Landon Myer's research while affiliated with University of Cape Town and other places

Publications (565)

Article
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Cisgender women, particularly pregnant and postpartum women in Eastern and Southern Africa, face an unacceptably high risk of HIV acquisition. Oral pre-exposure prophylaxis (PrEP) is an effective HIV prevention intervention that can reduce HIV acquisition and vertical transmission. In this qualitative study, we interviewed 21 postpartum women from...
Article
Background Late initiation of antiretrovirals in pregnancy is associated with increased risk of perinatal transmission and higher infant mortality. We report the final 72-week postpartum results for efficacy and safety of dolutegravir-based compared with efavirenz-based regimens in mothers and infants. Methods DolPHIN-2 was a randomised, open-labe...
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Background Many women in sub-Saharan Africa initiate antenatal care (ANC) late in pregnancy, undermining optimal prevention of mother-to-child-transmission (PMTCT) of HIV. Questions remain about whether and how late initiation of ANC in pregnancy is related to adherence to antiretroviral therapy (ART) in the era of national dolutegravir roll-out....
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Background HIV incidence among pregnant and postpartum women remains high in South Africa. Pre-exposure prophylaxis (PrEP) use remains suboptimal in this population, particularly during the postpartum period when women’s engagement with routine clinic visits outside PrEP decreases. Key barriers to sustained PrEP use include the need for ongoing con...
Article
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Introduction: Women who are pregnant or who could become pregnant experience delayed access to or underinformed use of important new antiretroviral (ARV) drugs because of traditional drug development processes that ostensibly aim to reduce potential harm but effectively fail to ensure that timely information about safe and effective use in pregnan...
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Introduction: Pregnant women are routinely excluded from clinical trials, leading to the absence or delay in even the most basic pharmacokinetic (PK) information needed for dosing in pregnancy. When available, pregnancy PK studies use a small sample size, resulting in limited safety information. We discuss key study design elements that may enhanc...
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Purpose: The Western Cape Pregnancy Exposure Registry (PER) was established at two public sector healthcare sentinel sites in the Western Cape province, South Africa, to provide ongoing surveillance of drug exposures in pregnancy and associations with pregnancy outcomes. Participants: Established in 2016, all women attending their first antenata...
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This study examines baseline associations between alcohol use and HIV sexual risk among a cohort of HIV-uninfected pregnant women (n = 1201) residing in a high HIV burdened community in Cape Town, South Africa. Alcohol use was measured using a modified version of the Alcohol Use Disorder Identification Test (AUDIT). HIV sexual risk was measured thr...
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Background Dolutegravir (DTG)-based regimens have been recommended by the WHO as the preferred first-line and second-line HIV treatment in all populations. Evidence suggests an association with weight gain, particularly among black women. Our study investigated perceptions of weight gain from DTG-based regimen use on body image and adherence of ant...
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Background. Few data are available on COVID-19 outcomes among pregnant women in sub-Saharan Africa (SSA), where high-risk comorbidities are prevalent. We investigated the impact of pregnancy on SARS-CoV-2 infection and of SARS-CoV-2 infection on pregnancy to generate evidence for health policy and clinical practice. Methods. We conducted a 6-countr...
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BACKGROUND: Few data are available on COVID-19 outcomes among pregnant women in sub-Saharan Africa (SSA), where high-risk comorbidities are prevalent. We investigated the impact of pregnancy on SARS-CoV-2 infection and of SARS-CoV-2 infection on pregnancy to generate evidence for health policy and clinical practice. METHODS: We conducted a 6-countr...
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Introduction: Evidence on health-related quality of life (HRQoL) outcomes is limited for new antiretroviral therapies (ART). Dolutegravir-based treatment is being rolled out as the preferred first-line treatment for HIV in many low- and middle-income countries. We compared HRQoL between treatment-naïve pregnant women randomized to dolutegravir- or...
