-12) Stuart A. Al; Cassandra Soo; Godfred Agongo; Marianne Alberts; Lucas Amenga-Etego; Romuald P. Boua; Ananyo Choudhury; Nigel J. Crowther; Cornelius Depuur; F. Xavier GómezOlivé; Issa Guiraud; Tilahun N. Haregu; Scott Hazelhurst; Kathleen Kahn; Christopher Khayeka-Wandabwa; Catherine Kyobutung; Zané Lombard; Felistas Mashinya; Lisa Micklesfield; Shukri F. Mohamed; Freedom Mukomana; Seydou Nakanabo-Diallo; Hamtandi M. Natama; Nicholas Ngomi; Engelbert A. Nonterah; Shane A. Norris; Abraham R. Oduro; Athanase M. Somé; Hermann Sorgho; Paulina Tindana; Halidou Tinto; Stephen Tollman; Rhian Twine; Alisha Wade; Osman Sankoh; Michèle RamsayThere is an alarming tide of cardiovascular and metabolic disease (CMD) sweeping across Africa. This may be a result of an increasingly urbanized lifestyle characterized by the growing consumption of processed and calorie-dense food, combined with physical inactivity and more sedentary behaviour. While the link between lifestyle and public health has been extensively studied in Caucasian and African American populations, few studies have been conducted in Africa. This paper describes the detailed methods for Phase 1 of the AWI-Gen study that were used to capture phenotype data and assess the associated risk factors and end points for CMD in persons over the age of 40 years in sub-Saharan Africa (SSA). We developed a population-based cross-sectional study of disease burden and phenotype in Africans, across six centres in SSA. These centres are in West Africa (Nanoro, Burkina Faso, and Navrongo, Ghana), in East Africa (Nairobi, Kenya) and in South Africa (Agincourt, Dikgale and Soweto). A total of 10,702 individuals between the ages of 40 and 60 years were recruited into the study across the six centres, plus an additional 1021 participants over the age of 60 years from the Agincourt centre. We collected socio-demographic, anthropometric, medical history, diet, physical activity, fat distribution and alcohol/tobacco consumption data from participants. Blood samples were collected for disease-related biomarker assays, and genomic DNA extraction for genome-wide association studies. Urine samples were collected to assess kidney function. The study provides base-line data for the development of a series of cohorts with a second wave of data collection in Phase 2 of the study. These data will provide valuable insights into the genetic and environmental influences on CMD on the African continentItem Hope, the Household Environment, and Sexual Risk Behaviors Among Young Women in Rural South Africa (HPTN 068)(2018-06) Lauren M Hill; Laurie Abler; Suzanne Maman; Rhian Twine; Kathleen Kahn; Catherine MacPhail; Audrey PettiforWe assessed the psychological trait of hope as an explanatory mediator in the relationship between the home environment and sexual risk behaviors among 2533 young women in rural South Africa. Hope mediated the relationship between average household age and sexual debut (mediated effect = −0.003, p<.05), and between household consumption and sexual debut (mediated effect = −0.019, p<.05). Both higher average household age (β = 0.01; 95%CI: 0.00, 0.01) and greater household consumption (β = 0.05; 95%CI: 0.02, 0.08) were marginally associated with higher hope. In turn, greater hope was associated with lower odds of sexual debut (aOR= 0.62; 95%CI: 0.52, 0.74). These results provide important preliminary evidence of the role of the home environment in shaping protective psychological assets and healthy sexual behaviors. Continued exploration of the relationship between hope and the home environment may help to explain why young women in this context have a disproportionate risk for HIV.Item Men’s perspectives on the impact of femaledirected cash transfers on gender relations: Findings from the HPTN 068 qualitative study(2018) Makhosazane Nomhle Khoza; Sinead Delany-Moretlwe; Fiona Scorgie; Jennifer Hove; Amanda Selin; John Imrie; Rhian Twine; Kathleen Kahn; Audrey Pettifor; Catherine MacPhailBackground HIV is an inherently gendered disease in eastern and southern Africa, not only because more women than men are infected, but also because socially constructed gender norms work to increase women’s HIV-infection risk. The provision of cash transfers to young women alone in such a context adds another dimension to already existing complex social relations where patriarchal values are entrenched, gender inequality is the norm, and violence against women and girls is pervasive. It raises concerns about complicating young women’s relationships with their male partners or possibly even setting them up for more violence. In our attempt to understand how cash transfers influence social relations in the context of a trial among young women in South Africa, we used qualitative data collected during the trial to explore men’s perceptions of the impact of cash transfers on male-female relationships, both intimate and platonic, peer relationships. Method Between April 2012 and August 2015, we conducted focus group discussions (n = 12) and