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1.
Bull World Health Organ ; 102(3): 176-186, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38420570

RESUMO

Objective: To investigate the effect of daily iron supplementation for 14 weeks on the serum iron concentration and other markers of iron status in exclusively breastfed infants in Gambia. Methods: A placebo-controlled, randomized, double-blind trial was performed in rural Gambia between 3 August 2021 and 9 March 2022. Overall, 101 healthy, exclusively breastfed infants aged 6 to 10 weeks were recruited at vaccination clinics and through community health workers. Infants were randomized to receive iron supplementation (7.5 mg/day as ferrous sulfate in sorbitol solution) or placebo for 98 days. Venous blood samples were collected at baseline and on day 99 to assess the serum iron concentration and other markers of iron and haematological status. Findings: At day 99, the serum iron concentration was significantly higher in the iron supplementation group than the placebo group (crude difference in means: 2.5 µmol/L; 95% confidence interval: 0.6 to 4.3) and there were significant improvements in other iron and haematological markers. There were 10 serious adverse events (five in each group), 106 non-serious adverse events (54 with iron supplementation; 52 with placebo) and no deaths. There was no marked difference between the groups in maternally reported episodes of diarrhoea, fever, cough, skin infection, eye infection or nasal discharge. Conclusion: In exclusively breastfed Gambian infants, iron supplementation from 6 weeks of age was associated with a significant improvement in markers of iron status at around 6 months of age. There was no indication of adverse effects on growth or infections.


Assuntos
Aleitamento Materno , Ferro , Lactente , Feminino , Humanos , Ferro/efeitos adversos , Gâmbia , Suplementos Nutricionais/efeitos adversos
2.
Br J Nutr ; 131(4): 707-719, 2024 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-37795629

RESUMO

Adolescent girls are an important target group for micronutrient interventions particularly in Sub-Saharan Africa where adolescent pregnancy and micronutrient deficiencies are common. When consumed in sufficient amounts and at levels appropriate for the population, fortified foods may be a useful strategy for this group, but little is known about their effectiveness and timing (regarding menarche), particularly in resource-poor environments. We evaluated the effect of consuming multiple micronutrient-fortified biscuits (MMB), sold in the Ghanaian market, 5 d/week for 26 weeks compared with unfortified biscuits (UB) on the micronutrient status of female adolescents. We also explored to what extent the intervention effect varied before or after menarche. Ten2Twenty-Ghana was a 26-week double-blind, randomised controlled trial among adolescent girls aged 10-17 years (n 621) in the Mion District, Ghana. Biomarkers of micronutrient status included concentrations of Hb, plasma ferritin (PF), soluble transferrin receptor (TfR) and retinol-binding protein (RBP), including body-iron stores. Intention-to-treat analysis was supplemented by protocol-specific analysis. We found no effect of the intervention on PF, TfR and RBP. MMB consumption did not affect anaemia and micronutrient deficiencies at the population level. MMB consumption increased the prevalence of vitamin A deficiency by 6·2 % (95 % CI (0·7, 11·6)) among pre-menarche girls when adjusted for baseline micronutrient status, age and height-for-age Z-score, but it decreased the prevalence of deficient/low vitamin A status by -9·6 % (95 % CI (-18·9, -0·3)) among post-menarche girls. Consuming MMB available in the market did not increase iron status in our study, but reduced the prevalence of deficient/low vitamin A status in post-menarcheal girls.


Assuntos
Anemia Ferropriva , Desnutrição , Oligoelementos , Adolescente , Feminino , Humanos , Gravidez , Anemia Ferropriva/epidemiologia , Anemia Ferropriva/prevenção & controle , Ferritinas , Alimentos Fortificados/análise , Gana/epidemiologia , Ferro , Micronutrientes , Estado Nutricional , Vitamina A , Criança
3.
Br J Nutr ; 131(2): 248-255, 2024 01 28.
Artigo em Inglês | MEDLINE | ID: mdl-37560803

RESUMO

The combined sandwich-ELISA (s-ELISA; VitMin Lab, Germany) and the Quansys Q-Plex™ Human Micronutrient Array (7-Plex) are multiplex serum assays that are used to assess population micronutrient status in low-income countries. We aimed to compare the agreement of five analytes, α-1-acid glycoprotein (AGP), C-reactive protein (CRP), ferritin, retinol-binding protein 4 (RBP4) and soluble transferrin receptor (sTfR) as measured by the 7-Plex and the s-ELISA. Serum samples were collected between March 2016 and December 2017. Pregnant women (n 249) were recruited at primary healthcare clinics in Johannesburg, and serum samples were collected between March 2016 and December 2017. Agreement between continuous measurements was assessed by Bland-Altman plots and concordance measures. Agreement in classifications of deficiency or inflammation was assessed by Cohen's kappa. Strong correlations (r > 0·80) were observed between the 7-Plex and s-ELISA for CRP and ferritin. Except for CRP, the 7-Plex assay gave consistently higher measurements than the s-ELISA. With the exception of CRP (Lin's ρ = 0·92), there was poor agreement between the two assays, with Lin's ρ < 0·90. Discrepancies of test results difference between methods increased as the serum concentrations rose. Cohen's kappa for all the five analytes was < 0·81 and ranged from slight agreement (vitamin A deficiency) to substantial (inflammation and Fe deficiency) agreement. The 7-Plex 1.0 is a research and or surveillance tool with potential for use in low-resource laboratories but cannot be used interchangeably with the s-ELISA. Further optimising and validation is required to establish its interchangeability with other validated methods.


