Inflammation, cytomegalovirus and the growth hormone axis in HIV-exposed uninfected Zimbabwean infants.

OBJECTIVES: Despite avoiding HIV infection, HIV-exposed uninfected (HEU) infants have poorer clinical outcomes than HIV-unexposed infants, including impaired growth. The growth hormone (GH) axis is an important regulator of infant growth through hepatic synthesis of insulin-like growth-factor-1 (IGF-1), and may be disrupted by chronic inflammation and acute infections, including cytomegalovirus (CMV). We tested the hypothesis that these factors lead to disruption of the GH axis in HEU infants, which might contribute to their impaired growth. DESIGN: Substudy of 343 infants from the ZVITAMBO trial in Harare, Zimbabwe. METHODS: IGF-1, growth parameters, C-reactive protein (CRP) and CMV viraemia were evaluated in 243 HEU infants and 100 HIV-unexposed infants. Univariable linear and logistic regression models were used to determine associations between IGF-1 and growth parameters, CRP and CMV. RESULTS: Mean 6-week IGF-1 was significantly lower in HEU compared with HIV-unexposed infants (29.6 vs. 32.6 ng/ml; P = 0.014), and associated with subsequent linear and ponderal growth through 6 months of age. CRP was inversely correlated with IGF-1 in all infants regardless of HIV exposure status (β = -0.84; P = 0.03). CMV viral loads were inversely correlated with IGF-1 in HEU (β = -1.16; P = 0.008) but not HIV-unexposed (β = 0.21; P = 0.83) infants. CONCLUSION: Overall, we found evidence for greater disruption of the GH axis in HEU compared with HIV-unexposed infants as early as 6 weeks of age, suggesting a role for reduced IGF-1 in mediating growth impairment in HEU infants. Inflammation and coinfections may be drivers of growth impairment in HEU infants by disrupting the GH axis

Independent and combined effects of improved water, sanitation, and hygiene, and improved complementary feeding, on child stunting and anaemia in rural Zimbabwe: a cluster-randomised trial.

BACKGROUND: Child stunting reduces survival and impairs neurodevelopment. We tested the independent and combined effects of improved water, sanitation, and hygiene (WASH), and improved infant and young child feeding (IYCF) on stunting and anaemia in in Zimbabwe. METHODS: We did a cluster-randomised, community-based, 2 × 2 factorial trial in two rural districts in Zimbabwe. Clusters were defined as the catchment area of between one and four village health workers employed by the Zimbabwe Ministry of Health and Child Care. Women were eligible for inclusion if they permanently lived in clusters and were confirmed pregnant. Clusters were randomly assigned (1:1:1:1) to standard of care (52 clusters), IYCF (20 g of a small-quantity lipid-based nutrient supplement per day from age 6 to 18 months plus complementary feeding counselling; 53 clusters), WASH (construction of a ventilated improved pit latrine, provision of two handwashing stations, liquid soap, chlorine, and play space plus hygiene counselling; 53 clusters), or IYCF plus WASH (53 clusters). A constrained randomisation technique was used to achieve balance across the groups for 14 variables related to geography, demography, water access, and community-level sanitation coverage. Masking of participants and fieldworkers was not possible. The primary outcomes were infant length-for-age Z score and haemoglobin concentrations at 18 months of age among children born to mothers who were HIV negative during pregnancy. These outcomes were analysed in the intention-to-treat population. We estimated the effects of the interventions by comparing the two IYCF groups with the two non-IYCF groups and the two WASH groups with the two non-WASH groups, except for outcomes that had an important statistical interaction between the interventions. This trial is registered with ClinicalTrials.gov, number NCT01824940. FINDINGS: Between Nov 22, 2012, and March 27, 2015, 5280 pregnant women were enrolled from 211 clusters. 3686 children born to HIV-negative mothers were assessed at age 18 months (884 in the standard of care group from 52 clusters, 893 in the IYCF group from 53 clusters, 918 in the WASH group from 53 clusters, and 991 in the IYCF plus WASH group from 51 clusters). In the IYCF intervention groups, the mean length-for-age Z score was 0·16 (95% CI 0·08-0·23) higher and the mean haemoglobin concentration was 2·03 g/L (1·28-2·79) higher than those in the non-IYCF intervention groups. The IYCF intervention reduced the number of stunted children from 620 (35%) of 1792 to 514 (27%) of 1879, and the number of children with anaemia from 245 (13·9%) of 1759 to 193 (10·5%) of 1845. The WASH intervention had no effect on either primary outcome. Neither intervention reduced the prevalence of diarrhoea at 12 or 18 months. No trial-related serious adverse events, and only three trial-related adverse events, were reported. INTERPRETATION: Household-level elementary WASH interventions implemented in rural areas in low-income countries are unlikely to reduce stunting or anaemia and might not reduce diarrhoea. Implementation of these WASH interventions in combination with IYCF interventions is unlikely to reduce stunting or anaemia more than implementation of IYCF alone. FUNDING: Bill & Melinda Gates Foundation, UK Department for International Development, Wellcome Trust, Swiss Development Cooperation, UNICEF, and US National Institutes of Health.The SHINE trial is funded by the Bill & Melinda Gates Foundation (OPP1021542 and OPP113707); UK Department for International Development; Wellcome Trust, UK (093768/Z/10/Z, 108065/Z/15/Z and 203905/Z/16/Z); Swiss Agency for Development and Cooperation; US National Institutes of Health (2R01HD060338-06); and UNICEF (PCA-2017-0002)

