Publications by authors named "Bekker L"

Introduction: A vaginal ring containing 25 mg of the antiretroviral dapivirine has demonstrated efficacy in reducing women's risk of sexually acquiring HIV-1; however, imperfect ring use likely diluted efficacy estimates in clinical trials. The amount of dapivirine remaining in returned rings may reflect the extent of product use, permitting estimation of HIV protection in the context of consistent use.

Methods: We measured the amount of dapivirine in returned rings from a placebo-controlled trial of the dapivirine vaginal ring conducted between August 2012 and June 2015 among 2629 African women.

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Background: Young South Africans experience high rates of HIV infection. While nationally scaled medical male circumcision (MMC) can help to curb HIV infection rates in countries such as South Africa (SA), MMC uptake has not been consistent or universal, suggesting variable acceptability among men. Both MMC and traditional male circumcision (TMC) are practised in SA.

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Article Synopsis
  • A long-acting injectable version of rilpivirine (RPV) is being studied for HIV maintenance therapy, with its metabolism after injection not well understood yet.
  • In a phase II trial with 136 HIV-uninfected women, researchers found RPV metabolites in plasma samples, notably 2-hydroxymethyl-RPV and RPV N-glucuronide, detectable in 72 and 78 participants respectively.
  • Genetic analysis revealed various missense and frameshift variants in enzymes linked to RPV metabolism, but these genetic variations did not explain differences in metabolite levels among individuals.
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Background: Health-care resource constraints in low-income and middle-income countries necessitate the identification of cost-effective public health interventions to address COVID-19. We aimed to develop a dynamic COVID-19 microsimulation model to assess clinical and economic outcomes and cost-effectiveness of epidemic control strategies in KwaZulu-Natal province, South Africa.

Methods: We compared different combinations of five public health interventions: health-care testing alone, where diagnostic testing is done only for individuals presenting to health-care centres; contact tracing in households of cases; isolation centres, for cases not requiring hospital admission; mass symptom screening and molecular testing for symptomatic individuals by community health-care workers; and quarantine centres, for household contacts who test negative.

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Young women in sub-Saharan Africa are disproportionally affected by HIV infection and unintended pregnancies. However, hormonal contraceptive (HC) use may influence HIV risk through changes in genital tract microbiota and inflammatory cytokines. To investigate this, 130 HIV negative adolescent females aged 15-19 years were enrolled into a substudy of UChoose, an open-label randomized crossover study (NCT02404038), comparing acceptability and contraceptive product preference as a proxy for HIV prevention delivery methods.

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Background: Pre-exposure prophylaxis (PrEP) with tenofovir disoproxil fumarate and emtricitabine has proven highly effective in preventing HIV acquisition and is therefore offered to all participants in the control group as part of the standard of care package in many new HIV prevention studies. We propose a methodology for predicting HIV incidence in a hypothetical "placebo arm" for open-label studies or clinical trials with active control among African women. We apply the method to an open-label PrEP study, HIV Prevention Trials Network 082, which tested strategies to improve PrEP adherence in young African women all of whom were offered PrEP.

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Background: HIV remains a major public health issue, especially in Eastern and Southern Africa. Pre-exposure prophylaxis is highly effective when adhered to, but its effectiveness is limited by cost, user acceptability and uptake. The cost of a non-inferiority phase III trial is likely to be prohibitive, and thus, it is essential to select the best possible drug, dose and schedule in advance.

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Background: Prioritizing HIV prevention for adolescent girls and young women (AGYW) at high risk for HIV acquisition in sub-Saharan Africa (typically considered ≥3 per 100 person-years [PYs]) is urgently needed, but identifying these AGYW is challenging. We sought to assess and, if needed, enhance a risk assessment tool from the VOICE trial for identifying AGYW at high risk for HIV in Lilongwe, Malawi.

Methods: A multisite prospective cohort study was conducted among sexually active AGYW 15 to 24 years old at 4 health centers in 2016 to 2017.

