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result(s) for
"Chasekwa, Bernard"
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The gut microbiome and early-life growth in a population with high prevalence of stunting
2023
Stunting affects one-in-five children globally and is associated with greater infectious morbidity, mortality and neurodevelopmental deficits. Recent evidence suggests that the early-life gut microbiome affects child growth through immune, metabolic and endocrine pathways. Using whole metagenomic sequencing, we map the assembly of the gut microbiome in 335 children from rural Zimbabwe from 1–18 months of age who were enrolled in the Sanitation, Hygiene, Infant Nutrition Efficacy Trial (SHINE; NCT01824940), a randomized trial of improved water, sanitation and hygiene (WASH) and infant and young child feeding (IYCF). Here, we show that the early-life gut microbiome undergoes programmed assembly that is unresponsive to the randomized interventions intended to improve linear growth. However, maternal HIV infection is associated with over-diversification and over-maturity of the early-life gut microbiome in their uninfected children, in addition to reduced abundance of
Bifidobacterium
species. Using machine learning models (XGBoost), we show that taxonomic microbiome features are poorly predictive of child growth, however functional metagenomic features, particularly B-vitamin and nucleotide biosynthesis pathways, moderately predict both attained linear and ponderal growth and growth velocity. New approaches targeting the gut microbiome in early childhood may complement efforts to combat child undernutrition.
Here, using metagenomics, the authors show that the gut microbiome of rural Zimbabwean infants undergoes programmed maturation that is unresponsive to sanitation and nutrition interventions but is strongly associated with maternal HIV infection and can moderately predict linear growth.
Journal Article
Stunting Is Characterized by Chronic Inflammation in Zimbabwean Infants
2014
Stunting affects one-third of children in developing countries, but the causes remain unclear. We hypothesized that enteropathy leads to low-grade inflammation, which suppresses the growth hormone-IGF axis and mediates stunting.
We conducted a case-control study of 202 HIV-unexposed Zimbabwean infants who were stunted (height-for-age Z-score (HAZ) <-2; cases) or non-stunted (HAZ >-0.5; controls) at 18 months. We measured biomarkers of intestinal damage (I-FABP), inflammation (CRP, AGP, IL-6) and growth hormone-IGF axis (IGF-1, IGFBP3) in infant plasma at 6 weeks and 3, 6, 12 and 18 months, and in paired maternal-infant plasma at birth. Adjusted mean differences between biomarkers were estimated using regression models. Multivariate odds ratios of stunting were estimated by logistic regression.
At birth, cases were shorter (median (IQR) HAZ -1.00 (-1.53, -0.08) vs 0.03 (-0.57, 0.62,); P<0.001) than controls and their mothers had lower levels of IGF-1 (adjusted mean difference (95%CI) -21.4 (-39.8, -3.1) ng/mL). From 6 weeks to 12 months of age, levels of CRP and AGP were consistently higher and IGF-1 and IGFBP3 lower in cases versus controls; IGF-1 correlated inversely with inflammatory markers at all time-points. I-FABP increased between 3-12 months, indicating extensive intestinal damage during infancy, which was similar in cases and controls. In multivariate analysis, higher log10 levels of CRP (aOR 3.06 (95%CI 1.34, 6.99); P = 0.008) and AGP (aOR 7.87 (95%CI 0.74, 83.74); P = 0.087) during infancy were associated with stunting. There were no associations between levels of I-FABP, IL-6, sCD14 or EndoCAb and stunting.
Stunting began in utero and was associated with low maternal IGF-1 levels at birth. Inflammatory markers were higher in cases than controls from 6 weeks of age and were associated with lower levels of IGF-1 throughout infancy. Higher levels of CRP and AGP during infancy were associated with stunting. These findings suggest that an extensive enteropathy occurs during infancy and that low-grade chronic inflammation may impair infant growth.