Intestinal Damage and Inflammatory Biomarkers in Human Immunodeficiency Virus (HIV)-Exposed and HIV-Infected Zimbabwean Infants

Andrew J Prendergast, Bernard Chasekwa, Sandra Rukobo, Margaret Govha, Kuda Mutasa, Robert Ntozini, Jean H Humphrey; Intestinal Damage and Inflammatory Biomarkers in Human Immunodeficiency Virus (HIV)–Exposed and HIV-Infected Zimbabwean Infants, The Journal of Infectious Diseases, Volume 216, Issue 6, 15 September 2017, Pages 651–661, https://doi.org/10.1093/infdis/jix36

Cytomegalovirus Acquisition and Inflammation in Human Immunodeficiency Virus-Exposed Uninfected Zimbabwean Infants

Barts Charity (grant no. MGU0300 to C. E.). C. E. is funded by the National Institute for Health Research. A.  J. P.  is funded by the Wellcome Trust (grant no. 108065/Z/15/Z). The ZVITAMBO trial was supported by the Canadian International Development Agency (CIDA) (R/C Project 690/ M3688), United States Agency for International Development (USAID) (cooperative agreement number HRN-A-00-97-00015-00 between Johns Hopkins University and the Office of Health and Nutrition–USAID), and a grant from the Bill and Melinda Gates Foundation, Seattle, Washington. Additional funding was received from the SARA Project, which is operated by the Academy for Educational Development, Washington DC, and is funded by USAID’s Bureau for Africa, Office of Sustainable Development under the terms of contract AOT-C-00-99-00237-00, the Rockefeller Foundation (New York, NY) and BASF (Ludwigshafen, Germany)

Neonatal vitamin A supplementation and immune responses to oral polio vaccine in Zimbabwean infants.

Background: Micronutrient deficiencies may contribute to reduced oral vaccine immunogenicity in developing countries. We hypothesised that neonatal vitamin A supplementation (NVAS) would improve oral vaccine responses. Methods: We performed a cross-sectional study of infants recruited at birth to the Zimbabwe Vitamin A for Mothers and Babies (ZVITAMBO) trial, a randomised controlled trial of single, high-dose NVAS vs placebo conducted in Zimbabwe between 1997-2001. We measured poliovirus-specific IgA to type 1-3 polio strains by semiquantitative capture ELISA in cryopreserved plasma samples collected at 6 months of age. Results: A total of 181 infants fulfilled inclusion criteria, of whom 80 were randomised to NVAS and 101 to placebo. There were no significant differences in baseline characteristics between groups. At 6 months of age, median (IQR) vaccine titres for infants randomised to NVAS vs placebo were 932 (421-3001) vs 1774 (711-5431) for Sabin-1 (p=0.04); 1361 (705-3402) vs 2309 (1081-4283) for Sabin-2 (p=0.15); and 1584 (796-4216) vs 2260 (996-5723) for Sabin-3 (p=0.14), respectively. After adjusting for breast feeding status, birth weight, season and infant sex in a linear regression model, there was only weak evidence of difference in log mean titres between vitamin A and placebo groups for Sabin-1 (p=0.08) and no evidence of difference in log mean titres for Sabin-2 and Sabin-3. Conclusions: NVAS did not augment oral polio vaccine responses in Zimbabwean infants. Further research is required to understand the impact of NVAS on responses to other oral vaccines. The trial is registered with clinicaltrials.gov identifier: NCT00198718.The ZVITAMBO trial was supported by the Canadian International Development Agency (CIDA) (R/C Project 690/M3688), United States Agency for International Development (USAID) (cooperative agreement number HRN-A-00-97-00015-00 between Johns Hopkins University and the Office of Health and Nutrition – USAID) and a grant from the Bill and Melinda Gates Foundation, Seattle WA. Additional funding was received from the SARA Project, which is operated by the Academy for Educational Development, Washington DC and is funded by USAID’s Bureau for Africa, Office of Sustainable Development under the terms of Contract AOT-C-00-99-00237-00, the Rockefeller Foundation (NY, NY) and BASF (Ludwigshafen, Germany). This current study was supported by the Sanitation & Hygiene Applied Research for Equity (SHARE) Consortium and Barts Charity (grant number 212563 to JAC). JAC (Grant 201293/Z/16/Z) and AJP (Grant 108065/Z/15/Z) are supported by the Wellcome Trust

Immune responses to oral poliovirus vaccine in HIV-exposed uninfected Zimbabwean infants.

