RESUMO
BACKGROUND: Adolescents are considered at high risk of developing iron deficiency. Studies in children indicate that the prevalence of iron deficiency increased with malaria transmission, suggesting malaria seasonally may drive iron deficiency. This paper examines monthly seasonal infection patterns of malaria, abnormal vaginal flora, chorioamnionitis, antibiotic and antimalarial prescriptions, in relation to changes in iron biomarkers and nutritional indices in adolescents living in a rural area of Burkina Faso, in order to assess the requirement for seasonal infection control and nutrition interventions. METHODS: Data collected between April 2011 and January 2014 were available for an observational seasonal analysis, comprising scheduled visits for 1949 non-pregnant adolescents (≤19 years), (315 of whom subsequently became pregnant), enrolled in a randomised trial of periconceptional iron supplementation. Data from trial arms were combined. Body Iron Stores (BIS) were calculated using an internal regression for ferritin to allow for inflammation. At recruitment 11% had low BIS (< 0 mg/kg). Continuous outcomes were fitted to a mixed-effects linear model with month, age and pregnancy status as fixed effect covariates and woman as a random effect. Dichotomous infection outcomes were fitted with analogous logistic regression models. RESULTS: Seasonal variation in malaria parasitaemia prevalence ranged between 18 and 70% in non-pregnant adolescents (P < 0.001), peaking at 81% in those who became pregnant. Seasonal variation occurred in antibiotic prescription rates (0.7-1.8 prescriptions/100 weekly visits, P < 0.001) and chorioamnionitis prevalence (range 15-68%, P = 0.026). Mucosal vaginal lactoferrin concentration was lower at the end of the wet season (range 2-22 µg/ml, P < 0.016), when chorioamnionitis was least frequent. BIS fluctuated annually by up to 53.2% per year around the mean BIS (5.1 mg/kg2, range 4.1-6.8 mg/kg), with low BIS (< 0 mg/kg) of 8.7% in the dry and 9.8% in the wet seasons (P = 0.36). Median serum transferrin receptor increased during the wet season (P < 0.001). Higher hepcidin concentration in the wet season corresponded with rising malaria prevalence and use of prescriptions, but with no change in BIS. Mean Body Mass Index and Mid-Upper-Arm-Circumference values peaked mid-dry season (both P < 0.001). CONCLUSIONS: Our analysis supports preventive treatment of malaria among adolescents 15-19 years to decrease their disease burden, especially asymptomatic malaria. As BIS were adequate in most adolescents despite seasonal malaria, a requirement for programmatic iron supplementation was not substantiated.
Assuntos
Ferro , Malária , Adolescente , Burkina Faso/epidemiologia , Criança , Feminino , Humanos , Malária/tratamento farmacológico , Malária/epidemiologia , Gravidez , Estações do Ano , VaginaRESUMO
This study in Burkina Faso investigated whether offspring of young mothers who had received weekly periconceptional iron supplementation in a randomised controlled trial were at increased risk of malaria. A child safety survey was undertaken in the peak month of malaria transmission towards the end of the trial to assess child iron biomarkers, nutritional status, anaemia and malaria outcomes. Antenatal iron biomarkers, preterm birth, fetal growth restriction and placental pathology for malaria and chorioamnionitis were assessed. Data were available for 180 babies surviving to the time of the survey when their median age was 9 months. Prevalence of maternal iron deficiency in the last trimester based on low body iron stores was 16%. Prevalence of active placental malaria infection was 24.8%, past infection 59% and chorioamnionitis 55.6%. Babies of iron supplemented women had lower median gestational age. Four out of five children ≥ 6 months were iron deficient, and 98% were anaemic. At 4 months malaria prevalence was 45%. Child iron biomarkers, anaemia and malaria outcomes did not differ by trial arm. Factors associated with childhood parasitaemia were third trimester C-reactive protein level (OR 2.1; 95% CI 1.1-3.9), active placental malaria (OR 5.8; 1.0-32.5, P = 0.042) and child body iron stores (OR 1.13; 1.04-1.23, P = 0.002). Chorioamnionitis was associated with reduced risk of child parasitaemia (OR 0.4; 0.1-1.0, P = 0.038). Periconceptional iron supplementation of young women did not alter body iron stores of their children. Higher child body iron stores and placental malaria increased risk of childhood parasitaemia.
