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ABSTRACT: BACKGROUND: The World Health Organization (WHO) classifies Guinea-Bissau as having severe vitamin A deficiency (VAD). To date, no national survey has been conducted. We assessed vitamin A status among children in rural Guinea-Bissau to assess status and identify risk factors for VAD. METHODS: In a vitamin A supplementation trial in rural Guinea-Bissau, children aged 6 months to 2 years who were missing one or more vaccines were enrolled, vaccinated and randomized to vitamin A or placebo. Provided consent, a dried blood spot (DBS) sample was obtained from a subgroup of participants prior to supplementation. Vitamin A status and current infection was assessed by an ELISA measuring retinol-binding protein (RBP) and C-reactive protein (CRP). VAD was defined as RBP concentrations equivalent to plasma retinol <0.7 mumol/L; infection was defined as CRP >5 ml/L. In Poisson regression models providing prevalence ratios (PR), we investigated putative risk factors for VAD including sex, age, child factors, maternal factors, season (rainy: June-November; dry: December-May), geography, and use of health services. RESULTS: Based on DBS from 1102 children, the VAD prevalence was 65.7% (95% confidence interval 62.9-68.5), 11% higher than the WHO estimate of 54.7% (9.9-93.0). If children with infection were excluded, the prevalence was 60.2% (56.7-63.7). In the age group 9--11 months, there was no difference in prevalence of VAD among children who had received previous vaccines in a timely fashion and those who had not. Controlled for infection and other determinants of VAD, the prevalence of VAD was 1.64 (1.49-1.81) times higher in the rainy season compared to the dry, and varied up to 2-fold between ethnic groups and regions. Compared with having an inactivated vaccine as the most recent vaccine, having a live vaccine as the most recent vaccination was associated with lower prevalence of VAD (PR=0.84 (0.74-0.96)). CONCLUSIONS: The prevalence of VAD was high in rural Guinea-Bissau. VAD varied significantly with season, ethnicity, region, and vaccination status.Trial registration: Clinicaltrials.gov NCT00514891.
BMC Public Health 02/2013; 13(1):172. · 2.00 Impact Factor
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ABSTRACT: Twins traditionally retain a special status in many African societies. In Guinea-Bissau, twins are often well regarded yet still suffer from a very high mortality, especially in the perinatal and infant period. At the Bandim Health Project, a health and demographic surveillance site, we have recently established one of the first twin registries in Sub-Saharan Africa. Our short-term aim is to describe twin mortality and morbidity in order to design appropriate health interventions. Our long-term goal is a large-scale database to explore the pathogenesis of prevalent diseases; for example, diabetes mellitus, metabolic syndrome, and infectious diseases such as HIV, tuberculosis, and malaria. A major focus area is also the etiology of low birth weight and how epigenetic processes might modulate the consequences of low birth weight in Sub-Saharan Africa. For this, monozygotic twin studies represent a powerful tool. Though twin studies have been carried out by the Bandim Health Project for more than 30 years, the renewed registry described here was officially established in 2009 and includes both a cohort of newborn twins and a cohort of young and adult twins. Currently more than 1,500 twins are being followed in the two cohorts combined. We believe that the registry holds exciting possibilities and will encourage the establishment of further twin registries across the region.
Twin Research and Human Genetics 10/2012; · 1.70 Impact Factor
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Peter Aaby,
Henrik Ravn,
Adam Roth, Amabelia Rodrigues,
Ida Maria Lisse,
Birgitte Rode Diness,
Karen Rokkedal Lausch,
Najaaraq Lund,
Julie Rasmussen,
Sofie Biering-Sørensen,
Hilton Whittle,
Christine Stabell Benn
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ABSTRACT: Studies from low-income countries have suggested that diphtheria-tetanus-pertussis (DTP) vaccine provided after Bacille Calmette-Guerin (BCG) vaccination may have a negative effect on female survival. The authors examined the effect of DTP in a cohort of low birthweight (LBW) infants.