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Background. Few data are available on COVID-19 outcomes among pregnant women in sub-Saharan Africa (SSA), where high-risk co-morbidities are prevalent. We investigated the impact of pregnancy on SARS-CoV-2 infection and of SARS-CoV-2 infection on pregnancy to generate evidence for health policy and clinical practice. Methods. We conducted a 6-count...
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Background In the absence of clinical trials, data on the safety of medicine exposures in pregnancy are dependent on observational studies conducted after the agent has been licensed for use. This requires an accurate history of antenatal medicine use to determine potential risks. Medication use is commonly determined by self-report, clinician reco...
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This study aimed to assess the association of childhood trauma, stressful life events and HIV stigma with mental health in South African adolescents from the Cape Town Adolescent Antiretroviral Cohort (CTAAC). The Childhood Trauma Questionnaire, Life Events Questionnaire and the HIV Stigma Scale for South African Adolescents Living with HIV was use...
Article
Objectives: The role of Klebsiella pneumoniae (KP) in lower respiratory tract infection (LRTI) is not well studied. We longitudinally investigated KP-colonization and the association with LRTI in a South African birth cohort. Methods: We did a case-control study of infants who developed LRTI and age-matched controls, followed two weekly through...
Article
Background: Patients stable on antiretroviral therapy (ART) may require transfer between health care facilities to maintain continuous care yet data on the frequency, predictors and virologic outcomes of transfers are limited. Methods: Data for all viral load (VL) testing at public sector health facilities in the Western Cape Province (2011-2018...
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Background Sexually transmitted infections (STIs) during pregnancy may increase the risk of adverse pregnancy outcomes. STI syndromic management is standard of care in South Africa but has its limitations. We evaluated the impact of diagnosing and treating curable STIs during pregnancy on adverse pregnancy and birth outcomes. Methods We combined d...
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Background Preliminary country-specific reports suggest that the COVID-19 pandemic has a negative impact on the mental health of the healthcare workforce. In this paper, we summarize the protocol of the COVID-19 HEalth caRe wOrkErS (HEROES) study, an ongoing, global initiative, aimed to describe and track longitudinal trajectories of mental health...
Article
Objectives: Tenofovir diphosphate (TFV-DP) in dried blood spots (DBS) is used as a biomarker of ART adherence. Recent treatment studies have shown that TFV-DP predicts future viremia in persons with HIV (PWH) but there are few data from high-burden settings. We investigated whether TFV-DP in DBS predicts future viral breakthrough in South African...
Article
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Introduction: Pre-exposure prophylaxis (PrEP) is a safe and effective prevention strategy to reduce women's risk of HIV in pregnancy and postpartum. Effective PrEP protection requires daily PrEP adherence, but little is known about maternal PrEP continuation and factors that influence PrEP use. Methods: The PrEP in pregnancy and postpartum (PrEP...
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The effect of chronic HIV-infection on psychological adjustment, including the impact of HIV-related stigma in perinatally HIV-infected (PHIV+) youth across Africa is largely unknown. This study examined psychological adjustment and HIV-related stigma using the Strengths and Difficulties Questionnaire (SDQ) and a 10-item stigma questionnaire in a c...
Article
Pregnant and breastfeeding populations are at substantial risk of acquiring HIV in some settings, yet are underrepresented in clinical trials of new pre-exposure prophylaxis (PrEP) agents. Several PrEP formulations are in development (eg, vaginal rings, long-acting injectables, and other modalities). Pregnant and breastfeeding populations are typic...
Article
Rationsale Adherence to antiretroviral therapy (ART) is a global concern among pregnant and postpartum women living with HIV (WLHIV). Research focusing on peripartum WLHIV and how they balance adherence, engaging in HIV care, and other forms of self-care is limited. Women's empowerment theories have been applied to myriad health behaviors to unders...
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Complications from preterm birth are a leading cause of infant mortality, with long-term implications for morbidity and quality of life of preterm infants. There are many important risk factors for preterm births however in this article, we focus on the maternal infection etiological pathway, given its significance in low-to-middle income countries...