Assuntos
Malária , Nascimento Prematuro , Burkina Faso , Criança , Pré-Escolar , Suplementos Nutricionais , Feminino , Ácido Fólico , Humanos , Lactente , Recém-Nascido , Ferro , Malária/epidemiologia , Malária/prevenção & controle , Placenta , GravidezRESUMO
High levels of storage iron may increase malaria susceptibility. This risk has not been investigated in semi-immune adolescents. We investigated whether baseline iron status of non-pregnant adolescent girls living in a high malaria transmission area in Burkina Faso affected malaria risk during the following rainy season. For this prospective study, we analysed data from an interim safety survey, conducted six months into a randomised iron supplementation trial. We used logistic regression to model the risk of P. falciparum infection prevalence by microscopy, the pre-specified interim safety outcome, in relation to iron status, nutritional indicators and menarche assessed at recruitment. The interim survey was attended by 1223 (82%) of 1486 eligible participants, 1084 (89%) of whom were <20 years at baseline and 242 (22%) were pre-menarcheal. At baseline, prevalence of low body iron stores was 10%. At follow-up, 38% of adolescents had predominantly asymptomatic malaria parasitaemias, with no difference by menarcheal status. Higher body iron stores at baseline predicted an increased malaria risk in the following rainy season (OR 1.18 (95% CI 1.05, 1.34, p = 0.007) after adjusting for bed net use, age, menarche, and body mass index. We conclude that routine iron supplementation should not be recommended without prior effective malaria control.
Assuntos
Ferro/sangue , Malária Falciparum/epidemiologia , Malária Falciparum/etiologia , Estado Nutricional , Adolescente , Burkina Faso , Método Duplo-Cego , Feminino , Humanos , Modelos Logísticos , Prevalência , Estudos Prospectivos , Chuva , Fatores de Risco , Estações do AnoRESUMO
BACKGROUND & AIMS: Low iron stores may protect from malaria infection, therefore improving iron stores in early pregnancy in line with current recommendations could increase malaria susceptibility. To test this hypothesis we compared iron biomarkers and red cell indices in nulliparae and primigravidae who participated in a randomized controlled trial of long-term weekly iron supplementation. METHODS: Cross-sectional and longitudinal data analysis from a randomized controlled trial of long-term weekly iron supplementation in rural Burkina Faso. Malaria parasitaemia was monitored and biomarkers and red cell indices measured at study end-points: plasma ferritin, transferrin receptor (sTfR), zinc protoporphyrin, hepcidin, sTfR/log10 ferritin ratio, body iron, haemoglobin, red cell distribution width; mean corpuscular haemoglobin concentration/volume, and C-reactive protein. Correlation coefficients between biomarkers and red cell indices were determined. A regression correction approach based on ferritin was used to estimate iron body stores, allowing for inflammation. Body iron differences were compared between nulliparae and primigravidae, and the association determined of iron biomarkers and body iron stores with malaria. RESULTS: Iron and haematological indices of 972 nulliparae (mean age 16.5 years) and 314 primigravidae (median gestation 18 weeks) were available. Malaria prevalence was 54.0% in primigravidae and 41.8% in nulliparae (relative risk 1.28, 95% CI 1.13-1.45, P < 0.001), anaemia prevalence 69.7% and 43.4% (P < 0.001), and iron deficient erythropoiesis (low body iron) 8.0% and 11.7% (P = 0.088) respectively. Unlike other biomarkers the sTfR/log10 ferritin ratio showed no correlation with inflammation as measured by CRP. Most biomarkers indicated reduced iron deficiency in early pregnancy, with the exception of haemoglobin. Body iron increased by 0.6-1.2 mg/kg in early gestation, did not differ by malaria status in nulliparae, but was higher in primigravidae with malaria (6.5 mg/kg versus 5.0 mg/kg; relative risk 1.53, 95% CI 0.67-2.38, P < 0.001). CONCLUSION: In primigravidae, early pregnancy haemoglobin was not a good indicator of requirement for iron supplementation, which could be detrimental given the association of better iron status with increased malaria infection. TRIAL REGISTRATION: clinicaltrials.gov:NCT01210040. Until placed in a public repository, data relating to the current study can be requested from the corresponding author and will be made available following an end user data agreement and sponsor approval.