2320 LBW newborns were visited at 2, 6 and 12 months of age to assess nutritional and vaccination status. The authors examined survival until the 6-month visit for children who were DTP vaccinated and DTP unvaccinated at the 2-month visit.
Two-thirds of the children had received DTP at 2 months and 50 deaths occurred between the 2-month and 6-month visits. DTP vaccinated children had a better anthropometric status for all indices than DTP unvaccinated children. Small mid-upper arm circumference (MUAC) was the strongest predictor of mortality. The death rate ratio (DRR) for DTP vaccinated versus DTP unvaccinated children differed significantly for girls (DRR 2.45; 95% CI 0.93 to 6.45) and boys (DRR 0.53; 95% CI 0.23 to 1.20) (p=0.018, homogeneity test). Adjusting for MUAC, the overall effect for DTP vaccinated children was 2.62 (95% CI 1.34 to 5.09); DRR was 5.68 (95% CI 1.83 to 17.7) for girls and 1.29 (95% CI 0.56 to 2.97) for boys (p=0.023, homogeneity test). While anthropometric indices were a strong predictor of mortality among boys, there was little or no association for girls.
Surprisingly, even though the children with the best nutritional status were vaccinated early, early DTP vaccination was associated with increased mortality for girls.
Archives of Disease in Childhood 02/2012; 97(8):685-91. · 2.88 Impact Factor
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ABSTRACT: The WHO aims for 90% coverage of the Expanded Program on Immunization (EPI), which in Guinea-Bissau included BCG vaccine at birth, three doses of diphtheria-tetanus-pertussis vaccine (DTP) and oral polio vaccine (OPV) at 6, 10 and 14 weeks and measles vaccine (MV) at 9 months when this study was conducted. The WHO assesses coverage by 12 months of age. The sequence of vaccines may have an effect on child mortality, but is not considered in official statistics or assessments of programme performance. We assessed vaccination coverage and frequency of out-of-sequence vaccinations by 12 and 24 months of age.
Observational cohort study.
The Bandim Health Project's (BHP) rural Health and Demographic Surveillance site covers 258 randomly selected villages in all regions of Guinea-Bissau. Villages are visited biannually and vaccination cards inspected to ascertain vaccination status. Between 2003 and 2009 vaccination status by 12 months of age was assessed for 5806 children aged 12-23 months; vaccination status by 24 months of age was assessed for 3792 children aged 24-35 months.
Coverage of EPI vaccinations and frequency of out-of-sequence vaccinations.
Half of 12-month-old children and 65% of 24-month-old children had completed all EPI vaccinations. Many children received vaccines out of sequence: by 12 months of age 54% of BCG-vaccinated children had received DTP with or before BCG and 28% of measles-vaccinated children had received DTP with or after MV. By 24 months of age the proportion of out-of-sequence vaccinations was 58% and 35%, respectively, for BCG and MV.
In rural Guinea-Bissau vaccination coverage by 12 months of age was low, but continued to increase beyond 12 months of age. More than half of all children received vaccinations out of sequence. This highlights the need to improve vaccination services.
BMJ open. 01/2012; 2(6).
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ABSTRACT: Little is known about how health research systems (HRS) in low-income countries emerge and evolve over time, and how this process relates to their performance. Understanding how HRSs emerge is important for the development of well functioning National Health Research Systems (NHRS). The aim of this study was to assess how the HRS in Guinea Bissau has emerged and evolved over time and how the present system functions.
We used a qualitative case-study methodology to explore the emergence and current performance of the HRS, using the NHRS framework. We reviewed documents and carried out 39 in-depth interviews, ranging from health research to policy and practice stakeholders. Using an iterative approach, we undertook a thematic analysis of the data.
The research practices in Guinea Bissau led to the emergence of a HRS with both local and international links and strong dependencies on international partners and donors. The post-colonial, volatile and resource-dependent context, changes in donor policies, training of local researchers and nature of the research findings influenced how the HRS evolved. Research priorities have mostly been set by 'expatriate' researchers and focused on understanding and reducing child mortality. Research funding is almost exclusively provided by foreign donors and international agencies. The training of Guinean researchers started in the mid-nineties and has since reinforced the links with the health system, broadened the research agenda and enhanced local use of research. While some studies have made an important contribution to global health, the use of research within Guinea Bissau has been constrained by the weak and donor dependent health system, volatile government, top-down policies of international agencies, and the controversial nature of some of the research findings.