Assuntos
Anemia Ferropriva , Oligoelementos , Humanos , Feminino , Gravidez , Gestantes , Micronutrientes , África do Sul , Ferritinas , Proteína C-Reativa/metabolismo , Inflamação , Oligoelementos/metabolismo , Biomarcadores , Anemia Ferropriva/epidemiologia , Proteínas Plasmáticas de Ligação ao Retinol
4.
Matern Child Nutr ; 19(4): e13528, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37244872

RESUMO

Nutrition-sensitive agriculture programmes have the potential to improve child nutrition outcomes, but livestock intensification may pose risks related to water, sanitation and hygiene (WASH) conditions. We assessed the impact of SELEVER, a nutrition- and gender-sensitive poultry intervention, with and without added WASH focus, on hygiene practices, morbidity and anthropometric indices of nutrition in children aged 2-4 years in Burkina Faso. A 3-year cluster randomised controlled trial was implemented in 120 villages in 60 communes (districts) supported by the SELEVER project. Communes were randomly assigned using restricted randomisation to one of three groups: (1) SELEVER intervention (n = 446 households); (2) SELEVER plus WASH intervention (n = 432 households); and (3) control without intervention (n = 899 households). The study population included women aged 15-49 years with an index child aged 2-4 years. We assessed the effects 1.5-years (WASH substudy) and 3-years (endline) post-intervention on child morbidity and child anthropometry secondary trial outcomes using mixed effects regression models. Participation in intervention activities was low in the SELEVER groups, ranging from 25% at 1.5 years and 10% at endline. At endline, households in the SELEVER groups had higher caregiver knowledge of WASH-livestock risks (∆ = 0.10, 95% confidence interval [CI] [0.04-0.16]) and were more likely to keep children separated from poultry (∆ = 0.09, 95% CI [0.03-0.15]) than in the control group. No differences were found for other hygiene practices, child morbidity symptoms or anthropometry indicators. Integrating livestock WASH interventions alongside poultry and nutrition interventions can increase knowledge of livestock-related risks and improve livestock-hygiene-related practices, yet may not be sufficient to improve the morbidity and nutritional status of young children.


Assuntos
Estado Nutricional , Aves Domésticas , Animais , Humanos , Criança , Feminino , Lactente , Pré-Escolar , Água , Saneamento , Burkina Faso/epidemiologia , Higiene , Morbidade , Antropometria , Gado
5.
Public Health Nutr ; : 1-8, 2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35583048

RESUMO

OBJECTIVE: The study examined the association between depressive symptoms and iron status, anaemia, body weight and pubertal status among Mexican adolescent girls. DESIGN: In this cross-sectional study, depressive symptoms were assessed by the 6-item Kutcher Adolescent Depression Scale, and latent class analysis (LCA) was used to identify and characterise groups of girls based on depressive symptoms. Iron status and inflammation were assessed using ferritin and soluble transferrin receptor, C-reactive protein and alpha-1-acid glycoprotein, respectively. Multiple logistic and linear regressions were applied to model class membership as a function of iron status, anaemia, body weight and pubertal status. PARTICIPANTS: We collected data from 408 girls aged 12-20 years. SETTING: Public schools in northern Mexico. RESULTS: LCA yielded three classes of depressive symptoms: 44·4 % of the adolescents were 'unlikely to be depressed', 41·5 % were 'likely to be depressed' and 14·1 % were 'highly likely to be depressed'. Our analyses demonstrated that iron-deficient girls had greater odds of being 'likely depressed' (OR 2·01, 95 % CI 1·01, 3·00) or 'highly likely depressed' (OR 2·80, 95 % CI 1·76, 3·84). Linear regression analyses revealed that lower Hb concentrations and higher body weight increased the probability of being 'likely depressed'. There was no evidence that depressive symptoms were associated with age at menarche and years since menstruation. CONCLUSIONS: This study shows that iron-deficient adolescent girls are more likely to suffer from depressive symptoms and that lower concentrations of Hb and higher body weight increased the probability of experiencing depressive symptoms.

6.
BMC Med ; 17(1): 146, 2019 07 26.
Artigo em Inglês | MEDLINE | ID: mdl-31345217

RESUMO

BACKGROUND: A recent cohort study among Papua New Guinean women surprisingly showed iron deficiency during pregnancy to be associated with increased birth weight. These findings seemingly contradict previous trial evidence that iron supplementation leads to increased birth weight, particularly in iron-deficient women, and hence require explanation. MAIN TEXT: We have re-analysed data from a previous trial in Kenya and demonstrated that, because women who were initially iron deficient respond better to iron supplementation, they show an increase in birthweight. There is evidence that this benefit is decreased in iron-replete women, possibly due to the adverse effects of haemoconcentration that can impair oxygen and nutrient transfer across the placenta. The Papua New Guinean results might be explained by a similar differential response to the iron supplements that they all received. CONCLUSIONS: Antenatal iron supplementation should ideally be administered in conjunction with measures to prevent, diagnose and treat malaria given the propensity of pathogenic microorganisms to proliferate in iron-supplemented individuals. However, even where services to prevent and treat malaria are poor, current evidence supports the conclusion that the benefits of universal iron supplementation outweigh its risks. Please see related article: https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-018-1146-z. Please see related article: https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-019-1376-8.