It remains uncertain whether HIV-exposed uninfected (HEU) infants have impaired responses to oral vaccines. We performed a cross-sectional study of 6-month-old infants recruited at birth to the ZVITAMBO trial in Zimbabwe between 1997-2001, before introduction of prevention of mother-to-child transmission interventions. We measured poliovirus-specific IgA to type 1-3 polio strains by semi-quantitative capture ELISA in cryopreserved serum samples collected from 85 HEU and 101 HIV-unexposed infants at 6 months of age, one month after their last immunisation with trivalent OPV. Almost all infants were breastfed, with the majority in both groups mixed breastfed (70.6% HEU versus 71.3% HIV-unexposed). Median (IQR) vaccine titers for HEU and HIV-unexposed infants were 1592 (618-4896) vs. 1774 (711-5431) for Sabin 1 (P = 0.46); 1895 (810-4398) vs. 2308 (1081-4283) for Sabin 2 (P = 0.52); and 1798 (774-4192) vs. 2260 (996-5723) for Sabin 3 (P = 0.18). There were no significant differences in vaccine titers between HEU and HIV-unexposed infants, suggesting that vertical HIV exposure does not impact oral poliovirus vaccine immunogenicity.ZVITAMBO trial was supported by the Canadian International Development Agency (CIDA) (R/C Project 690/M3688), United States Agency for International Development (USAID) (cooperative agreement number HRN-A-00-97-00015-00 between Johns Hopkins University and the Office of Health and Nutrition – USAID) and a grant from the Bill and Melinda Gates Foundation, Seattle WA. Additional funding was received from the SARA Project, which is operated by the Academy for Educational Development, Washington DC and is funded by USAID’s Bureau for Africa, Office of Sustainable Development under the terms of Contract AOT-C-00-99-00237-00, the Rockefeller Foundation (NY, NY) and BASF (Ludwigshafen, Germany). This current study was supported by the Sanitation & Hygiene Applied Research for Equity (SHARE) Consortium and Barts Charity (grant number 212563 to JAC). JAC (Grant 201293/Z/16/Z) and AJP (Grant 108065/Z/15/Z) are supported by the Wellcome Trust

Predictors of oral rotavirus vaccine immunogenicity in rural Zimbabwean infants.

BACKGROUND: Oral rotavirus vaccines (RVV) have poor immunogenicity in low-income countries, for reasons that remain unclear. This study identified the determinants of RVV immunogenicity among infants in rural Zimbabwe. METHODS: Anti-rotavirus IgA titres were measured among a sub-group of infants enrolled in the Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial (NCT01824940). SHINE was a cluster-randomized trial of improved infant and young child feeding, and improved water, sanitation and hygiene (WASH) in two rural Zimbabwean districts. Infants received RVV as part of the national immunisation programme. Among HIV-unexposed infants in the non-WASH trial arms, we evaluated associations between potential risk factors (vaccine schedule and dose, maternal and infant nutritional status, infant diarrhoea, and household environment) and RVV immunogenicity (seroconversion, seropositivity and geometric mean titres) using multivariable regression. RESULTS: Among 219 infants with seroconversion data, 43 (20%) successfully seroconverted and 176 (80%) failed to seroconvert to RVV. Seroconversion was positively associated with a higher length-for-age Z-score (LAZ) around the time of vaccination (adjusted RR 1.27 (95% CI 1.04, 1.55), P = 0.021), and negatively associated with concurrent OPV and RVV administration (adjusted RR 0.36 (0.19, 0.71), P = 0.003). Among 472 infants with post-vaccination titres, a higher LAZ score was associated with increased seropositivity (aRR 1.21 (95% CI 1.06, 1.38), P = 0.004), and higher birthweight was associated with increased IgA titres (0.45 (95%CI 0.18, 1.09) U/mL greater per 100 g gain in birthweight; P = 0.001). CONCLUSIONS: Infant ponderal and linear growth were positively associated with RVV immunogenicity, while concurrent administration of OPV was negatively associated with RVV immunogenicity. Together, these findings suggest that improving foetal growth and separating RVV and OPV administration are plausible approaches to increasing RVV immunogenicity

Biomarkers of environmental enteric dysfunction are not consistently associated with linear growth velocity in rural Zimbabwean infants.