Journal Article
Associations between maternal obesity and infectious morbidity in Zimbabwean infants
by
Greenland, Katie
,
Humphrey, Jean H
,
Chasekwa Bernard
in
Body mass index
,
Body size
,
Body weight
2022
The prevalence of overweight and obesity is increasing among reproductive-age women in sub-Saharan Africa. Whether maternal body mass index (BMI) influences the risk of infant infections in low- and middle-income countries (LMIC) is uncertain. We used data from a birth cohort of 5344 HIV-unexposed Zimbabwean infants with available data on maternal BMI, to calculate rates of sick clinic visits for infections during the first 12 months postpartum, and adjusted hazard ratios (aHR) for each maternal BMI group. Compared to infants of mothers with normal BMI, the rate of sick clinic visits for any infection progressively rose among infants of overweight (aHR 1.05; 95%CI 0.99, 1.11) and obese women (aHR 1.15; 95%CI 1.05, 1.25). Excess clinic attendances were particularly due to skin, respiratory and ear infections. Maternal obesity may therefore influence infant infectious morbidity in LMIC over the first year after birth.
Journal Article
Inflammation and cytomegalovirus viremia during pregnancy drive sex-differentiated differences in mortality and immune development in HIV-exposed infants
2024
Children who are HIV-exposed but uninfected have increased infectious mortality compared to HIV-unexposed children, raising the possibility of immune abnormalities following exposure to maternal viraemia, immune dysfunction, and co-infections during pregnancy. In a secondary analysis of the SHINE trial in rural Zimbabwe we explored biological pathways underlying infant mortality, and maternal factors shaping immune development in HIV-exposed uninfected infants. Maternal inflammation and cytomegalovirus viraemia were independently associated with infant deaths: mortality doubled for each log
10
rise in maternal C-reactive protein (adjusted hazard ratio (aHR) 2.09; 95% CI 1.33–3.27), and increased 1.6-fold for each log
10
rise in maternal cytomegalovirus viral load (aHR 1.62; 95% CI 1.11–2.36). In girls, mortality was more strongly associated with maternal C-reactive protein than cytomegalovirus; in boys, mortality was more strongly associated with cytomegalovirus than C-reactive protein. At age one month, HIV-exposed uninfected infants had a distinct immune milieu, characterised by raised soluble CD14 and an altered CD8 + T-cell compartment. Alterations in immunophenotype and systemic inflammation were generally greater in boys than girls. Collectively, these findings show how the pregnancy immune environment in women with HIV underlies mortality and immune development in their offspring in a sex-differentiated manner, and highlights potential new intervention strategies to transform outcomes of HIV-exposed children. ClinicalTrials.gov/NCT01824940.
HIV exposed but uninfected infants may face an increased risk of serious infection and mortality. In this work, the authors utilise a cohort from rural Zimbabwe to explore the biological mechanisms underlying infant mortality.
Journal Article
Stunting Status and Exposure to Infection and Inflammation in Early Life Shape Antibacterial Immune Cell Function Among Zimbabwean Children
by
Govha, Margaret
,
Mushayanembwa, Patience
,
Matimba, Farai S.
in
Anthropometry
,
Asymptomatic
,
Babies
2022
BackgroundChildren who are stunted (length-for-age Z-score<-2) are at greater risk of infectious morbidity and mortality. Previous studies suggest that stunted children have elevated inflammatory biomarkers, but no studies have characterised their capacity to respond to new infections (i.e., their immune function). We hypothesised that antibacterial immune function would differ between stunted and non-stunted children and relate to their health and environment during early life.MethodsWe enrolled a cross-sectional cohort of 113 HIV-negative children nested within a longitudinal cluster-randomised controlled trial of household-level infant and young child feeding (IYCF) and water, sanitation and hygiene (WASH) interventions in rural Zimbabwe (SHINE; Clinical trials registration: NCT01824940). Venous blood was collected at 18 months of age and cultured for 24 h without antigen or with bacterial antigens: heat-killed Salmonella typhimurium (HKST) or Escherichia coli lipopolysaccharide (LPS). TNFα, IL-6, IL-8, IL-12p70, hepcidin, soluble (s)CD163, myeloperoxidase (MPO) and IFNβ were quantified in culture supernatants by ELISA to determine antigen-specific immune function. The effect of stunting status and early-life exposures (anthropometry, inflammation at 18 months, maternal health during pregnancy, household WASH) on immune function was tested in logit and censored log-normal (tobit) regression models.ResultsChildren who were stunted (n = 44) had higher proportions (86.4% vs. 65.2%; 88.6% vs . 73.4%) and concentrations of LPS-specific IL-6 (geometric mean difference (95% CI): 3.46 pg/mL (1.09, 10.80), p = 0.035) and IL-8 (3.52 pg/mL (1.20, 10.38), p = 0.022) than non-stunted children (n = 69). Bacterial antigen-specific pro-inflammatory cytokine concentrations were associated with biomarkers of child enteropathy at 18 months and biomarkers of systemic inflammation and enteropathy in their mothers during pregnancy. Children exposed to the WASH intervention (n = 33) produced higher LPS- (GMD (95% CI): 10.48 pg/mL (1.84, 60.31), p = 0.008) and HKST-specific MPO (5.10 pg/mL (1.77, 14.88), p = 0.003) than children in the no WASH group (n = 80). There was no difference in antigen-specific immune function between the IYCF (n = 55) and no IYCF groups (n = 58).ConclusionsAntibacterial immune function among 18-month-old children in a low-income setting was shaped by their stunting status and prior exposure to maternal inflammation and household WASH. Heterogeneity in immune function due to adverse exposures in early life could plausibly contribute to infection susceptibility.