Assuntos
Anemia Ferropriva , Malária , Peso ao Nascer , Estudos de Coortes , Suplementos Nutricionais , Feminino , Humanos , Ferro , Quênia , Estudos Longitudinais , Gravidez
7.
Matern Child Nutr ; 15(S5): e12831, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31622044

RESUMO

Home fortification with micronutrient powders (MNP) has been shown to reduce anaemia, with high overall acceptability and adherence, but there is limited evidence from West Africa. Around 80% of children younger than 5 years are anaemic in Mali, and new interventions are needed. This paper reports on the adherence and acceptability of a community-led MNP intervention targeting children aged 6-59 months in Southern Mali. The MNP were delivered by a multidisciplinary group of community volunteers using community-based preschools, cooking demonstrations, and traditional communication networks to promote MNP, nutrition, hygiene, and child stimulation. The MNP were delivered alongside early childhood development interventions and seasonal malaria chemoprevention. Adherence and acceptability were evaluated through two cross-sectional surveys in 2014 and 2016 and a qualitative evaluation in 2015. Over 80% of parents reported ever having given MNP to their child, with 65% having given MNP for four or more days in the last week. Likely contributors to uptake include: perceived positive changes in the children following MNP use, the selection of a food vehicle that was already commonly given to children (morning porridge or bouillie) and the community driven, decentralized and integrated delivery approach. These findings support recommendations from recent reviews of MNP implementation to use community-based delivery approaches and behaviour change components.


Assuntos
Atenção à Saúde/estatística & dados numéricos , Suplementos Nutricionais , Alimentos Fortificados , Fenômenos Fisiológicos da Nutrição do Lactente , Micronutrientes/administração & dosagem , Cooperação do Paciente/estatística & dados numéricos , Pré-Escolar , Análise por Conglomerados , Estudos Transversais , Humanos , Lactente , Mali , Pós , População Rural
8.
Matern Child Nutr ; 15(4): e12818, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-30912287

RESUMO

Poultry production in low income countries provides households with nutrient-rich meat and egg products, as well as cash income. However, traditional production systems present potential health and nutrition risks because poultry scavenging around household compounds may increase children's exposure to livestock-related pathogens. Data from a cross-sectional survey were analysed to examine associations between poultry, water, sanitation, and hygiene practices, and anthropometric indicators in children (6-59 months; n = 3,230) in Burkina Faso. Multilevel regression was used to account for the hierarchical nature of the data. The prevalence of stunting and wasting in children 6-24 months was 19% and 17%, respectively, compared with a prevalence of 26% and 6%, respectively, in children 25-60 months. Over 90% of households owned poultry, and chicken faeces were visible in 70% of compounds. Caregivers reported that 3% of children consumed eggs during a 24-hr recall. The presence of poultry faeces was associated with poultry flock size, poultry-husbandry and household hygiene practices. Having an improved water source and a child visibly clean was associated with higher height-for-age z scores (HAZ). The presence of chicken faeces was associated with lower weight-for-height z scores, and no associations were found with HAZ. Low levels of poultry flock size and poultry consumption in Burkina Faso suggest there is scope to expand production and improve diets in children, including increasing chicken and egg consumption. However, to minimize potential child health risks associated with expanding informal poultry production, research is required to understand the mechanisms through which cohabitation with poultry adversely affects child health and design interventions to minimize these risks.


Assuntos
Criação de Animais Domésticos/estatística & dados numéricos , Higiene , Aves Domésticas , Saneamento/estatística & dados numéricos , Abastecimento de Água/estatística & dados numéricos , Animais , Antropometria , Burkina Faso , Pré-Escolar , Dieta/estatística & dados numéricos , Feminino , Transtornos do Crescimento , Humanos , Lactente , Masculino , Estado Nutricional , População Rural/estatística & dados numéricos , Saneamento/normas , Abastecimento de Água/normas
9.
BMC Med ; 16(1): 7, 2018 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-29353552

RESUMO

In 2016, the World Health Organization (WHO) recommended point-of-use fortification of complementary foods with iron-containing micronutrient powders to improve iron status and reduce anaemia in children at risk of anaemia. This recommendation continues to be debated. In a recent trial among Kenyan children aged 12-36 months, we found no evidence that daily point-of-use fortification was efficacious in improving haemoglobin concentration or plasma iron markers. An updated meta-analysis indicated that, on average, in an arbitrarily selected setting and with adherence as obtained under trial conditions, one may expect a small increase in haemoglobin concentration in preschool children, with the upper limit of the 95% CI virtually excluding an effect beyond 5.5 g/L. In the present paper, we elaborate on the interpretation of these findings and the meta-analyses that formed the basis for the WHO guidelines. In particular, we draw attention to the phenomenon that small group differences in the distribution of continuous outcomes (haemoglobin concentration, ferritin concentrations) can give a false impression of relatively large effects on the prevalence of the dichotomised outcomes (anaemia, iron deficiency).Please see related articles: https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-017-0839-z , https://bmcmedicine.biomedcentral.com/articles/10.1186/s12916-017-0867-8.