In Guinea Bissau a de facto 'system' of research has emerged through research practices and co-evolving national and international research and development dynamics. If the aim of research is to contribute to local decision making, it is essential to modulate the emerged system by setting national research priorities, aligning funding, building national research capacity and linking research to decision making processes. Donors and international agencies can contribute to this process by coordinating their efforts and aligning to national priorities.
Health Research Policy and Systems 01/2012; 10:5. · 1.38 Impact Factor
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ABSTRACT: Measles vaccines (MV) have sex-differential effects on mortality not explained by protection against measles infection.
The authors examined whether whole-cell diphtheria-tetanus-pertussis (DTP) vaccine has sex-differential and non-specific effects. DATA SOURCES AND ELIGIBILITY: Following previous reviews and a new search, the effect of DTP on mortality up to the next vaccination was assessed in all studies where DTP was given after BCG or DTP was given after MV and there was prospective follow-up after ascertainment of vaccination status.
High-mortality countries in Africa and Asia.
The initial observation of negative effect of DTP generated six hypotheses, which were examined in all available studies and two randomised trials reducing the time of exposure to DTP.
Consistency between studies.
In the first study, DTP had negative effects on survival in contrast to the beneficial effects of BCG and MV. This pattern was repeated in the six other studies available. Second, the two 'natural experiments' found significantly higher mortality for DTP-vaccinated compared with DTP-unvaccinated children. Third, the female-male mortality ratio was increased after DTP in all nine studies; in contrast, the ratio was decreased after BCG and MV in all studies. Fourth, the increased female mortality associated with high-titre measles vaccine was found only among children who had received DTP after high-titre measles vaccine. Fifth, in six randomised trials of early MV, female but not male mortality was increased if DTP was likely to be given after MV. Sixth, the mortality rate declined markedly for girls but not for boys when DTP-vaccinated children received MV. The authors reduced exposure to DTP as most recent vaccination by administering a live vaccine (MV and BCG) shortly after DTP. Both trials reduced child mortality.
These observations are incompatible with DTP merely protecting against the targeted diseases. With herd immunity to whooping cough, DTP is associated with higher mortality for girls. Randomised studies of DTP are warranted to measure the true impact on survival.
BMJ open. 01/2012; 2(3).
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ABSTRACT: The current policy of measles vaccination at 9 months of age was decided in the mid-1970s. The policy was not tested for impact on child survival but was based on studies of seroconversion after measles vaccination at different ages. The authors examined the empirical evidence for the six underlying assumptions.
Secondary analysis.
These assumptions have not been research issues. Hence, the authors examined case reports to assess the empirical evidence for the original assumptions. The authors used existing reviews, and in December 2011, the authors made a PubMed search for relevant papers. The title and abstract of papers in English, French, Portuguese, Spanish, German and Scandinavian languages were assessed to ascertain whether the paper was potentially relevant. Based on cumulative measles incidence figures, the authors calculated how many measles cases had been prevented assuming everybody was vaccinated at a specific age, how many 'vaccine failures' would occur after the age of vaccination and how many cases would occur before the specific age of vaccination. In the combined analyses of several studies, the authors used the Mantel-Haenszel weighted RR stratifying for study or age groups to estimate common trends.
African community studies of measles infection. PRIMARY AND SECONDARY OUTCOMES: Consistency between assumptions and empirical evidence and the predicted effect on mortality.
