Publications by authors named "John-Stewart G"

Background: Preterm birth (PTB) is a leading cause of neonatal mortality, particularly in sub-Saharan Africa where 40% of global neonatal deaths occur. We identified and combined demographic, clinical, and psychosocial correlates of PTB among Kenyan women to develop a risk score.

Methods: We used data from a prospective study enrolling HIV-negative women from 20 antenatal clinics in Western Kenya (NCT03070600).

View Article and Find Full Text PDF

Background: Most infants born to women living with HIV (WLH) are HIV-exposed but uninfected exposed infants have poorer growth than HIV-unexposed uninfected children. Few large studies have compared children who are exposed (CHEU) and unexposed (CHUU) in the era of dolutegravir (DTG)-based antiretroviral treatment (ART).

Setting: Longitudinal study of mother-infant CHEU and CHUU pairs in Nairobi and Western Kenya.

View Article and Find Full Text PDF

Background: Despite immune restoration after initiation of antiretroviral treatment (ART), the risk of tuberculosis (TB) persists in children living with HIV (CLHIV). We determined patterns of immune restoration of mycobacteria-specific T cells following ART in CLHIV.

Methods: CD4 and CD8 T cell activation and memory phenotype and functional profiles before and 6 months after ART were evaluated in peripheral blood mononuclear cells (PBMCs) from CLHIV enrolled in the PUSH study (NCT02063880) in Nairobi, Kenya.

View Article and Find Full Text PDF

Timely initiation of antiretroviral therapy (ART) remains a major challenge in the effort to treat children living with HIV ("CLH") and little is known regarding the dynamics of immune normalization following ART in CLH with varying times to and durations of ART. Here, we leveraged two cohorts of virally-suppressed CLH from Nairobi, Kenya to examine differences in the peripheral immune systems between two cohorts of age-matched children (to control for immune changes with age): one group which initiated ART during early HIV infection and had been on ART for 5-6 years at evaluation (early, long-term treated; "ELT" cohort), and one group which initiated ART later and had been on ART for approximately 9 months at evaluation (delayed, short-term treated; "DST" cohort). We profiled PBMC and purified NK cells from these two cohorts by mass cytometry time-of-flight (CyTOF).

View Article and Find Full Text PDF

Background: Provision of essential newborn care at home, rapid identification of illness, and care-seeking by caregivers can prevent neonatal mortality. Mobile technology can connect caregivers with information and healthcare worker advice more rapidly and frequently than healthcare visits. Community health workers (CHWs) are well-suited to deliver such interventions.

View Article and Find Full Text PDF

Background: Identifying determinants of longitudinal HIV viral load (VL) trajectories using group-based trajectory modeling (GBTM) can inform clinical strategies and mechanisms of nonadherence among children.

Methods: Children under 12 months old who were newly diagnosed with HIV were enrolled in the Optimizing Pediatric HIV therapy cohort (NCT00428116) from 2007 to 2010. Children initiated antiretroviral therapy at enrollment, and VL was assessed every 3 months for 24 months post-antiretroviral therapy and every 6 months thereafter up to 8 years old.

View Article and Find Full Text PDF

Objectives: Children with HIV may experience adverse neurocognitive outcomes despite antiretroviral therapy (ART). Cytomegalovirus (CMV) is common in children with HIV. Among children on ART, we examined the influences of early HIV viral load and CMV DNA on neurocognition.

View Article and Find Full Text PDF

Pre-exposure prophylaxis (PrEP) is being scaled up to prevent HIV acquisition among adolescent girls and young women (AGYW) in Eastern and Southern Africa. In a prior study more than one-third of AGYW 'mystery shoppers' stated they would not return to care based on interactions with health providers. We examined the experiences of AGYW in this study to identify main barriers to effective PrEP services.

View Article and Find Full Text PDF

Background: Isoniazid preventive therapy (IPT) decreases risk of tuberculosis (TB) disease; impact on long-term infant growth is unknown. In a recent randomized trial (RCT), we assessed IPT effects on infant growth without known TB exposure.