Assuntos
Anemia Ferropriva/sangue , Micronutrientes/deficiência , Anemia/sangue , Suplementos Nutricionais , Alimentos Fortificados , Hemoglobinas , Humanos , Quênia/epidemiologia , Pós
10.
Public Health Nutr ; 21(2): 365-376, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-28965533

RESUMO

OBJECTIVE: Introduction of biofortified cassava as school lunch can increase vitamin A intake, but may increase risk of other deficiencies due to poor nutrient profile of cassava. We assessed the potential effect of introducing a yellow cassava-based school lunch combined with additional food-based recommendations (FBR) on vitamin A and overall nutrient adequacy using Optifood (linear programming tool). DESIGN: Cross-sectional study to assess dietary intakes (24 h recall) and derive model parameters (list of foods consumed, median serving sizes, food and food (sub)group frequency distributions, food cost). Three scenarios were modelled, namely daily diet including: (i) no school lunch; (ii) standard 5d school lunch with maize/beans; and (iii) 5d school lunch with yellow cassava. Each scenario and scenario 3 with additional FBR were assessed on overall nutrient adequacy using recommended nutrient intakes (RNI). SETTING: Eastern Kenya. SUBJECTS: Primary-school children (n 150) aged 7-9 years. RESULTS: Best food pattern of yellow cassava-based lunch scenario achieved 100 % RNI for six nutrients compared with no lunch (three nutrients) or standard lunch (five nutrients) scenario. FBR with yellow cassava and including small dried fish improved nutrient adequacy, but could not ensure adequate intake of fat (52 % of average requirement), riboflavin (50 % RNI), folate (59 % RNI) and vitamin A (49 % RNI). CONCLUSIONS: Introduction of yellow cassava-based school lunch complemented with FBR potentially improved vitamin A adequacy, but alternative interventions are needed to ensure dietary adequacy. Optifood is useful to assess potential contribution of a biofortified crop to nutrient adequacy and to develop additional FBR to address remaining nutrient gaps.


Assuntos
Dieta , Manihot/química , Programação Linear , Recomendações Nutricionais , Adolescente , Criança , Pré-Escolar , Estudos Transversais , Gorduras na Dieta/administração & dosagem , Feminino , Ácido Fólico/administração & dosagem , Serviços de Alimentação , Humanos , Quênia , Almoço , Masculino , Rememoração Mental , Micronutrientes/administração & dosagem , Micronutrientes/sangue , Avaliação Nutricional , Valor Nutritivo , Riboflavina/administração & dosagem , Instituições Acadêmicas , Tamanho da Porção de Referência , Vitamina A/administração & dosagem , Vitamina A/sangue
11.
BMC Public Health ; 18(1): 205, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29391008

RESUMO

BACKGROUND: The efficacy of home fortification with iron-containing micronutrient powders varies between trials, perhaps in part due to population differences in adherence. We aimed to assess to what extent adherence measured by sachet count or self-reporting forms is in agreement with adherence measured by electronic device. In addition, we explored how each method of adherence assessment (electronic device, sachet count, self-reporting forms) is associated with haemoglobin concentration measured at the end of intervention; and to what extent baseline factors were associated with adherence as measured by electronic device. METHODS: Three hundred thirty-eight rural Kenyan children aged 12-36 months were randomly allocated to three treatment arms (home fortification with two different iron formulations or placebo). Home fortificants were administered daily by parents or guardians over a 30 day-intervention period. We assessed adherence using an electronic device that stores and provides information of the time and day of opening of the container that was used to store the fortificants sachets in each child's residence. In addition, we assessed adherence by self-reporting and sachet counts. We also measured haemoglobin concentration at the end of intervention. RESULTS: Adherence, defined as having received at least 24 sachets (≥ 80%), during the 30-day intervention period was attained by only 60.6% of children as assessed by the electronic device. The corresponding values were higher when adherence was assessed by self-report (83.9%; difference: 23.3%, 95% CI: 18.8% to 27.8%) or sachet count (86.3%; difference: 25.7%, 95% CI: 21.0% to 30.4%). Among children who received iron, each 10 openings of the electronic cap of the sachet storage container were associated with an increase in haemoglobin concentration at the end of intervention by 1.2 g/L (95% CI: 0.0 to 1.9 g/L). Adherence was associated with the age of the parent but not with intervention group; with age, sex or anthropometric indices of the child; or with age or sex of the parent or guardian. CONCLUSIONS: The use of self -reporting and sachet count may lead to overestimates of adherence to home fortification. TRIAL REGISTRATION: The trial was registered with ClinicalTrials.gov ( NCT02073149 ) on 25 February 2014.


Assuntos
Coleta de Dados/métodos , Alimentos Fortificados , Ferro/uso terapêutico , Adesão à Medicação/estatística & dados numéricos , Micronutrientes/uso terapêutico , Anemia Ferropriva/prevenção & controle , Pré-Escolar , Feminino , Humanos , Lactente , Quênia , Masculino , Monitorização Fisiológica/instrumentação , Pós , Reprodutibilidade dos Testes , População Rural/estatística & dados numéricos , Autorrelato
12.
Br J Haematol ; 177(6): 884-895, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28272734

RESUMO

The World Health Organization recommends universal iron supplementation of 30-60 mg/day in pregnancy but coverage is low in most countries. Its efficacy is uncertain, however, and there has been a vigorous debate in the last decade about its safety, particularly in areas with a high burden of malaria and other infectious diseases. We reviewed the evidence on the safety and efficacy of antenatal iron supplementation in low-income countries. We found no evidence that daily supplementation at a dose of 60 mg leads to increased maternal Plasmodium infection risk. On the other hand, recent meta-analyses found that antenatal iron supplementation provides benefits for maternal health (severe anaemia at postpartum, blood transfusion). For neonates, there was a reduced prematurity risk, and only a small or no effect on birth weight. A recent trial showed, however, that benefits of antenatal iron supplementation on maternal and neonatal health vary by maternal iron status, with substantial benefits in iron-deficient women. The benefits of universal iron supplementation are likely to vary with the prevalence of iron deficiency. As a consequence, the balance between benefits and risks is probably more favourable in low-income countries than in high-income countries despite the higher exposure to infectious pathogens.