interviews (n = 20) with the male peers and intimate partners of young women aged 13–20 years, who were participating in a phase III randomised controlled trial of CTs for HIV prevention in Mpumalanga, South Africa. A thematic content analysis approach was used to analyse the data. The codebook was developed on the basis of the topic guides, with additional codes added inductively as they emerged from the data. Results Intimate partners were older (range 20–32 years) and more likely to be working than the male peers. Both intimate partners and male peers were supportive of the CT trial targeting young women; younger peers however expressed some concerns that the money might diminish their power and status in relationships. HIV testing requirements associated with the trial appeared to have improved communication about sex and HIV in intimate relationships, with some women even encouraging their partners to go for an HIV test. Conclusion CTs provide AGYW with a measure of autonomy and power to contribute in their gendered relationships, albeit in limited ways. However, there is potential for CTs to have a negative impact on male-female relationships if the cash received by AGYW is equal to or greater than the income earned by their male counterparts or sexual partners.Item Transactional sex and incident HIV infection in a cohort of young women from rural South Africa(2018) Kelly Kilburn; Meghna Ranganathan; Marie C.D. Stoner; James P. Hughes; Catherine MacPhail; Yaw Agyei; F. Xavier Gomez-Oliv; Kathleen Kahn; Audrey PettiforObjective: In sub-Saharan Africa, young women who engage in transactional sex (the exchange of sex for money or gifts) with a male partner show an elevated risk of prevalent HIV infection. We analyse longitudinal data to estimate the association between transactional sex and HIV incidence. Design: We used longitudinal data from a cohort of 2362 HIV-negative young women (aged 13–20 years) enrolled in a randomized controlled trial in rural, South Africa who were followed for up to four visits over 6 years. Methods: The effect of transactional sex on incident HIV was analysed using stratified Cox proportional hazards models and cumulative incidence curves. Risk ratios were estimated using log-binomial models to compare the effects across visits. Results: HIV incidence was higher for young women that reported transactional sex (hazard ratio 1.59, 95% confidence interval 1.02–2.19), particularly when money and/ or gifts were received frequently (at least weekly) (hazard ratio 2.71, 95% confidence interval 1.44–5.12). We also find that effects were much stronger during the main trial and dissipate at the postintervention visit, despite an increase in both transactional sex and HIV. Conclusion: Transactional sex elevates the risk of HIV acquisition among young women, especially when it involves frequent exchanges of money and/or gifts. However, the effect was attenuatedafterthe main trial, possibly due to the changing nature oftransactionalsex and sexual partners as women age. These findings suggest that reducing transactional sex among young women, especially during adolescence, is important for HIV prevention.Item Cash transfers for HIV prevention: what do young women spend it on? Mixed methods findings from HPTN 068(2018) Catherine MacPhail; Nomhle Khoza; Amanda Selin; Aimée Julien; Rhian Twine; Ryan G. Wagner; Xavier Goméz-Olivé; Kathy Kahn; Jing Wang; Audrey PettiforBackground Social grants have been found to have an impact on health and wellbeing in multiple settings. Who receives the grant, however, has been the subject of discussion with regards to how the money is spent and who benefits from the grant. Methods Using survey data from 1214 young women who were in the intervention arm and completed at least one annual visit in the HPTN 068 trial, and qualitative interview data from a subset of 38 participants, we examined spending of a cash transfer provided to young women conditioned on school attendance. Results We found that spending was largely determined and controlled by young women themselves and that the cash transfer was predominately spent on toiletries, clothing and school supplies. In interview data, young women discussed the significant role of cash transfers for adolescent identity, specifically with regard to independence from family and status within the peer network. There were almost no negative consequences from receiving the cash transfer. Conclusions We established that providing adolescents access to cash was not reported to be associated with social harms or negative consequences. Rather, spending of the cash facilitated appropriate adolescent developmental behaviors. The findings are encouraging at a time in which there is global interest in addressing the structural drivers of HIV risk, such as poverty, for young women.Item Body composition and physical activity as mediators in the relationship between socioeconomic status and blood pressure in young South African women: a structural equation model analysis(2018-11-11) Richard