Methods: The infant TB Infection Prevention Study (iTIPS) trial was a non-blinded RCT among HIV-exposed uninfected (HEU) infants in Kenya.

View Article and Find Full Text PDF

Introduction: Children with moderate or severe wasting are at particularly high risk of recurrent or persistent diarrhoea, nutritional deterioration and death following a diarrhoeal episode. Lactoferrin and lysozyme are nutritional supplements that may reduce the risk of recurrent diarrhoeal episodes and accelerate nutritional recovery by treating or preventing underlying enteric infections and/or improving enteric function.

Methods And Analysis: In this factorial, blinded, placebo-controlled randomised trial, we aim to determine the efficacy of lactoferrin and lysozyme supplementation in decreasing diarrhoea incidence and improving nutritional recovery in Kenyan children convalescing from comorbid diarrhoea and wasting.

View Article and Find Full Text PDF

Background: Clinical risk score tools require validation in diverse settings and populations before they are widely implemented. We aimed to externally validate an HIV risk assessment tool for predicting HIV acquisition among pregnant and postpartum women. In the context of prevention of mother-to-child transmission programs, risk score tools could be used to prioritize retesting efforts and delivery of pre-exposure prophylaxis (PrEP) to pregnant and postpartum women most at risk for HIV acquisition while minimizing unnecessary perinatal exposure.

View Article and Find Full Text PDF

Introduction: Pharmacy-delivered HIV prevention services might create more options for pregnant women to use HIV prevention tools earlier and more consistently during pregnancy. We quantified preferences for attributes of potential HIV prevention services among women of childbearing age in Western Kenya.

Methods: From June to November 2023, we administered a face-to-face discrete choice experiment survey to women aged 15-44 in Kenya's Homa Bay, Kisumu and Siaya counties.

View Article and Find Full Text PDF

Introduction: The Data-informed Stepped Care (DiSC) study is a cluster-randomized trial implemented in 24 HIV care clinics in Kenya, aimed at improving retention in care for adolescents and youth living with HIV (AYLHIV). DiSC is a multi-component intervention that assigns AYLHIV to different intensity (steps) of services according to risk. We used the Framework for Reporting Adaptations and Modifications-Expanded (FRAME) to characterize provider-identified adaptations to the implementation of DiSC to optimize uptake and delivery, and determine the influence on implementation outcomes.

View Article and Find Full Text PDF

Background: Studies evaluating the association between the vaginal microbiota and miscarriage have produced variable results.

Objective: This study evaluated the association between periconceptual and first-trimester vaginal microbiota and women's risk for miscarriage.

Methods: At monthly preconception visits and at 9-12 weeks gestation, women collected vaginal swabs for molecular characterisation of the vaginal microbiota.

View Article and Find Full Text PDF

Background: Exclusive breastfeeding (EBF) in the first six months remains low globally, despite known benefits of lower morbidity and mortality among breastfed infants. It is important to understand factors associated with breastfeeding to support optimal breastfeeding practices, particularly in settings with a high burden of HIV.

Methods: We analyzed data from a population-level survey of mother-infant pairs attending 6-week or 9-month immunizations at 141 clinics across Kenya.

View Article and Find Full Text PDF
Article Synopsis
  • Routine HIV viral load testing is crucial for assessing treatment outcomes, but traditional methods face challenges like high costs and slow result delivery.
  • The GeneXpert HIV-1 quantification assay is a potential solution, offering faster and cheaper point-of-care testing, although its real-world effectiveness is still under review.
  • Analysis of 900 samples from studies in Kenya shows that GeneXpert performs well in terms of specificity and agreement with standard testing but has lower sensitivity, indicating that while it could be a reliable monitoring tool, further investigation is needed to ensure accurate results.
View Article and Find Full Text PDF

Objective: To evaluate effectiveness of a standardized patient actor (SP) training intervention to improve quality of preexposure prophylaxis (PrEP) services for adolescent girls and young women (AGYW) in Kenya.