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Background Infants born HIV-exposed yet remain uninfected (HEU) are at increased risk of poorer growth and health compared to infants born HIV-unexposed (HU). Whether maternal antiretroviral treatment (ART) in pregnancy ameliorates this risk of poorer growth is not well understood. Furthermore, whether risks are similar across high burden HIV setti...
Article
Background There are few data on the utility of tenofovir diphosphate (TFV-DP) in dried blood spots to predict future viral load (VL) in postpartum women with HIV on antiretroviral therapy (ART). Methods We conducted a nested case-control study within a trial of postpartum ART delivery strategies. Participants started ART containing tenofovir diso...
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Pregnant women in sub-Saharan Africa are at high risk of HIV acquisition and require effective methods to prevent HIV. In a cohort of pregnant women offered Pre-exposure prophylaxis (PrEP), we evaluate the relationship between internalized and anticipated stigma and PrEP initiation at first antenatal visit, 3-month continuation and adherence using...
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Background: Adolescents and youth living with HIV (AYAHIV) have worse HIV outcomes than other age groups, particularly in sub-Saharan Africa (SSA). AYAHIV in SSA face formidable health system, interpersonal- and individual-level barriers to retention in HIV care, uptake of ART, and achievement of viral suppression (VS), underscoring an urgent need...
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Background Pre-exposure prophylaxis (PrEP) is safe and effective in postpartum women. HIV self-testing (HIVST) for male partners combined with biofeedback counselling through real-time adherence measures may improve PrEP use among postpartum women. Methods Between August-2020-April-2021 we randomized postpartum women who initiated PrEP in pregnanc...
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Background: Perinatally acquired HIV-infected (PHIV+) adolescents have shown impairments in neurocognitive function and mental health problems compared with their peers. The contribution of food insecurity to such impairments has not been explored. Objectives: The aim of this report has been to explore the contribution of food insecurity to neuroc...
Article
Background: Antiretroviral therapy (ART) use during pregnancy may be associated with adverse outcomes, but findings have been inconsistent, at least in part due to unreliably estimated gestational age. Objective: To quantify the association between HIV status, ART initiation timing and adverse birth outcomes, with reliably assessed gestational a...
Article
Objective STIs remain a global public health problem with a high burden among pregnant women. STIs in pregnant women may lead to various adverse pregnancy outcomes. In most sub-Saharan African countries, syndromic management is used for screening and treatment of STIs. We aimed to update and summarise pooled prevalence of curable STIs and bacterial...
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Background We compared cost-effectiveness of pediatric provider-initiated HIV testing and counseling (PITC) versus no PITC in a range of clinical care settings in South Africa. Methods We used the CEPAC-Pediatric model to simulate a cohort of children, aged 2-10 years, presenting for care in four settings (outpatient, malnutrition, inpatient, tube...
Article
Background: Maternal HIV and antiretroviral therapy (ART) exposure in utero may influence infant weight, but the contribution of maternal y body mass index (BMI) to early life overweight and obesity is not clear. Objective: To estimate associations between maternal BMI at entry to antenatal care (ANC) and infant weight through approximately 1 ye...
Preprint
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This study examines associations between alcohol use and HIV sexual risk among a cohort of HIV-uninfected pregnant women (n=1201) residing in a high HIV burden community in South Africa. Alcohol use was measured using a modified version of the Alcohol Use Disorder Identification Test (AUDIT). HIV sexual risk was measured through a composite variabl...
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Introduction While pregnant people have been an important focus for HIV research, critical evidence gaps remain regarding prevention, co-infection, and safety and efficacy of new antiretroviral therapies in pregnancy. Such gaps can result in harm: without safety data, drugs used may carry unacceptable risks to the foetus or pregnant person; without...
Article
Background: During pregnancy and postpartum period, the sexual behaviors of women and their partners change in ways that may either increase or reduce HIV risks. Pregnant women are a priority population for reducing both horizontal and vertical HIV transmission. Setting: Nine sites in 4 South African provinces. Methods: Women aged 18-30 years...