In retrospect, the major assumptions were based on false premises. First, in the single study examining this point, seronegative vaccinated children had considerable protection against measles infection. Second, in 18 community studies, vaccinated measles cases ('vaccine failures') had threefold lower case death than unvaccinated cases. Third, in 24 community studies, infants had twofold higher case death than older measles cases. Fourth, the only study examining the assumption that 'vaccine failures' lead to lack of confidence found the opposite because vaccinated children had milder measles infection. Fifth, a one-dose policy was recommended. However, the two randomised trials of early two-dose measles vaccination compared with one-dose vaccination found significantly reduced mortality until 3 years of age. Thus, current evidence suggests that the optimal age for a single dose of measles vaccine should have been 6 or 7 months resulting in fewer severe unvaccinated cases among infants but more mild 'vaccine failures' among older children. Furthermore, the two-dose trials indicate that measles vaccine reduces mortality from other causes than measles infection.
Many lives may have been lost by not determining the optimal age of measles vaccination. Since seroconversion continues to be the basis for policy, the current recommendation is to increase the age of measles vaccination to 12 months in countries with limited measles transmission. This policy may lead to an increase in child mortality.
BMJ open. 01/2012; 2(4).
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ABSTRACT: A total of 105 low-birth-weight children presenting for first vaccination were randomized to receive bacillus Calmette-Guérin (BCG) immediately or later (current practice). The mortality rate ratio for BCG was 0.17 (95% CI = 0.02-1.35) within 3 days of enrollment, 0.28 (0.06-1.37) in the first month, and 0.27 (0.07-0.98) after 2 months of age. The mortality rate ratio was 0.41 (0.14-1.18) (P = 0.098) in infancy. Administration of BCG vaccine at first contact may contribute to lower mortality.
The Pediatric Infectious Disease Journal 12/2011; 31(3):306-8. · 3.58 Impact Factor
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The Journal of Infectious Diseases 12/2011; 205(3):515-7. · 6.41 Impact Factor
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ABSTRACT: Vitamin A supplementation (VAS) given to children between 6 months and 5 years of age is known to reduce mortality in low-income countries. We have previously observed that girls benefit more from a lower dose of VAS than the one recommended by WHO, the effect being strongest if diphtheria-tetanus-pertussis vaccine (DTP) was the most recent vaccination. We aimed to test these observations.
During national immunisations days in Guinea-Bissau, West Africa, combining oral polio vaccination and VAS, we randomised 8626 children between 6 months and 5 years of age to receive the dose of VAS recommended by WHO or half this dose. Mortality rate ratios (MRRs) were assessed after 6 and 12 month.
The overall mortality rate among participants was lower than expected. There was no significant difference in mortality at 6 months and 12 months of follow up between the low dose VAS group and the recommended dose VAS group. The MRRs were 1.23 (0.60-2.54) after 6 months and 1.17 (0.73-1.87) after 12 months. This tendency was similar in boys and girls. The low dose was not associated with lower mortality in girls if the most recent vaccine was DTP (MRR = 0.60 (0.14-2.50) after 6 months).
Our sample size does not permit firm conclusions since mortality was lower than expected. We could not confirm a beneficial effect of a lower dose of VAS on mortality in girls.
The study was registered under clinicaltrials.gov, number NCT00168636.
BMC Pediatrics 09/2011; 11:77. · 1.88 Impact Factor
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Peter Aaby,
Adam Roth,
Henrik Ravn,
Bitiguida Mutna Napirna, Amabelia Rodrigues,
Ida Maria Lisse,
Lone Stensballe,
Birgitte Rode Diness,
Karen Rokkedal Lausch,
Najaaraq Lund,
Sofie Biering-Sørensen,
Hilton Whittle,
Christine Stabell Benn
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ABSTRACT: Observational studies have suggested that BCG may have nonspecific beneficial effects on survival. Low-birth-weight (LBW) children are not given BCG at birth in Guinea-Bissau; we conducted a randomized trial of BCG at birth (early BCG) vs delayed BCG.
In the period 2004-2008 we recruited 2320 LBW children in Bissau. The children were visited at home at 2, 6, and 12 months of age. With a pretrial infant mortality of 250 per 1000, we hypothesized a 25% reduction in infant mortality for LBW children.
