Infectious Diseases - Research Publications
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ItemNo Preview AvailableCorrection: Does Malaria Affect Placental Development? Evidence from In Vitro Models(Public Library of Science (PLoS), 2013)
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ItemNo Preview AvailableEvaluation of Haemophilus influenzae Type b Vaccine for Routine Immunization in Nepali Infants(Wolters Kluwer Health, 2012-04)BACKGROUND: Haemophilus influenzae type b (Hib) carriage and disease studies in Nepali children suggest a significant burden of infection. Hib conjugate vaccines (HibCV) do not have uniform immunogenicity between populations. We determined the immunogenicity of HibCV in Nepali infants, before its introduction into the routine immunization schedule. METHODS: Ninety infants recruited at Patan Hospital, Kathmandu, received 3 doses of the HibCV with routine immunizations (diphtheria, tetanus, whole cell pertussis-hepatitis B vaccine + oral polio vaccine) at 6, 10 and 14 weeks of age, and a HibCV booster at 52 weeks. Anti-polyribosylribitol phosphate (PRP) concentrations were measured at 18, 52 and 56 weeks, and the antibody persistence at 52 weeks was compared with antibody values in unimmunized controls (n = 30). RESULTS: After 3 doses of primary immunizations, at 18 weeks of age (n = 74), all infants had anti-PRP concentrations above the accepted thresholds for short- and long-term protection (0.15 and 1.0 µg/mL, respectively). At 1 year of age, before administration of the booster of HibCV, the anti-PRP geometric mean antibody concentration was 2.76 µg/mL (confidence interval: 1.88-4.07) in sera from the immunized children compared with 0.11 µg/mL (95% confidence interval: 0.08-0.17) in the nonimmunized control group (n = 30). Twenty-seven percent (20/74) of participants, however, had anti-PRP concentrations <1.0 µg/mL. Four weeks after the booster dose of HibCV, 98.5% of infants had anti-PRP concentrations above 1.0 µg/mL. CONCLUSION: Immunization with HibCV given as part of the Expanded Program on Immunization schedule in Nepal elicits robust antibody responses. Though the antibody wanes during the first year of life, most 1-year-old infants remain protected and respond robustly to a booster dose of the vaccine.
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ItemNo Preview AvailableCerebral phaeohyphomycosis caused by Cladophialophora bantiana in a patient with chronic lymphocytic leukemia(Elsevier, 2006-07-15)The phaeohyphomycoses are infections caused by dematiaceous fungi. The dark pigmentation results from the melanin in their cell walls, which may be one of the factors responsible for the virulence and pathogenic potential of these fungi (1). Cladophialophora bantiana is highly neurotropic and accounts for the majority of cases of cerebral phaeohyphomycosis. Unlike many of the opportunistic fungi, most reported cases of cerebral phaeohyphomycosis caused by C. bantiana have occurred in immunocompetent patients. C. bantiana infection is often reported as being resistant to conventional medical therapy and as having an overall poor prognosis, regardless of immune status. Medical therapy is not standardized, and clinical experience with the newer azoles, such as voriconazole, has been limited.
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ItemConsidering equity and cost-effectiveness in assessing a parenting intervention to promote early childhood development in rural Vietnam(OXFORD UNIV PRESS, 2023-09-18)Considering equity in early childhood development (ECD) is important to ensure healthy development for every child. Equity-informative cost-effectiveness analysis can further guide decision makers to maximize outcomes with limited resources while promoting equity. This cost-effectiveness study aimed to examine the equity impacts of a multicomponent ECD intervention in rural Vietnam. We estimated the cost-effectiveness of the intervention with a 30-month time horizon from the service provider and household perspectives with equity considerations. Data were from a cluster-randomized controlled trial comparing the intervention with the local standard of care. The incremental cost-effectiveness ratios (ICERs) per child cognitive development score gained were estimated by household wealth quintile and maternal education level, adjusted for cluster effects and baseline characteristics such as maternal parity and age. A 3% discount rate was applied to costs, and non-parametric cluster bootstrapping was used to examine uncertainty around ICERs. Children in the intervention had higher cognitive development scores than those in the control arm across all subgroups. Based on intervention recurrent cost, the ICER per cognitive development score gained was lower in children from the poorest quintile (-US$6) compared to those from the richest quintile (US$16). Similarly, the ICER per cognitive development score gained was lower in children whose mothers had the lowest education level (-US$0.02) than those with mothers who had the highest education level (US$7). Even though our findings should be interpreted with caution due to the insufficient study power, the findings suggest that the intervention could promote equity while improving child cognitive development with greater cost-effectiveness in disadvantaged groups.