J Munthali; Mercy Manyema; Rihlat Said-Mohamed; Juliana Kagura; Stephen Tollman; Kathleen Kahn; F Xavier Gómez-Olivé; Lisa K Micklesfield; David Dunger; Shane A NorrisObjectives Varying hypertension prevalence across different socioeconomic strata within a population has been well reported. However, the causal factors and pathways across different settings are less clear, especially in sub-Saharan Africa. Therefore, this study aimed to compare blood pressure (BP) levels and investigate the extent to which socioeconomic status (SES) is associated with BP, in rural and urban South Africa women. Setting Rural and urban South Africa. Design Cross-sectional. Participants Cross-sectional data on SES, total moderate and vigorous physical activity (MVPA), anthropometric and BP were collected on rural (n=509) and urban (n=510) young black women (18–23 years age). Pregnant and mentally or physically disabled women were excluded from the study. Results The prevalence of combined overweight and obesity (46.5% vs 38.8%) and elevated BP (27.0% vs 9.3%) was higher in urban than rural women, respectively. Results from the structural equation modelling showed significant direct positive effects of body mass index (BMI) on systolic BP (SBP) in rural, urban and pooled datasets. Negative direct effects of SES on SBP and positive total effects of SES on SBP were observed in the rural and pooled datasets, respectively. In rural young women, SES had direct positive effects on BMI and was negatively associated with MVPA in urban and pooled analyses. BMI mediated the positive total effects association between SES and SBP in pooled analyses (ß 0.46; 95% CI 0.15 to 0.76). Conclusions Though South Africa is undergoing nutritional and epidemiological transitions, the prevalence of elevated BP still varies between rural and urban young women. The association between SES and SBP varies considerably in economically diverse populations with BMI being the most significant mediator. There is a need to tailor prevention strategies to take into account optimizing BMI when designing strategies to reduce future risk of hypertension in young women. This is an open access article distributed in accordance with the Creative Commons Attribution 4.0 Unported (CC BY 4.0) license, which permits others to copy, redistribute, remix, transform and build upon this work for any purpose, provided the original work is properly cited, a link to the license is given, and indication of whether changes were made.Item ‘It’s because I like things… it’s a status and he buys me airtime’: exploring the role of transactional sex in young women’s consumption patterns in rural South Africa (secondary findings from HPTN 068)(2018) Meghna Ranganathan; Lori Heise; Catherine MacPhail; Heidi Stöckl; Richard J. Silverwood; Kathleen Kahn; Amanda Selin; F. Xavier Gómez-Olivé; Charlotte Watts; Audrey PettiforBackground ‘Transactional sex’, defined as a non-marital, non-commercial sexual relationship in which money or material goods are exchanged for sex, is associated with young women’s increased vulnerability to HIV infection. Existing research illustrates that the motivations for transactional sex are complex. The fulfilment of psycho-social needs such as the need to belong to a peer group are important factors underlying young women’s desires to obtain certain consumption items and thus engage in transactional sex. Methods We use a mixed-methods approach to explore the relationship between transactional sex and consumption patterns among young women in rural Mpumalanga province, South Africa. In the secondary analysis of 693 sexually active young women, we use factor analysis to group the different consumption items and we use multivariable logistic regression to demonstrate the relationship between transactional sex and consumption patterns. The qualitative study uses five focus group discussions and 19 in-depth interviews to explore further young women’s motivations for acquiring different consumption items. Results The quantitative results show that young women that engage in transactional sex have higher odds of consuming items for entertainment (e.g., movie tickets) than on practical items (e.g., food and groceries). The qualitative findings also revealed that young women’s perceptions of items that were considered a ‘need’ were strongly influenced by peer pressure and a desire for improved status. Further, there was a perception that emerged from the qualitative data that relationships with sugar daddies offered a way to acquire consumer goods associated with a ‘modern lifestyle’, such as items for personal enhancement and entertainment. However, young women seem aware of the risks associated with such relationships. More importantly, they also develop relationship with partners of similar age, albeit with the continued expectation of material exchange, despite engaging in the relationship for love. Conclusion This study shows that young women are willing to take certain risks in order to have a degree of financial