Assuntos
Anemia Ferropriva/prevenção & controle , Suplementos Nutricionais , Ferro/uso terapêutico , Complicações Hematológicas na Gravidez/prevenção & controle , Cuidado Pré-Natal/métodos , Anemia Ferropriva/complicações , Países em Desenvolvimento , Suplementos Nutricionais/efeitos adversos , Feminino , Humanos , Ferro/efeitos adversos , Ferro/fisiologia , Malária/etiologia , Malária/transmissão , Estresse Oxidativo/fisiologia , Gravidez , Complicações Parasitárias na Gravidez/etiologia
13.
Br J Haematol ; 177(6): 905-918, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28369746

RESUMO

For decades, folic acid has routinely been given to prevent or treat anaemia in children, pregnant women and people with sickle cell disease. However, there is no conclusive evidence that folate deficiency anaemia constitutes a public health problem in any of these groups. Industrial flour fortification is recommended and implemented in many countries to combat neural tube defects. Dietary folates or folic acid can antagonise the action of antifolate drugs that play a critical role in the prevention and treatment of malaria. Randomised trials have shown that folic acid supplementation increases the rate of treatment failures with sulfadoxine-pyrimethamine. The efficacy of antifolate drugs against Plasmodium is maximized in the absence of exogenous folic acid, suggesting that there is no safe minimum dose of ingested folic acid. We here review the safety and benefits of interventions to increase folate status in malaria-endemic countries. We conclude that formal cost-benefit analyses are required.


Assuntos
Suplementos Nutricionais , Ácido Fólico/uso terapêutico , Malária/prevenção & controle , Antimaláricos/uso terapêutico , Suplementos Nutricionais/efeitos adversos , Interações Medicamentosas , Resistência a Medicamentos , Feminino , Ácido Fólico/efeitos adversos , Ácido Fólico/fisiologia , Antagonistas do Ácido Fólico/uso terapêutico , Deficiência de Ácido Fólico/prevenção & controle , Humanos , Gravidez , Complicações na Gravidez/prevenção & controle
14.
BMC Med ; 15(1): 89, 2017 04 28.
Artigo em Inglês | MEDLINE | ID: mdl-28449690

RESUMO

BACKGROUND: We aimed to show the non-inferiority of home fortification with a daily dose of 3 mg iron in the form of iron as ferric sodium ethylenediaminetetraacetate (NaFeEDTA) compared with 12.5 mg iron as encapsulated ferrous fumarate in Kenyan children aged 12-36 months. In addition, we updated a recent meta-analysis to assess the efficacy of home fortification with iron-containing powders, with a view to examining diversity in trial results. METHODS: We gave chemoprevention by dihydroartemisinin-piperaquine, albendazole and praziquantel to 338 afebrile children with haemoglobin concentration ≥70 g/L. We randomly allocated them to daily home fortification for 30 days with either placebo, 3 mg iron as NaFeEDTA or 12.5 mg iron as encapsulated ferrous fumarate. We assessed haemoglobin concentration (primary outcome), plasma iron markers, plasma inflammation markers and Plasmodium infection in samples collected at baseline and after 30 days of intervention. We conducted a meta-analysis of randomised controlled trials in pre-school children to assess the effect of home fortification with iron-containing powders on anaemia and haemoglobin concentration at end of intervention. RESULTS: A total of 315 children completed the 30-day intervention period. At baseline, 66.9% of children had inflammation (plasma C-reactive protein concentration >5 mg/L or plasma α 1-acid glycoprotein concentration >1.0 g/L); in those without inflammation, 42.5% were iron deficient. There was no evidence, either in per protocol analysis or intention-to-treat analysis, that home fortification with either of the iron interventions improved haemoglobin concentration, plasma ferritin concentration, plasma transferrin receptor concentration or erythrocyte zinc protoporphyrin-haem ratio. We also found no evidence of effect modification by iron status, anaemia status and inflammation status at baseline. In the meta-analysis, the effect on haemoglobin concentration was highly heterogeneous between trials (I 2: 84.1%; p value for test of heterogeneity: <0.0001). CONCLUSIONS: In this population, home fortification with either 3 mg iron as NaFeEDTA or 12.5 mg iron as encapsulated ferrous fumarate was insufficiently efficacious to assess non-inferiority of 3 mg iron as NaFeEDTA compared to 12.5 mg iron as encapsulated ferrous fumarate. Our finding of heterogeneity between trial results should stimulate subgroup analysis or meta-regression to identify population-specific factors that determine efficacy. TRIAL REGISTRATION: The trial was registered with ClinicalTrials.gov ( NCT02073149 ) on 25 February 2014.