Assuntos
Anemia Ferropriva/sangue , Anemia Ferropriva/epidemiologia , Ferro/sangue , Malária/sangue , Malária/epidemiologia , Adolescente , Adulto , Biomarcadores , Burkina Faso/epidemiologia , Estudos Transversais , Feminino , Número de Gestações , Humanos , Estudos Longitudinais , Gravidez , Primeiro Trimestre da Gravidez , Prevalência , Adulto JovemRESUMO
BACKGROUND: In view of recent evidence from a randomized trial in Burkina Faso that periconceptional iron supplementation substantially increases risk of spontaneous preterm birth (< 37 weeks) in first pregnancies (adjusted relative risk = 2.22; 95% CI 1.39-3.61), explanation is required to understand potential mechanisms, including progesterone mediated responses, linking long-term iron supplementation, malaria and gestational age. METHODS: The analysis developed a model based on a dual hit inflammatory mechanism arising from simultaneous malaria and gut infections, supported in part by published trial results. This model is developed to understand mechanisms linking iron supplementation, malaria and gestational age. Background literature substantiates synergistic inflammatory effects of these infections where trial data is unavailable. A path modelling exercise assessed direct and indirect paths influencing preterm birth and gestation length. RESULTS: A dual hit hypothesis incorporates two main pathways for pro-inflammatory mechanisms, which in this model, interact to increase hepcidin expression. Trial data showed preterm birth was positively associated with C-reactive protein (P = 0.0038) an inflammatory biomarker. The malaria pathway upregulates C-reactive protein and serum hepcidin, thereby reducing iron absorption. The enteric pathway results from unabsorbed gut iron, which induces microbiome changes and pathogenic gut infections, initiating pro-inflammatory events with lipopolysaccharide expression. Data from the trial suggest that raised hepcidin concentration is a mediating catalyst, being inversely associated with shorter gestational age at delivery (P = 0.002) and positively with preterm incidence (P = 0.007). A segmented regression model identified a change-point consisting of two segments before and after a sharp rise in hepcidin concentration. This showed a post change hepcidin elevation in women with increasing C-reactive protein values in late gestation (post-change slope 0.55. 95% CI 0.39-0.92, P < 0.001). Path modelling confirmed seasonal malaria effects on preterm birth, with mediation through C-reactive protein and (non-linear) hepcidin induction. CONCLUSIONS: Following long-term iron supplementation, dual inflammatory pathways that mediate hepcidin expression and culminate in progesterone withdrawal may account for the reduction in gestational age observed in first pregnancies in this area of high malaria exposure. If correct, this model strongly suggests that in such areas, effective infection control is required prior to iron supplementation to avoid increasing preterm births. Trial registration NCT01210040. Registered with Clinicaltrials.gov on 27th September 2010.