Infant mortality was only 101 per 1000 during the trial. In the primary analysis, infant mortality was reduced insignificantly by 17% (mortality rate ratio [MRR] = .83 [.63-1.08]). In secondary analyses, early BCG vaccine was safe with an MRR of .49 (.21-1.15) after 3 days and .55 (.34-.89) after 4 weeks. The reduction in neonatal mortality was mainly due to fewer cases of neonatal sepsis, respiratory infection, and fever. The impact of early BCG on infant mortality was marked for children weighing <1.5 kg (MRR = .43 [.21-.85]) who had lower coverage for diphtheria-tetanus-pertussis vaccinations.
Though early BCG did not reduce infant mortality significantly, it may have a beneficial effect in the neonatal period. This could be important for public health because BCG is often delayed in low-income countries.
The Journal of Infectious Diseases 07/2011; 204(2):245-52. · 6.41 Impact Factor
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ABSTRACT: Most developing countries are implementing the WHO immunisation programme. Although vaccines reach most children, many modifications of the recommended schedule are observed in practice. We investigated the association between vaccination status and risk of hospitalisation in Guinea-Bissau.
From May 2003 to May 2004, all consultations of children less than five years of age at the outpatient clinic of the paediatric ward at the national hospital in Bissau were registered. For each consultation, information was collected about the child's name, sex, age and socio-cultural conditions, as well as diagnosis and whether the child was hospitalised. Information about vaccinations was also registered from the child's vaccination card. We analysed the association between vaccination status and risk of hospitalisation in age intervals according to the pre-dominant vaccines. We particularly emphasised the comparison of those who had received the recommended vaccination for the age groups and those who were delayed and only had the previous vaccinations. We also examined those who had received the vaccines out of sequence.
Information about vaccinations was available for 11,949 outpatient children of whom 2219 (19%) were hospitalised. Among children less than 3 months of age, unvaccinated children compared to BCG children had as expected a higher risk of hospitalisation; controlled for important determinants of hospitalisation, the hospitalisation risk ratio (HRR) was 1.99 (95% CI 1.37-2.89). In contrast, there was no difference in the HRR for children aged 1½-8 months who were delayed and had only received BCG compared to those who as recommended had received diphtheria-tetanus-pertussis (DTP) vaccine after BCG (HRR=1.10 (0.77-1.59)). In the age interval 9-17 months of age, children who were delayed and had only received DTP had significantly higher risk of hospitalisation compared with children who as recommended had measles vaccine (MV) as the most recent vaccination (HRR=1.39 (1.16-1.66)). Having received DTP after MV (HRR=1.60 (1.15-2.24)) or MV and DTP simultaneously (HRR=1.51 (1.16-1.97)) was also associated with higher risk than MV only as most recent vaccination. In contrast, the children aged 18-59 months who as recommended had received a DTP booster after MV did not have lower risk of hospitalisations compared with children who were delayed and had received only MV (RR=0.90 (0.75-1.07)). After 9 months of age, there was a significant difference in the female-male HRR for children who had MV (HRR=0.85 (0.72-1.00)) or DTP (HRR=1.08 (0.96-1.22)) as most recent vaccination (p=0.02, test of interaction).
Following the recommended vaccination schedule for BCG and MV is associated with a reduced risk of hospitalisation but this is not the case for DTP and booster DTP. Receiving DTP simultaneously with MV or after MV is associated with increased risk of hospitalisation. Vaccines have sex-differential effects on the risk of hospitalisation.