Journal Article
Performance of the UNICEF/UN Washington Group tool for identifying functional difficulty in rural Zimbabwean children
by
Chasekwa, Bernard
,
Majo, Florence
,
Mutasa, Batsirai
in
Biology and Life Sciences
,
Child
,
Child development
2022
Over one billion people live with disability worldwide, of whom 80% are in developing countries. Robust childhood disability data are limited, particularly as tools for identifying disability function poorly at young ages.
A subgroup of children enrolled in the Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial (a cluster-randomised, community-based, 2x2 factorial trial in two rural districts in Zimbabwe) had neurodevelopmental assessments at 2 years of age. We evaluated functional difficulty prevalence in HIV-exposed and HIV-unexposed children using the Washington Group Child Functioning Module (WGCFM), comparing absolute difference using chi-squared or Fisher's exact tests. Concurrent validity with the Malawi Developmental Assessment Tool (MDAT) was assessed using logistic regression with cohort MDAT score quartiles, linear regression for unit-increase in raw scores and a Generalised Estimating Equation approach (to adjust for clusters) to compare MDAT scores of those with and without functional difficulty. A 3-step, cluster-adjusted multivariable regression model was then carried out to examine risk factors for functional difficulty.
Functional Difficulty prevalence was 4.2% (95%CI: 3.2%, 5.2%) in HIV-unexposed children (n = 1606) versus 6.1% (95%CI: 3.5%, 8.9%) in HIV-exposed children (n = 314) (absolute difference 1.9%, 95%CI: -0.93%, 4.69%; p = 0.14). Functional difficulty score correlated negatively with MDAT: for each unit increase in WGCFM score, children completed 2.6 (95%CI: 2.2, 3.1) fewer MDAT items (p = 0.001). Children from families with food insecurity and poorer housing were more at risk of functional difficulty.
Functional difficulty was identified in approximately 1-in-20 children in rural Zimbabwe, which is comparable to prevalence in previous studies. WGCFM showed concurrent validity with the MDAT, supporting its use in early childhood.
Journal Article
Measuring wealth in rural communities: Lessons from the Sanitation, Hygiene, Infant Nutrition Efficacy (SHINE) trial
by
Martin, Stephanie L.
,
Wu, Fan
,
Tielsch, James M.
in
Agricultural economics
,
Agricultural resources
,
Biology and Life Sciences
2018
Poverty and human capital development are inextricably linked and therefore research on human capital typically incorporates measures of economic well-being. In the context of randomized trials of health interventions, for example, such measures are used to: 1) assess baseline balance; 2) estimate covariate-adjusted analyses; and 3) conduct subgroup analyses. Many factors characterize economic well-being, however, and analysts often generate summary measures such as indices of household socio-economic status or wealth. In this paper, a household wealth index is developed and tested for participants in the cluster-randomized Sanitation, Hygiene, Infant Nutrition Efficacy (SHINE) trial in rural Zimbabwe.
Building on the approach used in the Zimbabwe Demographic and Health Survey (ZDHS), we combined a set of housing characteristics, ownership of assets and agricultural resources into a wealth index using principal component analysis (PCA) on binary variables. The index was assessed for internal and external validity. Its sensitivity was examined considering an expanded set of variables and an alternative statistical approach of polychoric PCA. Correlation between indices was determined using the Spearman's rank correlation coefficient and agreement between quintiles using a linear weighted Kappa statistic. Using the 2015 ZDHS data, we constructed a separate index and applied the loadings resulting from that analysis to the SHINE study population, to compare the wealth distribution in the SHINE study with rural Zimbabwe.