Assuntos
Anemia Ferropriva/prevenção & controle , Compostos Férricos/uso terapêutico , Compostos Ferrosos/uso terapêutico , Alimentos Fortificados , Anemia Ferropriva/sangue , Proteína C-Reativa , Pré-Escolar , Método Duplo-Cego , Ácido Edético/uso terapêutico , Feminino , Ferritinas , Humanos , Lactente , Ferro/sangue , Quênia/epidemiologia , Malária , Masculino
15.
J Infect Dis ; 211(7): 1128-33, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25344520

RESUMO

In malaria-endemic areas, Plasmodium falciparum parasitemia is common in apparently healthy children and severe malaria is commonly misdiagnosed in patients with incidental parasitemia. We assessed whether the plasma Plasmodium falciparum DNA concentration is a useful datum for distinguishing uncomplicated from severe malaria in African children and Asian adults. P. falciparum DNA concentrations were measured by real-time polymerase chain reaction (PCR) in 224 African children (111 with uncomplicated malaria and 113 with severe malaria) and 211 Asian adults (100 with uncomplicated malaria and 111 with severe malaria) presenting with acute falciparum malaria. The diagnostic accuracy of plasma P. falciparum DNA concentrations in identifying severe malaria was 0.834 for children and 0.788 for adults, similar to that of plasma P. falciparum HRP2 levels and substantially superior to that of parasite densities (P < .0001). The diagnostic accuracy of plasma P. falciparum DNA concentrations plus plasma P. falciparum HRP2 concentrations was significantly greater than that of plasma P. falciparum HRP2 concentrations alone (0.904 for children [P = .004] and 0.847 for adults [P = .003]). Quantitative real-time PCR measurement of parasite DNA in plasma is a useful method for diagnosing severe falciparum malaria on fresh or archived plasma samples.


Assuntos
DNA de Protozoário/sangue , Malária Falciparum/diagnóstico , Plasmodium falciparum/isolamento & purificação , Adulto , Animais , Bangladesh/epidemiologia , Pré-Escolar , Diagnóstico Diferencial , Feminino , Humanos , Índia/epidemiologia , Lactente , Estudos Longitudinais , Malária Falciparum/epidemiologia , Malária Falciparum/parasitologia , Masculino , Moçambique/epidemiologia , Parasitemia , Plasmodium falciparum/genética , Curva ROC , Reação em Cadeia da Polimerase em Tempo Real/métodos , Índice de Gravidade de Doença , Tanzânia/epidemiologia , Adulto Jovem
16.
BMC Med ; 13: 30, 2015 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-25856672

RESUMO

BACKGROUND: Serum retinol concentration determined by high-performance liquid chromatography (HPLC) is recommended by the World Health Organization to assess population vitamin A status. This assay is expensive, technically demanding and rarely available in developing countries. Our objective was a) to assess the diagnostic performance of proxy markers in detecting vitamin A deficiency and b) to derive decision rules based on these markers to estimate vitamin A deficiency prevalence. METHODS: A survey was conducted in 15 rural primary schools in Eastern Province, Kenya, with 375 children aged 6 to 12 years (25 randomly selected per school). Serum retinol concentration <0.70 µmol/L by HPLC was used to define vitamin A deficiency. Proxy markers for vitamin A deficiency were serum concentrations of retinol binding protein (RBP), transthyretin, retinol measured by fluorometry and RBP:transthyretin molar ratio. RESULTS: The prevalence of vitamin A deficiency (HPLC) was 18%. Transthyretin and RBP showed the best diagnostic performance individually, with area-under-the-curve (AUC) values of 0.96 and 0.93. When combined, and with C-reactive protein added, the AUC increased to 0.98. A simple decision rule {(-15.277 × [RBP, µmol/L] - 7.013 × [Transthyretin, µmol/L] + 0.367 × [C-reactive protein, mg/L] + 24.714) > 0.496} yielded prevalence estimates of vitamin A deficiency that is unbiased by diagnostic error. CONCLUSIONS: The combination of transthyretin, RBP and C-reactive protein concentrations could eventually replace retinol concentration by HPLC in resource-poor settings as the preferred method to assess the population burden of vitamin A deficiency.


Assuntos
Biomarcadores/sangue , Proteínas de Ligação ao Retinol/análise , Deficiência de Vitamina A/diagnóstico , Deficiência de Vitamina A/epidemiologia , Vitamina A/sangue , Área Sob a Curva , População Negra , Proteína C-Reativa/análise , Criança , Cromatografia Líquida de Alta Pressão , Estudos Transversais , Feminino , Fluorometria , Humanos , Imunoensaio , Quênia/epidemiologia , Masculino , Sistemas Automatizados de Assistência Junto ao Leito , Prevalência
17.
Malar J ; 14: 249, 2015 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-26088606