Vaccine 03/2011; 29(20):3662-9. · 3.77 Impact Factor
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ABSTRACT: Vitamin A treatment reduces mortality during acute measles infection, and vitamin A supplementation (VAS) to children above 6 months of age may reduce the incidence of measles infection. The effect of VAS at birth on measles incidence is unknown. In a randomised placebo-controlled trial in Guinea-Bissau, normal-birth-weight newborns were randomised to 50 000 IU (15 mg) VAS or placebo. During the trial, a measles epidemic occurred. We linked data from the trial with data from the measles infection surveillance and studied the effect of VAS on the measles incidence before 12 months of age in both sexes. A total of 165 measles cases were identified among the 4183 children followed from 28 d of age. Up to 6 months of age, the incidence rate ratio of measles for VAS compared with placebo was 0·54 (95 % CI 0·25, 1·15) among boys and 1·57 (95 % CI 0·80, 3·08) among girls (test of interaction, P = 0·04). The corresponding figures at 12 months were 0·67 (95 % CI 0·43, 1·05) and 1·17 (95 % CI 0·76, 1·79) (test of interaction, P = 0·08). VAS compared with placebo tended to be associated with less measles hospitalisation or death during the first 6 months of life in boys (P = 0·06), but not in girls. VAS at birth may affect the susceptibility to measles infection during the first 6 months of life in a sex-differential manner.
The British journal of nutrition 02/2011; · 3.45 Impact Factor
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ABSTRACT: In 2008, Guinea-Bissau introduced artemether-lumefantrine for treatment of uncomplicated malaria. Previously, 3 times the standard dose of chloroquine, that was probably efficacious against Plasmodium falciparum with the resistance-associated chloroquine-resistance transporter (pfcrt) 76T allele, was routinely used. The present study compared the efficacy and tolerability of a double standard dose of chloroquine with the efficacy and tolerability of artemether-lumefantrine.
In a randomized open-label clinical trial, artemether-lumefantrine or chloroquine (50 mg/kg) were given as 6 divided doses over 3 days to children aged 6 months--15 years who had uncomplicated P. falciparum monoinfection. Drug concentrations were measured on day 7. P. falciparum multidrug resistance gene N86Y and pfcrt K76T alleles were identified.
The polymerase chain reaction-adjusted day 28 and 42 treatment efficacies were 162 (97%) of 168 and 155 (97%) of 161, respectively, for artemether-lumefantrine and 150 (95%) of 158 and 138 (94%) of 148, respectively, for chloroquine. When parasites with resistance-associated pfcrt 76T were treated, the day 28 efficacy of chloroquine was 87%. No severe drug-related adverse events were detected. Symptom resolution was similar with both treatments.
Both treatments achieved the World Health Organization-recommended efficacy for antimalarials that will be adopted as policy. High-dose chloroquine treatment regimes should be further evaluated with the aim of assessing chloroquine as a potential partner drug to artemisinin derivatives. Clinical trials registration. NCT00426439.
The Journal of Infectious Diseases 01/2011; 203(1):109-16. · 6.41 Impact Factor
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ABSTRACT: The current guidelines for treatment of malaria include paracetamol to children with fever. No convincing evidence for the beneficial effects of this practice exists. Studies show that time to parasite clearance is significantly longer in children treated with paracetamol, which questions the policy. Whether this is of clinical importance has not been investigated.
Children with Plasmodium falciparum monoinfection and ≥20 parasites per 200 leucocytes at the Bandim Health Centre, Guinea-Bissau were randomized to receive paracetamol or placebo together with chloroquine for three days in a double blind randomized study. Temperature and symptoms were recorded twice daily during treatment and on day 3. The participants were interviewed and a malaria film taken once weekly until day 35. The data is in the form of grouped failure-times, the outcome of interest being time until parasitaemia during follow-up. Mantel-Haenszel weighted odds ratios are given. Other differences between and within the two groups have been tested using the Chi-square test and Mann-Whitney U test.
In the evening of the day of inclusion, the temperature was slightly, but statistically insignificant, higher in the placebo group and significantly more children complained of headache. At no other time was a significant difference in temperature or symptoms detected. However, 6 children from the placebo-group as compared to two children from the paracetamol-group were admitted to hospital with high fever and convulsions by day 3. No differences in the cumulative percentages of children with adequate clinical and parasitological response were found in the intention-to-treat analysis or in the per-protocol analysis.
Fewer children had early treatment failure and the mean temperature was slightly lower in the afternoon on day 0 in the paracetamol group. However, the cumulative adequate clinical and parasitological cure rates were not significantly different during the period of study. It is doubtful whether adding paracetamol to the treatment of uncomplicated malaria in children is beneficial.