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ItemPromoting early childhood development in Viet Nam: cost-effectiveness analysis alongside a cluster-randomised trial.(Elsevier BV, 2023-08)BACKGROUND: Economic evaluations are critical to ensure effective resource use to implement and scale up child development interventions. This study aimed to estimate the cost-effectiveness of a multicomponent early childhood development intervention in rural Viet Nam. METHODS: We did a cost-effectiveness study alongside a cluster-randomised trial with a 30-month time horizon. The study included 669 mothers from 42 communes in the intervention group, and 576 mothers from 42 communes in the control group. Mothers in the intervention group attended Learning Clubs sessions from mid-pregnancy to 12 months after delivery. The primary outcomes were child cognitive, language, motor, and social-emotional development at age 2 years. In this analysis, we estimated the incremental cost-effectiveness ratios (ICERs) of the intervention compared with the usual standard of care from the service provider and household perspectives. We used non-parametric bootstrapping to examine uncertainty, and applied a 3% discount rate. FINDINGS: The total intervention cost was US$169 898 (start-up cost $133 692 and recurrent cost $36 206). The recurrent cost per child was $58 (1 341 741 Vietnamese dong). Considering the recurrent cost alone, the base-case ICER was $14 and mean ICER of 1000 bootstrap samples was $14 (95% CI -0·48 to 30) per cognitive development score gained with a 3% discount rate to costs. The ICER per language and motor development score gained was $22 and $20, respectively, with a 3% discount rate to costs. INTERPRETATION: The intervention was cost-effective: the ICER per child cognitive development score gained was 0·5% of Viet Nam's gross domestic product per capita, alongside other benefits in language and motor development. This finding supports the scaling up of this intervention in similar socioeconomic settings. FUNDING: Australian National Health and Medical Research Council and Grand Challenges Canada. TRANSLATION: For the Vietnamese translation of the abstract see Supplementary Materials section.
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ItemNo Preview AvailablePrevalence and risk factors for symptoms of common mental disorders in early and late pregnancy in Vietnamese women: A prospective population-based study(Elsevier, 2013-04-05)BACKGROUND: Little is known about the prevalence of and risk factors for common mental disorders (CMD) in pregnant women in low-income countries. The aim of this study was to establish the prevalence of and psychosocial risk factors for clinically significant symptoms of CMD in early and late pregnancy in women in rural Viet Nam. METHODS: A population-based sample of women was surveyed in early and late pregnancy. CMD were assessed by the Edinburgh Postnatal Depression Scale-Viet Nam Validation and psychosocial risks by study-specific structured interviews. RESULTS: In total 497/523 (97%) eligible women were recruited and 419 (84%) provided complete data. Prevalence of CMD only in early pregnancy was 22.4% (95% CI 18.4-26.4); only in late pregnancy was 10.7% (95% CI 7.8-13.7) and at both assessment waves was 17.4% (95% CI 13.8-21.1). Non-economic and economic coincidental life adversity, intimate partner violence, past pregnancy loss, and childhood abuse were positively associated with persistent antenatal CMD. Older age, having a preference for the baby's sex, and nulli- or primiparity were risk factors for CMD in early pregnancy. CONCLUSIONS: Persistent antenatal CMD are prevalent in rural areas of Viet Nam. Psychosocial risk factors play a major role in this significant public health problem.