Assuntos
Gastroenteropatias/etiologia , Ferro/administração & dosagem , Malária/parasitologia , Nascimento Prematuro/epidemiologia , Adolescente , Burkina Faso , Suplementos Nutricionais/análise , Feminino , Humanos , Modelos Teóricos , Nascimento Prematuro/etiologia , Risco , Adulto JovemRESUMO
BACKGROUND: Iron supplementation before a first pregnancy may improve the future health of mother and baby by reducing maternal anaemia. Iron supplementation could, however, increase malaria infections, notably in primigravidae who are most susceptible. The pathogenicity of other iron-utilizing pathogens could also increase, causing inflammation leading to increased risk of adverse birth outcomes. This paper reports pre-specified secondary birth outcomes from a safety trial in Burkina Faso in an area of high malaria endemicity. Primary outcomes from that trial had investigated effects of long-term weekly iron supplementation on malaria and genital tract infections in non-pregnant and pregnant women. METHODS: A double-blind, randomized controlled trial. Nulliparous, mainly adolescent women, were individually randomized periconceptionally to receive weekly either 60 mg elemental iron and 2.8 mg folic acid, or 2.8 mg folic acid alone, continuing up to the first antenatal visit for those becoming pregnant. Secondary outcomes were ultrasound-dated gestational age, fetal growth, placental malaria, chorioamnionitis and iron biomarkers. Seasonal effects were assessed. Analysis was by intention to treat. RESULTS: 478 pregnancies occurred to 1959 women: 258/980 women assigned iron and folic acid and 220/979 women assigned folic acid alone. Malaria prevalence at the first antenatal visit was 53% (iron) and 55% (controls). Mean birthweight was 111 g lower in the iron group (95% CI 9:213 g, P = 0.033). Mean gestational ages were 264 days (iron) and 269 days (controls) (P = 0.012), with 27.5% under 37 weeks compared to 13.9% in controls (adjRR = 2.22; 95% CI 1.39-3.61) P < 0.001). One-third of babies were growth restricted, but incidence did not differ by trial arm. Half of placentae had evidence of past malaria infection. C-reactive protein > 5 mg/l was more common prior to births < 37 weeks (adjRR = 2.06, 95% CI 1.04-4.10, P = 0.034). Preterm birth incidence during the rainy season was ~ 50% in the iron arm and < 20% in controls (P = 0.001). Chorioamnionitis prevalence peaked in the dry season (P = 0.046), with no difference by trial arm (P = 0.14). CONCLUSION: Long-term weekly iron supplementation given to nulliparous women in a malaria endemic area was associated with higher risk of preterm birth in their first pregnancy. Trial Registration NCT01210040. Registered with Clinicaltrials.gov on 27th September 2010.
Assuntos
Suplementos Nutricionais/efeitos adversos , Ferro/administração & dosagem , Malária/epidemiologia , Fenômenos Fisiológicos da Nutrição Materna , Nascimento Prematuro/etiologia , Adolescente , Peso ao Nascer/efeitos dos fármacos , Burkina Faso/epidemiologia , Método Duplo-Cego , Doenças Endêmicas , Feminino , Ácido Fólico/administração & dosagem , Idade Gestacional , Humanos , Recém-Nascido , Ferro/efeitos adversos , Malária/complicações , Micronutrientes/administração & dosagem , Micronutrientes/efeitos adversos , Gravidez , Nascimento Prematuro/epidemiologia , Prevalência , Fatores de Risco , Adulto JovemRESUMO
Background: The safety of iron supplementation for young women is uncertain in malaria-endemic settings. Methods: This was a double-blind, randomized controlled noninferiority trial in rural Burkina Faso. Results: A total of 1959 nulliparae were assigned to weekly supplementation (60 mg iron and 2.8 mg folic acid) (n = 980) or 2.8 mg folic acid (n = 979) until first antenatal visit (ANC1), or 18 months if remaining nonpregnant. Three hundred fifteen women attended ANC1, and 916 remained nonpregnant. There was no difference at ANC1 in parasitemia prevalence (iron, 53.4% [95% confidence interval {CI}, 45.7%-61.0%]; control, 55.3% [95% CI, 47.3%-62.9%]; prevalence ratio, 0.97 [95% CI, .79-1.18]; P = .82), anemia (adjusted effect, 0.96 [95% CI, .83-1.10]; P = .52), iron deficiency (adjusted risk ratio [aRR], 0.84 [95% CI, .46-1.54]; P = .58), or plasma iron biomarkers. Outcomes in nonpregnant women were parasitemia (iron, 42.9% [95% CI, 38.3%-47.5%]; control, 39.2% [95% CI, 34.9%-43.7%]; prevalence ratio, 1.09 [95% CI, .93-1.28]; P = .282); anemia (aRR, 0.90 [95% CI, .78-1.05]; P = .17), and iron deficiency (aRR, 0.99 [95% CI, .77-1.28]; P = .96), with no iron biomarker differences. Conclusions: Weekly iron supplementation did not increase malaria risk, improve iron status, or reduce anemia in young, mostly adolescent menstruating women, nor in early pregnancy. World Health Organization Guidelines for universal supplementation for young nulliparous women may need reassessment. Clinical Trials Registration: NCT01210040.