independence. Interventions that provide alternative methods of attaining this independence, such as the provision of cash transfers may have potential in preventing them from engaging in transactional relationships. Further, the psycho-social reasons that drive young women’s motivations for consumption items resulting in risky sexual behaviours need to be better understood.Item Executive function associated with sexual risk in young South African women: Findings from the HPTN 068 cohort(2018-04-02) Molly Rosenberg; Audrey Pettifor; Mihaela Duta; Nele Demeyere; Ryan G. Wagner; Amanda Selin; Catherine MacPhail; Oliver Laeyendecker; James P. Hughes; Alan Stein; Stephen Tollman; Kathleen KahnPurpose Heightened sexual risk in adolescence and young adulthood may be partially explained by deficits in executive functioning, the set of cognitive processes used to make reasoned decisions. However, the association between executive function and sexual risk is understudied among adolescent girls and young women, particularly in low- and middle-income countries. Methods In a cohort of 853 young women age 18–25 in rural Mpumalanga province, South Africa, we evaluated executive function with three non-verbal cognitive tests: I. a rule-finding test, II. a trail-making test, and III. a figure drawing test. Using log-binomial regression models, we estimated the association between lower executive function test scores and indicators of sexual risk (unprotected sex acts, concurrent partnerships, transactional sex, and recent HSV-2 infection). Results In general, young women with lower executive function scores reported higher frequencies of sexual risk outcomes, though associations tended to be small with wide confidence intervals. Testing in the lowest quintile of Test I was associated with more unprotected sex [aPR (95% CI): 1.4 (1.0, 1.8)]. Testing in the lowest quintile of Test II was associated with more concurrent relationships and transactional sex [aPR (95% CI): 1.6 (1.1, 2.5) and 1.7 (1.3, 2.4), respectively], and testing in the lowest four quintiles of Test III was associated with more concurrent relationships [aPR (95% CI): 1.7 (1.0, 2.7)]. Conclusions These results demonstrate an association between low executive function and sexual risk in South African young women. Future work should seek to understand the nature of this association and whether there is promise in developing interventions to enhance executive function to reduce sexual risk.Item HIV-1 diversity among young women in rural South Africa: HPTN 068(2018-07-05) Mariya V. Sivay; Sarah E. Hudelson; Jing Wang; Yaw Agyei; Erica L. Hamilton; Amanda Selin; Ann Dennis; Kathleen Kahn; F. Xavier Gomez-Olive; Catherine MacPhail; James P. Hughes; Audrey Pettifor; Susan H. Eshleman; Mary Kathryn GrabowskiBackground South Africa has one of the highest rates of HIV-1 (HIV) infection world-wide, with the highest rates among young women. We analyzed the molecular epidemiology and evolutionary history of HIV in young women attending high school in rural South Africa. Methods Samples were obtained from the HPTN 068 randomized controlled trial, which evaluated the effect of cash transfers for school attendance on HIV incidence in women aged 13–20 years (Mpumalanga province, 2011–2015). Plasma samples from HIV-infected participants were analyzed using the ViroSeq HIV-1 Genotyping assay. Phylogenetic analysis was performed using 200 pol gene study sequences and 2,294 subtype C reference sequences from South Africa. Transmission clusters were identified using Cluster Picker and HIV-TRACE, and were characterized using demographic and other epidemiological data. Phylodynamic analyses were performed using the BEAST software. Results The study enrolled 2,533 young women who were followed through their expected high school graduation date (main study); some participants had a post-study assessment (follow-up study). Two-hundred-twelve of 2,533 enrolled young women had HIV infection. HIV pol sequences were obtained for 94% (n = 201/212) of the HIV-infected participants. All but one of the sequences were HIV-1 subtype C; the non-C subtype sequence was excluded from further analysis. Median pairwise genetic distance between the subtype C sequences was 6.4% (IQR: 5.6–7.2). Overall, 26% of study sequences fell into 21 phylogenetic clusters with 2–6 women per cluster. Thirteen (62%) clusters included women who were HIV-infected at enrollment. Clustering was not associated with study arm, demographic or other epidemiological factors. The estimated date of origin of HIV subtype C in the study population was 1958 (95% highest posterior density [HPD]: 1931–1980), and the median estimated substitution rate among study pol sequences was 1.98x10-3 (95% HPD: 1.15x10-3–2.81x10-3) per site per year. Conclusions Phylogenetic analysis suggests that multiple HIV subtype C sublineages circulate among school age girls in South Africa. There were no substantive differences in the molecular epidemiology of HIV between control and intervention arms in the HPTN 068 trial.