NCT00137566.
Malaria Journal 01/2011; 10:148. · 3.19 Impact Factor
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ABSTRACT: Within a randomised trial of neonatal vitamin A supplementation (VAS) in Guinea-Bissau, neonatal VAS did not affect overall infant mortality. We conducted a post-hoc analysis to test the hypothesis that neonatal VAS primes the response to subsequent vitamin A.
All trial children were offered VAS after follow-up ended at 1 year of age (FU-VAS). We compared mortality between 1 and 3 years of age according to initial randomization to neonatal VAS or placebo in Cox-regression models; we expected that children randomized to neonatal VAS compared with those randomized to placebo would have lower mortality after reception of FU-VAS.
Of 4345 infants enrolled in the original trial, 3646 lived in the study area at 1 year of age and 2958 received FU-VAS. Between 1 and 3 years of age, 112 children died. After FU-VAS, neonatal VAS was associated with lower mortality than placebo: Mortality Rate Ratio (MRR) = 0.54 (95%CI: 0.31-0.94). The effect was more pronounced in girls (MRR = 0.37 (0.16-0.89)) than boys (MRR = 0.73 (0.35-1.51)). The beneficial effect of neonatal VAS may have been particularly strong for girls who received both VAS in a campaign and FU-VAS (MRR = 0.15 (0.03-0.67)). Among children who had not received FU-VAS, mortality in the second and third year of life did not differ according to reception of neonatal VAS or placebo. Hence, in the second and third year of life the effect of neonatal VAS versus placebo was different in girls who had or had not received FU-VAS (p for homogeneity = 0.01).
The present results suggest that neonatal VAS primes the response in girls such that they get a beneficial effect after a subsequent dose of VAS.
Clinicaltrials.gov NCT00168597.
PLoS ONE 01/2011; 6(8):e23265. · 4.09 Impact Factor
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ABSTRACT: Vitamin A supplements may interact with diphtheria-tetanus-pertussis (DTP) vaccine causing increased female mortality. In a randomised trial of neonatal vitamin A supplementation (VAS), we examined growth during the first year of life in 808 children, pursuing the hypothesis that a negative interaction between VAS and DTP in girls would be reflected in growth. Length and weight were measured at 6 weekly visits and WHO-growth-reference z-scores derived. Neonatal VAS had no effect on anthropometric measures at 12 months, but may interact sex differentially with routine vaccines. While BCG was the most recent vaccine, neonatal VAS benefitted growth (difference in weight-for-length z-score (dWFL: 0.31(95% CI: 0.03-0.59)). While DTP was the most recent vaccine, VAS tended to affect growth adversely in girls (dWFL = -0.21 (-0.48-0.06)). After measles vaccine (MV) there was no overall effect of neonatal VAS. The VAS effect differed significantly between the BCG and DTP windows (P = 0.03), and the difference was borderline significant between the DTP and MV windows for girls (P = 0.09).
Journal of Tropical Medicine 01/2011; 2011:570170.
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ABSTRACT: Prophylactic vitamin A supplementation (VAS) reduces mortality and may reduce morbidity associated with diarrhea in children >6 months of age. Rotavirus is the most common cause of acute dehydrating diarrhea among children worldwide.
In a randomized placebo-controlled study of 50,000 IU of vitamin A versus placebo given with bacille Calmette-Guérin vaccine at birth, 287 infants were followed up with weekly interviews and stool sample obtainment to test the hypothesis that VAS reduced the risk of rotavirus infection.
VAS was associated with increased risk of rotavirus infection and diarrhea (incidence rate ratio [IRR] of infection, 1.72 [95% confidence interval (CI), 1.04-2.85]; IRR of diarrhea, 3.74 [95% CI, 1.40-9.98]) among children <6 months of age. There was no effect in older children. VAS had a beneficial effect on nonrotavirus diarrhea in boys <6 months of age (IRR, 0.51; 95% CI, 0.27-0.95) and a detrimental effect in girls >6 months of age (IRR, 1.84; 95% CI, 0.96-3.55).