RESUMO

BACKGROUND: Tumour necrosis factor (TNF) is central to the immune response to Plasmodium infection. Its plasma concentration is influenced by allele variants in the promoter region of TNF. The study's objectives were to assess TNF allele variants (TNF(-1031), TNF(-308)): (1) modulation of malaria rates in young Tanzanian children; (2) modulation of the severity of malaria as indicated by haemoglobin concentrations at the time of presentation with febrile episodes; and (3) the association between Plasmodium infection and haemoglobin concentration in symptomless parasite carriers. METHODS: Data from a placebo-controlled trial in which 612 Tanzanian children aged 6-60 months with height-for-age z-score in the range -3 SD to 1.5 SD was utilised. Those with Plasmodium infection at baseline were treated with artemether-lumefantrine. An episode of malaria was predefined as current Plasmodium infection with an inflammatory response (axillary temperature ≥37.5°C or whole blood C-reactive protein concentration ≥8 mg/L) in children reported sick. Linkage disequilibrium (LD) pattern assessment as well as haplotype analysis was conducted using HAPLOVIEW. Cox regression models used in the primary analysis accounted for multiple episodes per child. RESULTS: Genotyping of 94.9% (581/612) children for TNF(-1031) (TNF(-1031)T>C); allele frequency was 0.39. Corresponding values for rs1800629 (TNF(-308)G>A) were 95.4% (584/612) and 0.17. Compared to the wild type genotype (TT), malaria rates were increased in the TNF -1031CC genotype (hazard ratio, HR [95% CI]: 1.41 [1.01‒1.97] and 1.31 [0.97‒1.76] for crude analysis and adjusting for pre-specified baseline factors, respectively) but decreased in those with the TNF(-308)AA genotype (corresponding HR: 0.13 [0.02‒0.63] and 0.16 [0.04‒0.67]). These associations were weaker when analysing first episodes of malaria (P value -0.59 and 0.38, respectively). No evidence that allele variants of TNF(-1031) and TNF(-308) affected haemoglobin concentration at first episode of malaria, or that they modified the association between Plasmodium infection and haemoglobin concentrations at baseline was observed. CONCLUSION: In this cohort of Tanzanian children, the TNF (-1031)CC genotype was associated with increased rates of malarial episodes, whereas the TNF(-308)AA genotype was associated with decreased rates.


Assuntos
Frequência do Gene , Hemoglobinas/análise , Malária/parasitologia , Plasmodium/fisiologia , Fator de Necrose Tumoral alfa/genética , Infecções Assintomáticas/epidemiologia , Pré-Escolar , Feminino , Humanos , Lactente , Estudos Longitudinais , Malária/epidemiologia , Masculino , Tanzânia/epidemiologia , Fator de Necrose Tumoral alfa/metabolismo
18.
JAMA ; 314(10): 1009-20, 2015 Sep 08.
Artigo em Inglês | MEDLINE | ID: mdl-26348751

RESUMO

IMPORTANCE: Anemia affects most pregnant African women and is predominantly due to iron deficiency, but antenatal iron supplementation has uncertain health benefits and can increase the malaria burden. OBJECTIVE: To measure the effect of antenatal iron supplementation on maternal Plasmodium infection risk, maternal iron status, and neonatal outcomes. DESIGN, SETTING, AND PARTICIPANTS: Randomized placebo-controlled trial conducted October 2011 through April 2013 in a malaria endemic area among 470 rural Kenyan women aged 15 to 45 years with singleton pregnancies, gestational age of 13 to 23 weeks, and hemoglobin concentration of 9 g/dL or greater. All women received 5.7 mg iron/day through flour fortification during intervention, and usual intermittent preventive treatment against malaria was given. INTERVENTIONS: Supervised daily supplementation with 60 mg of elemental iron (as ferrous fumarate, n = 237 women) or placebo (n = 233) from randomization until 1 month postpartum. MAIN OUTCOMES AND MEASURES: Primary outcome was maternal Plasmodium infection at birth. Predefined secondary outcomes were birth weight and gestational age at delivery, intrauterine growth, and maternal and infant iron status at 1 month after birth. RESULTS: Among the 470 participating women, 40 women (22 iron, 18 placebo) were lost to follow-up or excluded at birth; 12 mothers were lost to follow-up postpartum (5 iron, 7 placebo). At baseline, 190 of 318 women (59.7%) were iron-deficient. In intention-to-treat analysis, comparison of women who received iron vs placebo, respectively, yielded the following results at birth: Plasmodium infection risk: 50.9% vs 52.1% (crude difference, -1.2%, 95% CI, -11.8% to 9.5%; P = .83); birth weight: 3202 g vs 3053 g (crude difference, 150 g, 95% CI, 56 to 244; P = .002); birth-weight-for-gestational-age z score: 0.52 vs 0.31 (crude difference, 0.21, 95% CI, -0.11 to 0.52; P = .20); and at 1 month after birth: maternal hemoglobin concentration: 12.89 g/dL vs 11.99 g/dL (crude difference, 0.90 g/dL, 95% CI, 0.61 to 1.19; P < .001); geometric mean maternal plasma ferritin concentration: 32.1 µg/L vs 14.4 µg/L (crude difference, 123.4%, 95% CI, 85.5% to 169.1%; P < .001); geometric mean neonatal plasma ferritin concentration: 163.0 µg/L vs 138.7 µg/L (crude difference, 17.5%, 95% CI, 2.4% to 34.8%; P = .02). Serious adverse events were reported for 9 and 12 women who received iron and placebo, respectively. There was no evidence that intervention effects on Plasmodium infection risk were modified by intermittent preventive treatment use. CONCLUSIONS AND RELEVANCE: Among rural Kenyan women with singleton pregnancies, administration of daily iron supplementation, compared with administration of placebo, resulted in no significant differences in overall maternal Plasmodium infection risk. Iron supplementation led to increased birth weight. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01308112.


