Browsing by Author "F. Xavier Gomez-Olive"

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    Built Environment and HIV Linkage to Care in Rural South Africa
    (2023-01) Nosipho Shangase; Brian Pence; Sheri A. Lippman; Mi-Suk Kang Dufour; Chodziwadziwa Whiteson Kabudula; F. Xavier Gomez-Olive; Kathleen Kahn; Audrey Pettifor
    Background: We assessed built environment (residential density, landuse mix and aesthetics) and HIV linkage to care (LTC) among 1,681 (18–49 years-old) residents of 15 Mpumalanga villages, South Africa. Methods: Multilevel models (linear-binomial) were used for the association between built environment, measured using NEWS for Africa, and LTC from a clinical database of 9 facilities (2015–2018). Additionally, we assessed effect-measure modification by universal test-and-treat policy (UTT). Results: We observed, a significant association in the adjusted 3-month probability of LTC for residential density (risk difference (RD)%: 5.6, 95%CI: 1.2–10.1), however, no association for land-use mix (RD%: 2.4, 95%CI: 0.4, 5.2) and aesthetics (RD%: 1.2, 95% CI: 4.5–2.2). Among those diagnosed after UTT, residents of high land-use villages were more likely to link-to-care than those of low land-use villages at 12 months (RD%: 4.6, 95%CI: 1.1–8.1, p < 0.04), however, not at 3 months (RD%: 3.0, 95%CI: 2.1–8.0, p > 0.10). Conclusion: Findings suggest, better built environment conditions (adequate infrastructure, proximity to services etc.) help facilitate LTC. Moreover, UTT appears to have a protective effect on LTC.
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    Developing and evaluating a frailty index for older South Africans—findings from the HAALSI study
    (2021-06-09) Fred J. Barker; Justine I. Davies; F. Xavier Gomez-Olive; Kathleen Kahn; Fiona E. Matthews; Collin F. Payne; Joshua A. Salomon; Stephen M. Tollman; Alisha N.Wade; Richard W.Walker; Miles D.Witham
    Background: despite rapid population ageing, few studies have investigated frailty in older people in sub-Saharan Africa. We tested a cumulative deficit frailty index in a population of older people from rural South Africa. Methods: analysis of cross-sectional data from the Health and Ageing in Africa: Longitudinal Studies of an INDEPTH Community (HAALSI) study. We used self-reported diagnoses, symptoms, activities of daily living, objective physiological indices and blood tests to calculate a 32-variable cumulative deficit frailty index. We fitted Cox proportional hazards models to test associations between frailty category and all-cause mortality. We tested the discriminant ability of the frailty index to predict one-year mortality alone and in addition to age and sex. Results: in total 3,989 participants were included in the analysis, mean age 61 years (standard deviation 13); 2,175 (54.5%) were women. The median frailty index was 0.13 (interquartile range 0.09–0.19); Using population-specific cutoffs, 557 (14.0%) had moderate frailty and 263 (6.6%) had severe frailty. All-cause mortality risk was related to frailty severity independent of age and sex (hazard ratio per 0.01 increase in frailty index: 1.06 [95% confidence interval 1.04–1.07]). The frailty index alone showed moderate discrimination for one-year mortality: c-statistic 0.68–0.76; combining the frailty index with age and sex improved performance (c-statistic 0.77–0.81). Conclusion: frailty measured by cumulative deficits is common and predicts mortality in a rural population of older South Africans. The number of measures needed may limit utility in resource-poor settings.
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    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 Grabowski
    Background 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.
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    The sky is the limit; I am going there”: experiences of hope among young women receiving a conditional cash transfer in rural South Africa
    (2021-05-05) Kaitlyn Atkins; Catherine MacPhail; Suzanne Maman; Nomhle Khoza; Rhian Twine; F. Xavier Gomez-Olive; Audrey Pettifor; Kathleen Kahn
    Young women in South Africa face elevated risk of HIV infection compared to male peers. Cash transfers may mitigate their risk for HIV; however, there is limited understanding of mechanisms of impact. We explored hope as one potential mechanism. Longitudinal qualitative analysis was used to explore how cash transfer recipients in the HPTN 068 study conceptualised hope and how the intervention influenced their hope over time. We found the intervention increased confidence, alleviated financial stressors and instilled in young women the belief that a better life, defined as being educated, independent and supportive to family, was attainable. Findings support hope as a critical outcome of cash transfer and other economic strengthening interventions.