BACKGROUND: Child stunting remains a poorly understood, prevalent public health problem. Environmental enteric dysfunction (EED) is hypothesized to be an important underlying cause. OBJECTIVES: Within a subgroup of 1169 children enrolled in the SHINE (Sanitation Hygiene Infant Nutrition Efficacy) trial in rural Zimbabwe, followed longitudinally from birth to 18 mo of age, we evaluated associations between the concentration of 11 EED biomarkers and linear growth velocity. METHODS: At infant ages 1, 3, 6, 12, and 18 mo, nurses measured child length and collected stool and blood; the lactulose-mannitol urine test was also conducted at all visits except at 1 mo. Stool neopterin, α-1 antitrypsin, myeloperoxidase, and regenerating gene 1β protein; urinary lactulose and mannitol; and plasma kynurenine, tryptophan, C-reactive protein, insulin-like growth factor-1 (IGF-1), soluble CD14, intestinal fatty acid binding protein, and citrulline were measured. We analyzed the change in relative [∆ length-for-age z score (LAZ)/mo] and absolute (∆ length/mo) growth velocity during 4 age intervals (1-3 mo; 3-6 mo; 6-12 mo; and 12-18 mo) per SD increase in biomarker concentration at the start of each age interval. RESULTS: In fully adjusted models, we observed only 3 small, statistically significant associations: kynurenine:tryptophan ratio at 12 mo was associated with decreased mean LAZ velocity during the 12-18 mo interval (-0.015 LAZ/mo; 95% CI: -0.029, -0.001 LAZ/mo); mannitol excretion at 6 mo was associated with increased LAZ velocity during the 6-12 mo interval (0.013 LAZ/mo; 95% CI: 0.001, 0.025 LAZ/mo), and plasma IGF-1 at 1 mo was associated with increased LAZ velocity during the 1-3 mo interval (0.118 LAZ/mo; 95% CI: 0.024, 0.211 LAZ/mo). Results for absolute growth velocity were similar, except IGF-1 was also associated with growth during the 12-18 mo interval. We found no other associations between any EED biomarker and linear growth velocity. CONCLUSIONS: None of 11 biomarkers of EED were consistently associated with linear growth among Zimbabwean children.This trial was registered at clinicaltrials.gov as NCT01824940

Stunting status and exposure to infection and inflammation in early life shape anti-bacterial immune cell function among Zimbabwean children

Background: Children 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 anti-bacterial immune function would differ between stunted and non-stunted children and relate to their health and environment during early life. Methods: We 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 24h 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. Results: Children 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): 3.46pg/mL (1.09, 10.80), p=0.035) and IL-8 (3.52pg/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): 10.48pg/mL (1.84, 60.31), p=0.008) and HKST-specific MPO (5.10pg/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). Conclusions: Anti-bacterial 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

Associations between biomarkers of environmental enteric dysfunction and oral rotavirus vaccine immunogenicity in rural Zimbabwean infants

Background: Oral rotavirus vaccines (RVV) are poorly immunogenic in low-income countries. Environmental enteric dysfunction (EED) resulting from poor water, sanitation and hygiene (WASH) may contribute. We therefore tested associations between EED and RVV immunogenicity, and evaluated the effect of improved WASH on EED. Methods: We measured nine biomarkers of EED among Zimbabwean infants born to mothers enrolled in a cluster-randomised 2 × 2 factorial trial of improved WASH and improved feeding between November 2012 and March 2015 (NCT01824940). We used multivariable regression to determine associations between EED biomarkers and RVV seroconversion, seropositivity and geometric mean titer. Log-binomial regression was used to evaluate the effect of improved WASH on EED. Findings: Among 303 infants with EED biomarkers and immunogenicity data, plasma intestinal fatty-acid binding protein and stool myeloperoxidase were positively associated with RVV seroconversion; adjusted RR 1.63 (95%CI 1.04, 2.57) and 1.29 (95%CI 1.01, 1.65), respectively. There were no other associations between RVV immunogenicity and either individual biomarkers or EED domains (intestinal permeability, intestinal damage, intestinal inflammation and microbial translocation). EED biomarkers did not differ between randomised WASH and non-WASH groups. Interpretation: We found no evidence that EED was associated with poor RVV immunogenicity. Contrary to our hypothesis, there was weak evidence that EED was associated with increased seroconversion. EED biomarkers were not affected by a package of household-level WASH interventions