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PrEP is safe and effective but requires adherence during potential HIV exposure, yet the facilitators of long-term maternal adherence are not well understood. We conducted semi-structured interviews with 25 postpartum women who reported high adherence (PrEP use ≥ 25 days in last 30-days and never missed a PrEP prescription in pregnancy/postpartum p...
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Objectives: Increased risk of morbidity and hospitalization has been observed in children who are HIV-exposed uninfected (HEU) compared to HIV-unexposed uninfected (HUU). Studies in the era of universal maternal antiretroviral treatment (ART) are limited. Design: Prospective cohort. Methods: We investigated hospitalization between 29 days and...
Article
Background Supporting the ability of women living with HIV (WLWH) to avoid unintended pregnancy during the postpartum period decreases the number of new pediatric HIV infections, reduces pregnancy-related morbidity and mortality, and is a cost-effective strategy for the elimination of mother-to-child transmission. However, little is currently known...
Article
Adverse childhood experiences (ACEs) may have a critical influence on adult outcomes and subsequent offspring development, but few data have explored the effects of ACEs in low-resource settings where the burdens of childhood adversity and HIV are high. Among mothers living with HIV in Cape Town, we examined the effects of ACEs on maternal psychoso...
Article
In settings with a high burden of HIV, pregnant women often experience a cluster of risk factors, including alcohol use and intimate partner violence (IPV). These interrelated risks are poorly understood among pregnant women at risk of HIV in sub-Saharan Africa. We aim to determine cross-sectional associations between pregnant women’s alcohol use a...
Article
Alcohol use, presents unique challenges for HIV-1 treatment in adolescents with perinatally acquired infection. The effects of alcohol on host-virus interaction in the brain and the immune system remains understudied in this population. Adolescents with perinatally acquired HIV infection (PHIV) well established on ART, from the Cape Town Adolescent...
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Purpose Prematurity Immunology in Mothers living with HIV and their infants Study (PIMS) is a prospective cohort study in South Africa investigating the association between antiretroviral therapy (ART) use, preterm delivery (PTD) and small-for-gestational age (SGA) live births. PIMS main hypotheses are that ART initiation in pregnancy and ART-induc...
Article
Introduction: Low vitamin D may increase the risk of tuberculosis; however, previous observational cohort studies have had variable results. We investigated the relationship between vitamin D levels in infancy and subsequent development of tuberculosis throughout childhood. Methods: We enrolled pregnant women between 20-28 weeks' gestation atten...
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Background Although global nutrition/dietary transition resulting from industrialisation and urbanisation has been identified as a major contributor to widespread trends of obesity, there is limited data in pregnant women, including those living with HIV in South Africa. We examined food-based dietary intake in pregnant women with and without HIV a...
Article
Background: Early-life metabolic derangements in HIV-exposed uninfected (HEU) infants have been reported. Methods: Pregnant women with HIV and HIV-uninfected pregnant women were enrolled with their newborns in a US cohort from 2011 to 2015. We measured cord insulin, C-peptide, and metabolic cytokines of HEU and HIV-unexposed uninfected (HUU) new...
Article
Youth living with perinatally acquired HIV (YLPHIV) have been found to have a range of mental disorders. Some adult HIV studies have linked mental health to adverse metabolic outcomes due to dysregulation of the sympathetic nervous system and hypothalamic–pituitary–adrenal axis, but this association has not previously been explored in YLPHIV. We in...
Preprint
Full-text available
Background: Pre-exposure prophylaxis (PrEP) is safe and effective in postpartum women. HIV self-testing (HIVST) for partners combined with biofeedback counselling through real-time adherence measures may improve daily PrEP use among postpartum women. Methods: Between August 2020 and April 2021 we conducted a pilot study in one primary care clinic i...
Preprint
Full-text available
Introduction Oral pre-exposure prophylaxis (PrEP) is a safe and effective prevention strategy to reduce women’s risk of HIV in pregnancy and postpartum. Effective PrEP requires daily PrEP adherence, but little is known about maternal PrEP continuation and risk factors that influence optimal PrEP use. Methods The PrEP in pregnancy and postpartum (P...