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ItemThe Effect of Intermittent Antenatal Iron Supplementation on Infant Outcomes in Rural Vietnam: A Cluster Randomized Trial(SCIENCEDOMAIN International, 2015)Objectives: Intermittent antenatal iron supplementation is an attractive alternative to daily dosing during pregnancy, however the impact of this strategy on infant outcomes remains unclear. We compared the effect of intermittent antenatal iron supplementation with daily iron supplementation on maternal and infant outcomes in rural Vietnam. Methods: This cluster randomised trial was conducted in Ha Nam province, Vietnam. 1,258 pregnant women in 104 communes were assigned to daily iron-folic acid (IFA), twice weekly IFA, or twice weekly multiple micronutrient (MMN) supplementation. Primary outcome was birth weight. Results: There was no difference in birth weights of infants of women receiving twice weekly IFA compared to daily IFA (mean difference [MD] 28 g; 95% CI -22 to 78), or twice weekly MMN compared to daily IFA (MD -36.8 g; 95% CI -82 to 8.2). At 32 wk gestation, maternal ferritin was lower in women receiving twice weekly compared to daily IFA (geometric mean ratio (GMR) 0.73; 95% CI 0.67 to 0.80), and in women receiving twice weekly MMN compared to daily IFA (GMR 0.62; 95% CI 0.57 to 0.68), with no difference in hemoglobin levels. Infants of mothers who received twice weekly IFA had higher cognitive scores at 6 mo of age compared to those who received daily IFA (MD 1.89; 95% CI 0.23 to 3.56). Conclusions: Twice-weekly antenatal IFA supplementation achieved similar mean birthweight, and improved cognitive scores in infants at 6 months of age, compared to daily IFA supplementation, and should be considered for use in settings with low anemia prevalence.
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ItemNo Preview AvailableStructured, multicomponent, community-based programme for women?s health and infant health and development in rural Vietnam: a parallel-group cluster randomised controlled trial(ELSEVIER SCI LTD, 2023-05)BACKGROUND: Interventions to improve early childhood development have previously addressed only one or a few risk factors. Learning Clubs is a structured, facilitated, multicomponent programme designed to address eight potentially modifiable risk factors, and offered from mid-pregnancy to 12 months post partum; we aimed to establish whether this programme could improve the cognitive development of children at 2 years of age. METHODS: For this parallel-group cluster-randomised controlled trial, 84 of 116 communes (the clustering unit) in HaNam Province in rural Vietnam were randomly selected and randomly assigned to receive the Learning Clubs intervention (n=42) or usual care (n=42). Women aged at least 18 years who were pregnant (gestational age <20 weeks) were eligible for inclusion. Data sources were standardised, and study-specific questionnaires assessing risks and outcomes were completed in interviews in mid-pregnancy (baseline), late pregnancy (after 32 weeks of gestation), at 6-12 months post partum, and at the end of the study period when children were 2 years of age. Mixed-effects models were used to estimate trial effects, adjusting for clustering. The primary outcome was the cognitive development of children at 2 years of age, assessed by the Bayley Scales of Infant and Toddler Development Third Edition (Bayley-III) cognitive score. This trial is registered with the Australian New Zealand Clinical Trials Registry (ACTRN12617000442303). FINDINGS: Between April 28, 2018, and May 30, 2018, 1380 women were screened and 1245 were randomly assigned (669 to the intervention group and 576 to the control group). Data collection was completed on Jan 17, 2021. Data at the end of the study period were contributed by 616 (92%) of 669 women and their children in the intervention group, and by 544 (94%) of 576 women and their children in the control group. Children aged 2 years in the intervention group had significantly higher mean Bayley-III cognitive scores than those in the control group (99·6 [SD 9·7] vs 95·6 [9·4]; mean difference 4·00 [95% CI 2·56-5·43]; p<0·0001). At 2 years of age, 19 (3%) children in the intervention group had Bayley-III scores less than 1 SD, compared with 32 (6%) children in the control group, but this difference was not significant (odds ratio 0·55 [95% CI 0·26-1·17]; p=0·12). There were no significant differences between groups in maternal, fetal, newborn, or child deaths. INTERPRETATION: A facilitated, structured, community-based, multicomponent group programme improved early childhood development to the standardised mean in rural Vietnam and could be implemented in other similarly resource-constrained settings. FUNDING: Australian National Health and Medical Research Council and Grand Challenges Canada Saving Brains Initiative. TRANSLATION: For the Vietnamese translation of the abstract see Supplementary Materials section.
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ItemThe role of fingernail selenium in the association between arsenic, lead and mercury and child development in rural Vietnam: a cross-sectional analysis(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.
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ItemChild linear growth trajectories during the first three years of life in relation to infant iron status: a prospective cohort study in rural Vietnam(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.