The derived indices using the different methods were highly correlated (r>0.9), and the wealth quintiles derived from the different indices had substantial to near perfect agreement (linear weighted Kappa>0.7). The indices were strongly associated with a range of assets and other wealth measures, indicating both internal and external validity. Households in SHINE were modestly wealthier than the overall population of households in rural Zimbabwe.
The SHINE wealth index developed here is a valid and robust measure of wealth in the sample.
Journal Article
The Impact of Improved Water, Sanitation, and Hygiene on Oral Rotavirus Vaccine Immunogenicity in Zimbabwean Infants
by
Carmolli, Marya P.
,
Church, James A.
,
Govha, Margaret
in
and Commentaries
,
ARTICLES AND COMMENTARIES
,
Female
2019
Abstract
Background
Oral vaccines have lower efficacy in developing compared to developed countries. Poor water, sanitation, and hygiene (WASH) may contribute to reduced oral vaccine immunogenicity.
Methods
We conducted a cluster-randomized 2 × 2 factorial trial in rural Zimbabwe. Pregnant women and their infants were eligible if they lived in clusters randomized to (1) standard of care (52 clusters); (2) improved infant feeding (53 clusters); (3) WASH: ventilated improved pit latrine, 2 hand-washing stations, liquid soap, chlorine, infant play space, and hygiene counseling (53 clusters); or (4) feeding plus WASH (53 clusters). This substudy compared oral rotavirus vaccine (RVV) seroconversion (primary outcome), and seropositivity and geometric mean titer (GMT) (secondary outcomes), in WASH vs non-WASH infants by intention-to-treat analysis.
Results
We included 801 infants with documented RVV receipt and postvaccine titer measurements (329 from 84 WASH clusters; 472 from 102 non-WASH clusters); 328 infants with prevaccination titers were included in the primary outcome. Thirty-three of 109 (30.3%) infants in the WASH group seroconverted following rotavirus vaccination, compared to 43 of 219 (19.6%) in the non-WASH group (absolute difference, 10.6% [95% confidence interval {CI}, .54%–20.7%]; P = .031). In the WASH vs non-WASH groups, 90 of 329 (27.4%) vs 107 of 472 (22.7%) were seropositive postvaccination (absolute difference, 4.7% [95% CI, –1.4% to 10.8%]; P = .130), and antirotavirus GMT was 18.4 (95% CI, 15.6–21.7) U/mL vs 14.9 (95% CI, 13.2–16.8) U/mL (P = .072).
Conclusions
Improvements in household WASH led to modest but significant increases in seroconversion to RVV in rural Zimbabwean infants.
Clinical Trials Registration
NCT01824940.
Oral vaccines have lower efficacy in developing compared to developed countries. In a substudy of a cluster-randomized trial, improvements in household water, sanitation, and hygiene led to modest increases in seroconversion to oral rotavirus vaccine among rural Zimbabwean infants.
Journal Article
Child play and caregiver support to promote convalescence following severe acute malnutrition in Zimbabwe: The Tamba‐SAM pilot study
2025
Children hospitalised for severe acute malnutrition (SAM) have a high risk of mortality, relapse and rehospitalisation following hospital discharge. Current approaches fail to promote convalescence, or to address the underlying social determinants of SAM, meaning that restoration of long‐term health, growth and neurodevelopment is not achieved. Although guidelines recommend play and stimulation to promote recovery, most caregivers are not supported to do this at home. We set out to evaluate the feasibility and acceptability of a codesigned intervention package aimed at providing child stimulation through play, and strengthening caregiver capabilities through problem‐solving skills, peer support and income‐generating activities. We evaluated the intervention in two phases, enroling 30 caregiver–child pairs from paediatric wards in Harare, Zimbabwe, once children who had been hospitalised with SAM were ready for discharge. Children were median 17.8 months old, and 28.6% had human immunodeficiency virus. Trained intervention facilitators (IFs)—lay workers whose own children had previously had SAM—delivered the intervention over 12 weeks with nurse supervision. Qualitative interviews with caregivers and IFs showed that the intervention was feasible and acceptable. Participants reported benefiting from the psychosocial support and counselling, and several started income‐generating projects. Caregivers appreciated the concept of play and caregiver–child interaction, and all reported practising what they had learned. By Week 12, caregiver mental health and caregiver–child interaction improved significantly. Overall, the intervention was feasible, acceptable and showed promise in modifying caregiver knowledge, attitudes and practice. An efficacy trial is now needed to evaluate whether the intervention can improve child convalescence following complicated SAM. We codesigned an intervention package for children recovering from complicated severe acute malnutrition (SAM) in Zimbabwe, providing child stimulation through play, and strengthening caregiver capabilities through problem‐solving skills, peer support and income‐generating activities. The package was delivered by trained lay workers and was feasible and acceptable to caregivers, providing a potential new strategy to holistically enhance the home psychosocial environment during SAM convalescence. Key messages A psychosocial intervention which enhances child play and promotes caregiver support may improve convalescence following severe acute malnutrition. We co‐designed a complex intervention, designed to provide child stimulation through play, and to strengthen caregiver and household capabilities through problem‐solving skills, peer support and income‐generating activities. The 12‐week intervention, delivered by trained lay workers whose own children had previously had SAM, was feasible and acceptable, and caregivers showed improvements in mental health and caregiver‐child interaction. This psychosocial support package should now be tested in a randomised trial to evaluate its efficacy in promoting convalescence.