Design: Cluster randomized trial and mystery shopper evaluation.

Methods: Twelve of 24 maternal child health and family planning facilities were randomized to SP training.

View Article and Find Full Text PDF

Purpose: Globally, the number of children/adolescents exposed to HIV but uninfected (HIV-exposed uninfected, HEU) is growing. The HEU outcomes: population-evaluation and screening strategies study was designed to provide population-level evidence of the impact of HIV and recent antiretroviral therapy regimen exposure on neurodevelopmental, hearing and mental health outcomes from infancy to adolescence.

Participants: The study includes a prospective mother-infant cohort and cross-sectional child/youth-caregiver cohorts conducted in Kenya.

View Article and Find Full Text PDF

Escape from cytotoxic T lymphocyte (CTL) responses toward HIV-1 Gag and Nef has been associated with reduced control of HIV-1 replication in adults. However, less is known about CTL-driven immune selection in infants as longitudinal studies of infants are limited. Here, 1,210 and 1,264 sequences longitudinally collected within 15 months after birth from 14 HIV-1 perinatally infected infants and their mothers were analyzed.

View Article and Find Full Text PDF
Article Synopsis
  • - The study measured tenofovir (TFV) concentrations in hair as a way to track adherence to HIV preexposure prophylaxis during pregnancy and after childbirth.
  • - Researchers collected hair samples from 102 women and compared them with dried blood spots (DBSs) to evaluate the effectiveness of this method.
  • - Results showed that having an HIV-positive partner increased hair TFV levels significantly, and there was a strong correlation between hair TFV concentrations and DBS TFV-diphosphate levels, suggesting hair analysis is a reliable adherence indicator.
View Article and Find Full Text PDF

Background: Oral pre-exposure prophylaxis (PrEP) and male partner HIV self-testing (HIVST) is being scaled up within antenatal clinics. Few data are available on how co-distribution influences acceptance of both interventions.

Methods: We used data from the PrEP Implementation of Mothers in Antenatal Care (NCT03070600) trial in Kenya.

View Article and Find Full Text PDF
Article Synopsis
  • Adolescents living with HIV (ALH) in sub-Saharan Africa show lower adherence to antiretroviral therapy (ART) compared to adults, especially in boarding schools where stigma may hinder their treatment.
  • A study conducted in Kenya found that 29% of ALH reported missing their ART doses when school was in session, with those in boarding schools missing doses more frequently than those in day schools.
  • The findings suggest that schools are crucial environments where interventions could improve ART adherence and health outcomes for ALH.
View Article and Find Full Text PDF
Article Synopsis
  • Adolescents with HIV in sub-Saharan Africa struggle with transitioning to adult care, which may hinder their long-term treatment adherence; an adolescent transition package (ATP) aims to address this issue.* -
  • A study in western Kenya estimated the average cost per patient for an HIV care visit and the ATP provision, finding the ATP added an incremental cost of about $3.10 per visit, mainly due to discussions around the ATP booklet.* -
  • The ATP can be effectively implemented in HIV clinics at a manageable cost increase, providing useful data for future economic evaluations and budgeting for adolescent HIV care in Kenya.*
View Article and Find Full Text PDF

Background: Scarce evidence exists on audit and feedback implementation processes in low-resource health systems. The Integrated District Evidence to Action (IDEAs) is a multi-component audit and feedback strategy designed to improve the implementation of maternal and child guidelines in Mozambique. We report IDEAs implementation outcomes.

View Article and Find Full Text PDF

Introduction: Human cathelicidin LL-37 is a salivary antimicrobial peptide (AMP) with broad-spectrum activity against oral diseases, but few studies have assessed its role in children and adolescents living with HIV (CALHIV). We assessed salivary LL-37 levels and correlates in a long-term cohort of Kenyan CALHIV followed since antiretroviral therapy (ART) initiation.

Methods: Saliva was collected from 76 CALHIV who were recruited from two ongoing pediatric HIV studies in Nairobi, Kenya.

View Article and Find Full Text PDF