Assuntos
Anemia/prevenção & controle , Suplementos Nutricionais , Ácido Fólico/administração & dosagem , Ferro/administração & dosagem , Malária/prevenção & controle , Adolescente , Feminino , Humanos , Ferro/sangue , Gravidez , Organização Mundial da SaúdeRESUMO
BACKGROUND: Iron deficiency remains a prevalent adolescent health problem in low income countries. Iron supplementation is recommended but improvement of iron status requires good adherence. OBJECTIVES: We explored factors affecting adolescent adherence to weekly iron and/or folic acid supplements in a setting of low secondary school attendance. METHODS: Taped in-depth interviews were conducted with participants in a randomised, controlled, periconceptional iron supplementation trial for young nulliparous women living in a rural, malaria endemic region of Burkina Faso. Participants with good, medium or poor adherence were selected. Interviews were transcribed and analysed thematically. RESULTS: Thirty-nine interviews were conducted. The community initially thought supplements were contraceptives. The potential benefits of giving iron supplementation to unmarried "girls" ahead of pregnancy were not recognised. Trial participation, which required parental consent, remained high but was not openly admitted because iron supplements were thought to be contraceptives. Unmarried non-school attenders, being mobile, were often sent to provide domestic labour in varied locations. This interrupted adherence - as did movement of school girls during vacations and at marriage. Field workers tracked participants and trial provision of free treatment encouraged adherence. Most interviewees did not identify health benefits from taking supplements. CONCLUSIONS: For success, communities must be convinced of the value of an adolescent intervention. During this safety trial, benefits not routinely available in iron supplementation programmes were important to this low income community, ensuring adolescent participation. Nevertheless, adolescents were obliged to fulfil cultural duties and roles that interfered with regular adherence to the iron supplementation regime. TRIAL REGISTRATION: Trial Registration at clinicaltrials.gov : NCT01210040.
Assuntos
Fenômenos Fisiológicos da Nutrição do Adolescente , Suplementos Nutricionais , Ácido Fólico/administração & dosagem , Ferro da Dieta/administração & dosagem , Cooperação do Paciente , Cuidado Pré-Concepcional , Saúde da População Rural , Adolescente , Fenômenos Fisiológicos da Nutrição do Adolescente/etnologia , Anemia Ferropriva/epidemiologia , Anemia Ferropriva/etnologia , Anemia Ferropriva/prevenção & controle , Burkina Faso/epidemiologia , Estudos de Coortes , Assistência à Saúde Culturalmente Competente/etnologia , Países em Desenvolvimento , Feminino , Grupos Focais , Ácido Fólico/uso terapêutico , Seguimentos , Humanos , Ferro da Dieta/uso terapêutico , Defeitos do Tubo Neural/epidemiologia , Defeitos do Tubo Neural/etnologia , Defeitos do Tubo Neural/prevenção & controle , Cooperação do Paciente/etnologia , Prevalência , Sistemas de Apoio Psicossocial , Pesquisa Qualitativa , Características de Residência , Saúde da População Rural/etnologiaRESUMO
BACKGROUND: Provision of routine iron supplements to prevent anaemia could increase the risk for lower genital tract infections as virulence of some pathogens depends on iron availability. This trial in Burkina Faso assessed whether weekly periconceptional iron supplementation increased the risk of lower genital tract infection in young non-pregnant and pregnant women. METHODS: Genital tract infections were assessed within a double blind, controlled, non-inferiority trial of malaria risk among nulliparous women, randomised to receive either iron and folic acid or folic acid alone, weekly, under direct observation for 18 months. Women conceiving during this period entered the pregnancy cohort. End assessment (FIN) for women remaining non-pregnant was at 18 months. For the pregnancy cohort, end assessment was at the first scheduled antenatal