VAS at birth did not reduce rotavirus morbidity. The effect of VAS on nonrotavirus diarrhea may differ by sex, being more beneficial in boys. Clinical trials registration. NCT00168597 .
The Journal of Infectious Diseases 09/2010; 202 Suppl:S243-51. · 6.41 Impact Factor
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ABSTRACT: A number of trials on maternal multi-micronutrient supplementation (MMS) have found a benefical effect on birth weight, but few have demonstrated a beneficial effect on infant survival. We examined the effect of two different preparations of antenatal MMS on fetal loss and under-2-years child mortality, as compared with iron-folic acid supplementation among 2,100 pregnant women in Guinea-Bissau. Women receiving a 1xRDA MMS preparation (consisting of 14 vitamins and minerals) had a marginally reduced risk of fetal loss (Relative risk (RR) 0.65, 95% CI 0.40; 1.05), and women receiving a 2xRDA MMS preparation had a similar effect (RR 0.67, 95% CI 0.42; 1.08), the pooled effect being 0.66 (95% CI 0.44; 0.99). None of the supplements reduced under-2-years mortality or the combination of fetal loss and under-2-years mortality. There was a marginally negative effect of both the 1xRDA (RR 2.10, 95% CI 0.99; 4.46) and the 2xRDA (RR 2.02, 95% CI 0.95; 4.32) MMS preparation on mortality specifically between 92-365 days of age.
African Journal of Reproductive Health 06/2010; 14(2):17-26.
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Christine Stabell Benn,
Ane Baerent Fisker,
Bitiguida Mutna Napirna,
Adam Roth,
Birgitte Rode Diness,
Karen Rokkedal Lausch,
Henrik Ravn,
Maria Yazdanbakhsh, Amabelia Rodrigues,
Hilton Whittle,
Peter Aaby
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ABSTRACT: To investigate the effect of vitamin A supplementation and BCG vaccination at birth in low birthweight neonates.
Randomised, placebo controlled, two by two factorial trial.
Bissau, Guinea-Bissau.
1717 low birthweight neonates born at the national hospital.
Neonates who weighed less than 2.5 kg were randomly assigned to 25 000 IU vitamin A or placebo, as well as to early BCG vaccine or the usual late BCG vaccine, and were followed until age 12 months.
Mortality, calculated as mortality rate ratios (MRRs), after follow-up to 12 months of age for infants who received vitamin A supplementation compared with those who received placebo.
No interaction was observed between vitamin A supplementation and BCG vaccine allocation (P=0.73). Vitamin A supplementation at birth was not significantly associated with mortality: the MRR of vitamin A supplementation compared with placebo, controlled for randomisation to "early BCG" versus "no early BCG" was 1.08 (95% CI 0.79 to 1.47). Stratification by sex revealed a significant interaction between vitamin A supplementation and sex (P=0.046), the MRR of vitamin A supplementation being 0.74 (95% CI 0.45 to 1.22) in boys and 1.42 (95% CI 0.94 to 2.15) in girls. When these data were combined with data from a complementary trial among normal birthweight neonates in Guinea-Bissau, the combined estimate of the effect of neonatal vitamin A supplementation on mortality was 1.08 (95% CI 0.87 to 1.33); 0.80 (95% CI 0.58 to 1.10) in boys and 1.41 (95% CI 1.04 to 1.90) in girls (P=0.01 for interaction between neonatal vitamin A and sex).
The combined results of this trial and the complementary trial among normal birthweight neonates have now shown that, overall, it would not be beneficial to implement a neonatal vitamin A supplementation policy in Guinea-Bissau. Worryingly, the trials show that vitamin A supplementation at birth can be harmful in girls. Previous studies and future trials should investigate the possibility that vitamin A supplementation has sex differential effects. Trial registration ClinicalTrials.gov NCT00168610.
BMJ (Clinical research ed.). 01/2010; 340:c1101.
