Infectious Diseases - Research Publications

Permanent URI for this collection

Search Results

Now showing 1 - 4 of 4
  • Item
    Thumbnail Image
    The role of fingernail selenium in the association between arsenic, lead and mercury and child development in rural Vietnam: a cross-sectional analysis
    Egwunye, J ; Cardoso, BR ; Braat, S ; Tran, H ; Hanieh, S ; Hare, D ; Duan, AX ; Doronila, A ; Thach, T ; Tran, T ; Fisher, J ; Biggs, B-A (CAMBRIDGE UNIV PRESS, 2023-05-14)
    As, Pb and Hg are common environmental contaminants in low- and middle-income countries. We investigated the association between child toxicant exposure and growth and development and determined if this association was mitigated by Se concentration. Toxicant concentrations in fingernail samples, anthropometry and Bayley's Scales of Infant Development, 3rd edition domains were assessed in 36-month-old children whose mothers had been part of a randomised controlled trial in rural Vietnam. Multivariable regression analyses were performed to estimate the effect of toxicant exposure on clinical outcomes with adjustments for potential confounders and interaction with fingernail Se concentration. We analysed 658 children who had data for at least one physical or developmental outcome, and at least one toxicant measurement, and each of the covariates. Fingernail As concentration was negatively associated with language (estimate per 10 % increase in As: -0·19, 95 % CI: (-0·32, -0·05)). Pb was negatively associated with cognition (estimate per 10 % increase in Pb: -0·08 (-0·15, -0·02)), language (estimate per 10 % increase in Pb: -0·18 (-0·28, -0·10)) and motor skills (estimate per 10 % increase in Pb: -0·12 (-0·24, 0·00)). Hg was negatively associated with cognition (estimate per 10 % increase in Hg: -0·48, (-0·72, -0·23)) and language (estimate per 10 % increase in Hg -0·51, (-0·88, -0·13)) when Se concentration was set at zero in the model. As Se concentration increased, the negative associations between Hg and both cognition and language scores were attenuated. There was no association between toxicant concentration and growth. As, Pb and Hg concentrations in fingernails of 3-year-old children were associated with lower child development scores. The negative association between Hg and neurological development was reduced in magnitude with increasing Se concentration. Se status should be considered when assessing heavy metal toxicants in children and their impact on neurodevelopmental outcomes.
  • Item
    Thumbnail Image
    Child linear growth trajectories during the first three years of life in relation to infant iron status: a prospective cohort study in rural Vietnam
    Hanieh, S ; Braat, S ; Tran, TD ; Ha, TT ; Simpson, JA ; Tuan, T ; Fisher, J ; Biggs, B-A (BMC, 2022-02-15)
    BACKGROUND: Early childhood growth patterns have long-term consequences for health and disease. Little is known about the interplay between growth and iron status during childhood. We explored the interplay between linear growth and iron status during early childhood, by assessing child growth trajectories between 6 and 36 months (m) of age in relation to infant iron status at 6 months of age. METHODS: A cohort study of infants born to women who had previously participated in a cluster randomized controlled trial of antenatal micronutrient supplementation, conducted in rural Vietnam. The relationship between child linear growth trajectories and infant iron status (ferritin concentration) was examined using latent growth curve modeling. Primary outcomes were height for age z scores (HAZ) and growth trajectory between 6 and 36 m of age. RESULTS: A total of 1112 infants were included in the study. Mean [SD] HAZ scores decreased over time from -0·58 [0·94] at 6 m, to -0·97 [0·99] at 18 m, to -1·14 [0·89] at 36 m of age. There was a steep linear decline in the HAZ scores between 6 and 18 m of age, followed by a slower linear decline from 18 to 36 m of age. Ferritin concentration at 6 m of age was inversely associated with HAZ score at 6 m of age (-0·145, 95% CI [-0.189, -0.101]). There was no association between infant ferritin at 6 m of age and child growth trajectory between 6 and 36 m of age. CONCLUSIONS: Iron status at six months of age did not influence a child's later linear growth trajectory in this cohort of rural Vietnamese children. Longitudinal studies with repeated ferritin and height measurements are required to better delineate this relationship and inform public health interventions.
  • Item
    Thumbnail Image
    Continuing breastfeeding for at least two years after birth in rural Vietnam: prevalence and psychosocial characteristics
    Doma, H ; Tran, TD ; Tran, T ; Hanieh, S ; Tran, H ; Nguyen, T ; Biggs, B-A ; Fisher, J (BMC, 2021-10-12)
    BACKGROUND: The World Health Organization recommends breastfeeding for at least two years (24 months or more) after birth. In Vietnam, 22% of women continue breastfeeding for at least two years. The aim of this study was to determine the sociodemographic and psychosocial characteristics of mother-baby dyads associated with breastfeeding for 24 months or more in a rural setting in Vietnam. METHODS: A secondary analysis was conducted on existing data obtained from a prospective study in Ha Nam, Vietnam. Women were recruited when they were pregnant and were followed up until 36 months after giving birth. The data were collected between 2009 and 2011. The associations between sociodemographic and psychosocial characteristics and continued breastfeeding for 24 months or more were examined using a multivariable logistic regression model. RESULTS: Overall, 363 women provided complete data which were included in the analyses. Among those, 20.9% breastfed for 24 months or more. Women who were 31 years old or older were more likely to breastfeed for 24 months or more than women who were 20 years old or younger (adjusted odds ratio, AOR, 9.54 [95% CI 2.25, 40.47]). Women who gave birth to girls were less likely to breastfeed for 24 or more months than women who had boys (AOR 0.44; 95% CI 0.25, 0.80). CONCLUSIONS: This study provides evidence that may be useful for policy-makers to help improve breastfeeding practices for all children in Vietnam by targeting policy towards younger women and women with girls to promote continued breastfeeding for at least 24 months.
  • Item
    Thumbnail Image
    Social and economic development and pregnancy mental health: secondary analyses of data from rural Vietnam
    Stocker, R ; Nguyen, T ; Tran, T ; Tran, H ; Tran, T ; Hanieh, S ; Biggs, B-A ; Fisher, J (BMC, 2020-06-26)
    BACKGROUND: This study aimed to establish whether changes in the socioeconomic context were associated with changes in population-level antenatal mental health indicators in Vietnam. METHODS: Social, economic and public policies introduced in Vietnam (1986-2010) were mapped. Secondary analyses of data from two cross-sectional community-based studies conducted in 2006 (n = 134) and 2010 (n = 419), involving women who were ≥ 28 weeks pregnant were completed. Data for these two studies had been collected in structured individual face-to-face interviews, and included indicators of antenatal mental health (mean Edinburgh Postnatal Depression Scale Vietnam-validation (EPDS-V) score), intimate partner relationships (Intimate Bonds Measure Vietnam-validation) and sociodemographic characteristics. Socioeconomic characteristics and mean EPDS-V scores in the two study years were compared and mediation analyses were used to establish whether indicators of social and economic development mediated differences in EPDS-V scores. RESULTS: Major policy initiatives for poverty reduction, hunger eradication and making domestic violence a crime were implemented between 2006 and 2010. Characteristics and circumstances of pregnant women in Ha Nam improved significantly. Mean EPDS-V score was lower in 2010, indicating better population-level antenatal mental health. Household wealth and intimate partner controlling behaviours mediated the difference in EPDS-V scores between 2006 and 2010. CONCLUSIONS: Changes in the socioeconomic and political context, particularly through policies to improve household wealth and reduce domestic violence, appear to influence women's lives and population-level antenatal mental health. Cross-sectoral policies that reduce social risk factors may be a powerful mechanism to improve antenatal mental health at a population level.