visit (ANC1). Infection markers included Nugent scores for abnormal flora and bacterial vaginosis (BV), T. vaginalis PCR, vaginal microbiota, reported signs and symptoms, and antibiotic and anti-fungal prescriptions. Iron biomarkers were assessed at baseline, FIN and ANC1. Analysis compared outcomes by intention to treat and in iron replete/deficient categories. RESULTS: A total of 1954 women (mean 16.8 years) were followed and 478 (24.5%) became pregnant. Median supplement adherence was 79% (IQR 59-90%). Baseline BV prevalence was 12.3%. At FIN and ANC1 prevalence was 12.8% and 7.0%, respectively (P < 0.011). T. vaginalis prevalence was 4.9% at FIN and 12.9% at ANC1 (P < 0.001). BV and T. vaginalis prevalence and microbiota profiles did not differ at trial end-points. Iron-supplemented non-pregnant women received more antibiotic treatments for non-genital infections (P = 0.014; mainly gastrointestinal infections (P = 0.005), anti-fungal treatments for genital infections (P = 0.014) and analgesics (P = 0.008). Weekly iron did not significantly reduce iron deficiency prevalence. At baseline, iron-deficient women were more likely to have normal vaginal flora (P = 0.016). CONCLUSIONS: Periconceptional weekly iron supplementation of young women did not increase the risk of lower genital tract infections but did increase general morbidity in the non-pregnant cohort. Unabsorbed gut iron due to malaria could induce enteric infections, accounting for the increased administration of antibiotics and antifungals in the iron-supplemented arm. This finding reinforces concerns about routine iron supplementation in highly malarious areas. TRIAL REGISTRATION: Trial registration number NCT01210040 . Registered with Clinicaltrials.gov on 27 September 2010.
Assuntos
Ácido Fólico/farmacologia , Ferro/farmacologia , Infecções do Sistema Genital/induzido quimicamente , Adolescente , Anemia/prevenção & controle , Burkina Faso , Suplementos Nutricionais , Método Duplo-Cego , Feminino , Ácido Fólico/administração & dosagem , Seguimentos , Humanos , Malária/diagnóstico , Gravidez , Cuidado Pré-Natal , Prevalência , Vagina/microbiologiaRESUMO
Periconceptional supplementation could extend the period over which maternal and fetal nutrition is improved, but there are many challenges facing early-life intervention studies. Periconceptional trials differ from pregnancy supplementation trials, not only because of the very early or pre-gestational timing of nutrient exposure but also because they generate subsidiary information on participants who remain non-pregnant. The methodological challenges are more complex although, if well designed, they provide opportunities to evaluate concurrent hypotheses related to the health of non-pregnant women, especially nulliparous adolescents. This review examines the framework of published and ongoing randomised trial designs. Four cohorts typically arise from the periconceptional trial design--two of which are non-pregnant and two are pregnant--and this structure provides assessment options related to pre-pregnant, maternal, pregnancy and fetal outcomes. Conceptually the initial decision for single or micronutrient intervention is central--as is the choice of dosage and content--in order to establish a comparative framework across trials, improve standardisation, and facilitate interpretation of mechanistic hypotheses. Other trial features considered in the review include: measurement options for baseline and outcome assessments; adherence to long-term supplementation; sample size considerations in relation to duration of nutrient supplementation; cohort size for non-pregnant and pregnant cohorts as the latter is influenced by parity selection; integrating qualitative studies and data management issues. Emphasis is given to low resource settings where high infection rates and the possibility of nutrient-infection interactions may require appropriate safety monitoring. The focus is on pragmatic issues that may help investigators planning a periconceptional trial.