Article
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Background Successful scale-up of antiretroviral therapy (ART) during pregnancy has minimized infant HIV acquisition, and over 1 million infants are born HIV-exposed but uninfected (HEU), with an increasing proportion also exposed in utero to maternal ART. While benefits of ART in pregnancy outweigh risks, some studies have reported associations be...
Article
Objectives: Infants who are HIV exposed but uninfected (HEU) compared with HIV unexposed uninfected (HUU) have an increased risk of adverse birth outcomes, morbidity and hospitalization. In the era of universal maternal antiretroviral treatment, there are few insights into patterns of neonatal morbidity specifically. Design: A prospective cohort...
Article
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Early-life vitamin D deficiency is associated with adverse child health outcomes, but the prevalence of vitamin D deficiency and its correlates in infants remains underexplored, particularly in sub-Saharan Africa. We aimed to investigate the prevalence of vitamin D deficiency and its correlates among young infants in South Africa. This study includ...
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Background Adolescents living with HIV (ALHIV) 15-19 years of age are a growing proportion of all people living with HIV globally and the population includes adolescents with vertically acquired HIV (AVH) and behaviorally acquired HIV (ABH).Methods We conducted a survey to measure sociodemographic characteristics, educational status, health history...
Article
Background Implementation of universal antiretroviral therapy (ART) has significantly lowered vertical transmission rates but has also increased numbers of HIV-exposed uninfected children (HEU), who remain vulnerable to morbidities. Here, we investigated whether T cell alterations in the placenta contribute to altered immune status in HEU. Methods...
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Introduction There are limited data on Tuberculosis (TB) in adolescents with perinatally acquired HIV (APHIV). We examined the incidence and determinants of TB infection and disease in the Cape Town Adolescent Antiretroviral Cohort (CTAAC). Methods Youth between nine and fourteen years on antiretroviral therapy (ART) for more than six months in pu...
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Background Maternal depression is an important cause of morbidity and mortality. Experiences of childhood trauma contribute to maternal depression, potentially causing adult socio-economic disparities in mental health. We investigate whether adult socioeconomic status (SES) mediates the relationship between childhood trauma and antenatal depression...
Article
Objective To examine associations between high blood pressure (BP) when entering antenatal care (ANC) and birth outcomes in a cohort of pregnant HIV- and women living with HIV (WLHIV) initiating antiretroviral treatment (ART). Study Design Prospective cohort study. Main Outcome Measures Cesarean delivery, preterm birth (<37 weeks’ gestation), low...
Article
HIV-associated functional impairment may cause cognitive impairment secondary to the viral infection, hence, associations between cognitive impairment and functional impairment in youth living with HIV are important to assess. We sought to determine whether cognitive impairment is associated with functional impairment and if it carries higher risk...
Article
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Background: Mechanisms underlying an association between HIV or antiretroviral therapy (ART) during pregnancy with risk of preterm delivery (PTD) and small-for-gestational-age (SGA) remain unclear. We explored the association between cellular immune activation and PTD or SGA in HIV-infected women initiating ART during or before pregnancy. Methods...
Article
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Background: Discharge diagnostic data from hospital administrative databases are often used to inform decisions relating to a variety of vital applications. These may include the allocation of resources, quality-of-care assessments, clinical research and formulation of healthcare policy. Accurately coded and reliably captured patient discharge data...
Article
Objective: We examined the longitudinal association between women's exposure to intimate partner violence (IPV) and HIV viral load (VL) during pregnancy and postpartum. Design: Secondary analysis of an HIV-positive cohort enrolled during pregnancy at a South African antenatal clinic. Methods: VL was assessed at ten study visits and analyzed co...
Article
We recently demonstrated that adolescents perinatally infected with HIV-1 (PHIV+) have accelerated aging as measured by a highly accurate epigenetic biomarker of aging known as the epigenetic clock. However, whether epigenetic age acceleration in PHIV+ impacts brain development at the macro- and microstructural levels of brain anatomy has not been...