Journal Article
Recovery of children following hospitalisation for complicated severe acute malnutrition
by
Ngosa, Deophine
,
Nathoo, Kusum J.
,
Sturgeon, Jonathan P.
in
Caregivers
,
Cerebral palsy
,
Cerebral Palsy - therapy
2022
Nutritional recovery and hospital readmission following inpatient management of complicated severe acute malnutrition (SAM) are poorly characterised. We aimed to ascertain patterns and factors associated with hospital readmission, nutritional recovery and morbidity, in children discharged from hospital following management of complicated SAM in Zambia and Zimbabwe over 52‐weeks posthospitalization. Multivariable Fine‐Gray subdistribution hazard models, with death and loss to follow‐up as competing risks, were used to identify factors associated with hospital readmission; negative binomial regression to assess time to hospitalisation and ordinal logistic regression to model factors associated with nutritional recovery. A total of 649 children (53% male, median age 18.2 months) were discharged to continue community nutritional rehabilitation. All‐cause hospital readmission was 15.4% (95% CI 12.7, 18.6) over 52 weeks. Independent risk factors for time to readmission were cerebral palsy (adjusted subhazard ratio (aSHR): 2.96, 95% CI 1.56, 5.61) and nonoedematous SAM (aSHR: 1.64, 95%CI 1.03, 2.64). Unit increases in height‐for‐age Z‐score (HAZ) (aSHR: 0.82, 95% CI 0.71, 0.95) and enrolment in Zambia (aSHR: 0.52, 95% CI 0.28, 0.97) were associated with reduced subhazard of time to readmission. Young age, SAM at discharge, nonoedematous SAM and cerebral palsy were associated with poor nutritional recovery throughout follow‐up. Collectively, nonoedematous SAM, ongoing SAM at discharge, cerebral palsy and low HAZ are independent risk factors for readmission and poor nutritional recovery following complicated SAM. Children with these high‐risk features should be prioritised for additional convalescent care to improve long‐term outcomes. Nutritional recovery and hospital readmission following inpatient management of complicated severe acute malnutrition (SAM) are poorly characterised. We aimed to ascertain patterns and factors associated with hospital readmission, nutritional recovery and morbidity, in children discharged from hospital following management of complicated SAM in Zambia and Zimbabwe over 52‐weeks posthospitalization. Nonoedematous SAM, ongoing SAM at discharge, cerebral palsy and low height‐for‐age Z‐score were found to be independent risk factors for readmission and poor recovery following complicated SAM. Key messages One‐in‐six children managed for SAM were readmitted into hospital over the first year after discharge and one‐in‐eight remained undernourished by 52 weeks of follow‐up. Nonoedematous SAM, ongoing SAM at the time of discharge and underlying cerebral palsy were independent risk factors for hospital readmission and poor nutritional recovery. Low HAZ was a risk factor for hospital readmission and poor nutritional recovery. Postdischarge care should focus on children with disability, nonoedematous SAM at initial hospitalisation and have ongoing SAM at the time of discharge. Stunting should be considered in the management of children with SAM.
Journal Article