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Article Synopsis
  • Scientists studied how different vaccines help the body's immune system fight off a bacteria called Mycobacterium tuberculosis, which causes TB.
  • They tested a new vaccine called H4:IC31 and an old one known as BCG to see how well they worked in about 30 people in each group.
  • The study found that H4:IC31 created special T cells that help fight the bacteria, and BCG boosted other immune cells, showing that both vaccines affect how the body responds to infections.
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Introduction: Young women in Southern Africa have extremely high HIV incidence rates necessitating the availability of female-controlled prevention methods. Understanding adolescent preference for seeking contraception would improve our understanding of acceptability, feasibility and adherence to similar modes of delivery for HIV prevention.

Methods: UChoose was an open-label randomized crossover study over 32 weeks which aimed to evaluate the acceptability and preference for contraceptive options in healthy, HIV-uninfected, female adolescents aged 15 to 19 years, as a proxy for similar HIV prevention methods.

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Introduction: Men who have sex with men (MSM) and transgender women (TGW) are at increased risk for acquiring HIV, but there are limited HIV incidence data for these key populations in Africa. Understanding HIV prevalence and incidence provides important context for designing HIV prevention strategies, including pre-exposure prophylaxis (PrEP) programmes. We describe HIV prevalence, awareness of HIV infection, HIV incidence and associated factors for a cohort of MSM and TGW in Cape Town and Port Elizabeth, South Africa.

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Introduction: Men who have sex with men (MSM) and transgender women (TGW) experience high incidence and prevalence of sexually transmitted infections (STI), and data are needed to understand risk factors for STIs in these populations. The Sibanye Health Project was conducted in Cape Town and Port Elizabeth, South Africa from 2015 to 2016 to develop and test a package of HIV prevention interventions for MSM and TGW. We describe the incidence, prevalence and symptoms of Chlamydia trachomatis (CT), Neisseria gonorrhea (NG) and syphilis observed during the study.

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Objectives: Young women in sub-Saharan Africa are at high risk of STIs and unintended pregnancies, yet hormonal contraceptive (HC) use may affect STI risk. We compared the influence of three HCs on the incidence and prevalence of STIs and bacterial vaginosis (BV) in South African adolescents.

Methods: One hundred and thirty adolescents between 15 and 19 years were randomised to the injectable norethisterone enanthate (Net-En), combined oral contraceptives (COC) (Triphasil or Nordette) or a combined contraceptive vaginal ring (CCVR; NuvaRing) for 16 weeks (clinicaltrials.

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Introduction: HIV continues to devastate the adolescent population in sub-Saharan Africa (SSA). The complex array of interpersonal, social, structural and system-level obstacles specific to adolescents have slowed progress in prevention and treatment of HIV in this population. The field of implementation science holds promise for addressing these challenges.

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New HIV infections continue relentlessly in southern Africa, demonstrating the need for a vaccine to prevent HIV subtype C. In South Africa, the country with the highest number of new infections annually, HIV vaccine research has been ongoing since 2003 with collaborative public-private-philanthropic partnerships. So far, 21 clinical trials have been conducted in South Africa, investigating seven viral vectors, three DNA plasmids, four envelope proteins, five adjuvants and three monoclonal antibodies.

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Pregnancy is a high-risk period for HIV acquisition in African women, and pregnant women who become acutely infected with HIV account for up to a third of vertical HIV transmission cases in African settings. To protect women and eliminate vertical transmission, WHO recommends offering oral pre-exposure prophylaxis (PrEP) based on tenofovir to HIV-negative pregnant and post-partum women with a substantial risk of HIV acquisition. PrEP implementation for pregnant and post-partum women lags behind implementation for other high-risk populations.

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Chronic cigarette smokers (CCS) are known to have elevated levels of carboxyhemoglobin (COHb). However, it is not known whether increased levels of COHb are associated with endothelial dysfunction (ED), and therefore the development of peripheral arterial disease (PAD). The aim of the study was to investigate the association of blood COHb and plasma nitric oxide (NO) levels, and whether it is an independent risk factor in the development of PAD among CCS at Dr George Mukhari Academic Hospital (DGMAH).

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Background: Adolescents living with HIV (ALWH) who transition from pediatric to adult care face several challenges that increase their risk of experiencing treatment interruptions and being lost to HIV care with resultant increased morbidity and mortality. To date, few studies have examined their outcomes post-healthcare transition (HCT), precluding the development and dissemination of evidence-based interventions aimed at retaining ALWH in HIV care both during and after HCT. We conducted a systematic review to synthesize the outcomes of ALWH post-HCT to provide suggestions for future directions.

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