Assuntos
Suplementos Nutricionais , Cuidado Pré-Natal , Projetos de Pesquisa , Feminino , Humanos , Lactente , Recém-Nascido , Micronutrientes/administração & dosagem , Avaliação de Resultados em Cuidados de Saúde , Gravidez , Ensaios Clínicos Controlados Aleatórios como AssuntoRESUMO
BACKGROUND: Maternal micronutrient deficiencies are commonly associated with clinical indicators of placental dysfunction. OBJECTIVE: We tested the hypothesis that periconceptional multiple-micronutrient supplementation (MMS) affects placental function. DESIGN: We conducted a double-blind, randomized, placebo-controlled trial of MMS in 17- to 45-y-old Gambian women who were menstruating regularly and within the previous 3 mo. Eligible subjects were pre-randomly assigned to supplementation with the UNICEF/WHO/United Nations University multiple micronutrient preparation (UNIMMAP) or placebo on recruitment and until they reached their first antenatal check-up or for 1 y if they failed to conceive. Primary outcome measures were midgestational indexes of utero-placental vascular-endothelial function [ratio of plasminogen-activator inhibitor (PAI) 1 to PAI-2 and mean uterine-artery resistance index (UtARI)] and placental active transport capacity at delivery [fetal to maternal measles antibody (MMA) ratio]. RESULTS: We recruited 1156 women who yielded 415 pregnancies, of which 376 met all of the inclusion criteria. With adjustment for gestational age at sampling, there were no differences in PAI-1 to PAI-2 or MMA ratios between trial arms, but there was a 0.02-unit reduction in UtARI between 18 and 32 wk of gestation (95% CI: -0.03, -0.00; P = 0.040) in women taking UNIMMAP. CONCLUSIONS: Placental vascular function was modifiable by periconceptional micronutrient supplementation. However, the effect was small and supplementation did not further affect other variables of placental function. This trial was registered at www.controlled-trials.com as ISRCTN 13687662.
Assuntos
Deficiências Nutricionais/prevenção & controle , Suplementos Nutricionais , Fenômenos Fisiológicos da Nutrição Materna , Micronutrientes/uso terapêutico , Placentação , Cuidado Pré-Concepcional , Saúde da População Rural , Adolescente , Adulto , Biomarcadores/sangue , Estudos de Coortes , Deficiências Nutricionais/sangue , Deficiências Nutricionais/fisiopatologia , Suplementos Nutricionais/efeitos adversos , Método Duplo-Cego , Feminino , Seguimentos , Gâmbia , Humanos , Micronutrientes/efeitos adversos , Circulação Placentária , Gravidez , Complicações na Gravidez/sangue , Complicações na Gravidez/fisiopatologia , Complicações na Gravidez/prevenção & controle , Nações Unidas , Resistência Vascular , Adulto JovemRESUMO
OBJECTIVE: To evaluate the quality of policies concerning the diagnosis, treatment and prevention of anaemia in children and adolescents; to determine to what extent these are evidence-based; and to use this analysis to inform the policy-making process. SUBJECTS: Children and adolescents in sub-Saharan Africa. SETTING: Almost 50 % of children and adolescents in sub-Saharan Africa are anaemic, which has profound effects on their intellectual and physical development and their chance of survival. Evidence-based policies are essential to reduce anaemia but because it is caused by an array of interdependent factors, developing policies is challenging. DESIGN: Forty-six policy documents concerning the diagnosis, treatment and prevention of anaemia in children and adolescents were identified and analysed. RESULTS: There was policy consensus on the usefulness of Fe supplements, the need to treat co-morbidities and the use of blood transfusions for severe anaemia. Information about diagnosis was scarce, and messages regarding the control of anaemia were mixed. Few of the policies were tailored for the African context and they were located on several websites hosted by different health programmes. CONCLUSIONS: The weakest aspects of the policies and consequently the priorities for better policy making were: lack of adherence to WHO recommendations for guideline development; little involvement of African practitioners/policy makers in the guideline group and as peer reviewers; and lack of harmonisation, demonstrating the need to establish a single body responsible for developing/revising anaemia policies.