Assuntos
Suplementos Nutricionais/efeitos adversos , Compostos Ferrosos/administração & dosagem , Ferro/efeitos adversos , Malária Falciparum/etiologia , Complicações Parasitárias na Gravidez/etiologia , Cuidado Pré-Natal , Adolescente , Adulto , Peso ao Nascer , Feminino , Idade Gestacional , Hemoglobina A/análise , Humanos , Ferro/administração & dosagem , Quênia , Malária Falciparum/prevenção & controle , Gravidez , Complicações Parasitárias na Gravidez/prevenção & controle , População Rural
19.
BMC Med ; 12: 229, 2014 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-25428714

RESUMO

BACKGROUND: Iron-deficient erythropoiesis results in excess formation of zinc protoporphyrin (ZPP), which can be measured instantly and at low assay cost using portable haematofluorometers. ZPP is used as a screening marker of iron deficiency in individual pregnant women and children, but also to assess population iron status in combination with haemoglobin concentration. We examined associations between ZPP and disorders that are common in Africa. In addition, we assessed the diagnostic utility of ZPP (measured in whole blood and erythrocytes), alone or in combination with haemoglobin concentration, in detecting iron deficiency (plasma ferritin concentration <15 µg/L). METHODS: Single blood samples were collected from a population sample of 470 rural Kenyan women with singleton pregnancies, gestational age 13 to 23 weeks, and haemoglobin concentration ≥90 g/L. We used linear regression analysis to assess associations between ZPP and iron markers (including anaemia), factors known or suspected to be associated with iron status, inflammation markers (plasma concentrations of C-reactive protein and α 1-acid glycoprotein), infections (Plasmodium infection, HIV infection), and other disorders (α(+)-thalassaemia, plasma concentrations of total bilirubin, and lactate dehydrogenase). Subsequently, in those without inflammation, Plasmodium infection, or HIV infection, we used logistic discriminant analysis and examined receiver operating characteristics curves with corresponding area-under-the-curve to assess diagnostic performance of ZPP, alone and in combination with haemoglobin concentration. RESULTS: Individually, whole blood ZPP, erythrocyte ZPP, and erythrocyte protoporphyrin had limited ability to discriminate between women with and without iron deficiency. Combining each of these markers with haemoglobin concentration had no additional diagnostic value. Conventional cut off points for whole blood ZPP (>70 µmol/mol haem) resulted in gross overestimates of the prevalence of iron deficiency. CONCLUSIONS: Erythrocyte ZPP has limited value to rule out iron deficiency when used for screening in conditions with a low prevalence (e.g., 10%). ZPP is of unreliable diagnostic utility when discriminating between pregnant women with and without iron deficiency. Based on these findings, guidelines on the use of ZPP to assess iron status in individuals or populations of pregnant women need review. TRIAL REGISTRATION: NCT01308112 (2 March 2011).


Assuntos
Anemia Ferropriva/diagnóstico , Complicações na Gravidez/diagnóstico , Gravidez , Protoporfirinas/sangue , Adolescente , Adulto , Anemia Ferropriva/sangue , Biomarcadores/sangue , Eritrócitos/química , Feminino , Humanos , Quênia , Complicações na Gravidez/sangue , Curva ROC , Análise de Regressão
20.
Blood ; 119(8): 1922-8, 2012 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-22228627

RESUMO

Iron supplementation strategies in the developing world remain controversial because of fears of exacerbating prevalent infectious diseases. Understanding the conditions in which iron will be absorbed and incorporated into erythrocytes is therefore important. We studied Gambian children with either postmalarial or nonmalarial anemia, who were given oral iron supplements daily for 30 days. Supplements administered on days 1 and 15 contained the stable iron isotopes (57)Fe and (58)Fe, respectively, and erythrocyte incorporation was measured in blood samples drawn 14 days later. We investigated how the iron-regulatory hormone hepcidin and other inflammatory/iron-related indices, all measured on the day of isotope administration, correlated with erythrocyte iron incorporation. In univariate analyses, hepcidin, ferritin, C-reactive protein, and soluble transferrin receptor (sTfR) strongly predicted incorporation of (57)Fe given on day 1, while hepcidin, ferritin, and sTfR/log ferritin correlated with (58)Fe incorporation. In a final multivariate model, the most consistent predictor of erythrocyte isotope incorporation was hepcidin. We conclude that under conditions of competing signals (anemia, iron deficiency, and infection), hepcidin powerfully controls use of dietary iron. We suggest that low-cost point-of-care hepcidin assays would aid iron supplementation programs in the developing world.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Peptídeos Catiônicos Antimicrobianos/sangue , Eritrócitos/metabolismo , Ferro da Dieta/uso terapêutico , Anemia Ferropriva/sangue , Anemia Ferropriva/complicações , Antimaláricos/uso terapêutico , Proteína C-Reativa/metabolismo , Pré-Escolar , Esquema de Medicação , Ensaio de Imunoadsorção Enzimática , Ferritinas/sangue , Gâmbia , Hepcidinas , Humanos , Lactente , Isótopos de Ferro , Ferro da Dieta/administração & dosagem , Malária Falciparum/complicações , Malária Falciparum/tratamento farmacológico , Análise Multivariada , Valor Preditivo dos Testes , Receptores da Transferrina/sangue , Fatores de Tempo , Resultado do Tratamento
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