Assuntos
Anemia/tratamento farmacológico , Anemia/prevenção & controle , Política Pública , Adolescente , África Subsaariana , Anemia/diagnóstico , Criança , Países em Desenvolvimento , Suplementos Nutricionais , Prática Clínica Baseada em Evidências , Humanos , Ferro da Dieta/administração & dosagem , Formulação de Políticas , Organização Mundial da SaúdeRESUMO
Infection is a major cause of neonatal death in developing countries. This review investigates whether host iron status affects the risk of maternal and/or neonatal infection, potentially contributing to neonatal death, and summarizes the iron acquisition mechanisms described for pathogens causing stillbirth, preterm birth, and congenital infection. In vitro evidence shows that iron availability influences the severity and chronicity of infections that cause these negative outcomes of pregnancy. In vivo evidence is lacking, as relevant studies of maternal iron supplementation have not assessed the effect of iron status on the risk of maternal and/or neonatal infection. Reducing iron-deficiency anemia among women is beneficial and should improve the iron stores of babies; moreover, there is evidence that iron status in young children predicts the risk of malaria and, possibly, the risk of invasive bacterial diseases. Caution with maternal iron supplementation is indicated in iron-replete women who may be at high risk of exposure to infection, although distinguishing between iron-replete and iron-deficient women is currently difficult in developing countries, where a point-of-care test is needed. Further research is indicated to investigate the risk of infection relative to iron status in mothers and babies in order to avoid iron intervention strategies that may result in detrimental birth outcomes in some groups of women.
Assuntos
Nível de Saúde , Mortalidade Infantil , Infecções/epidemiologia , Ferro/sangue , Complicações Infecciosas na Gravidez/epidemiologia , Anemia Ferropriva/epidemiologia , Anemia Ferropriva/prevenção & controle , Países em Desenvolvimento/estatística & dados numéricos , Feminino , Humanos , Recém-Nascido , Gravidez , Complicações Infecciosas na Gravidez/prevenção & controle , Resultado da Gravidez , Nascimento Prematuro , Fatores de RiscoRESUMO
OBJECTIVES: To identify by type and sensitivity to drugs the bacteria found in ears of school-going children with chronic otitis media in Garissa district. STUDY DESIGN: This was a descriptive prevalence study of CSOM bacterial flora in eligible ears conducted among a cohort of children attending public and private primary as well as Islamic religious schools, screened for chronic ear discharge in Garissa district, Kenya. Procedure and bacteriological techniques: We used sterile swab-sticks to collect a specimen of the discharge from eligible ears of consenting pupils at the induction stage of the zinc supplementation trial for treatment of chronic suppurative otitis media conducted between January and July 2010. All pupils below 18 years present on day of visit were eligible. Both aerobic and anaerobic bacterial cultures were done to identify clinically and epidemiologically important bacteria. Sensitivity tests were based on disc diffusion methods. Results are presented as frequencies and proportions. RESULTS: Of the pupils seen, 61% were still in pre- or lower primary school. Majority were aged 13 and 14 years. Of the 261 ear swab samples processed, 336 isolates - either in mixed or pure flora - were identified, being almost exclusively aerobes. Proteus spp., Enterococcus, Staphylococcus aureus and Pseudomonas spp. were isolated in 32.7%, 28.6%, 12.8% and 11.3% respectively. Proteus was susceptible to majority of the antibiotics tested for, while Enterococcus was poorly susceptible. CONCLUSIONS: Aerobic bacteria were most prevalent in this study. Several of the bacteria identified are known to require iron for their growth. This may be important for CSOM treatment if biofilm formation is involved in pathogenesis. Majority of the isolates were susceptible to basic antibiotics compared to Enterococcus bacteria. This portends an important consideration for clinical management and therapeutic decision-making. Additionally, given the prevalence of Enterococcus bacteria, which is an indicator of faecal contamination of the environment, there is need to consider relevant public health components in managing childhood CSOM besides the clinical ones alone.
Assuntos
Anti-Infecciosos/uso terapêutico , Orelha Média/microbiologia , Otite Média Supurativa/microbiologia , Adolescente , Criança , Pré-Escolar , Doença Crônica , Feminino , Humanos , Quênia/epidemiologia , Masculino , Testes de Sensibilidade Microbiana , Otite Média Supurativa/tratamento farmacológico , Otite Média Supurativa/epidemiologia , PrevalênciaRESUMO
INTRODUCTION: Iron deficiency is highly prevalent in pre-school children in developing countries and an important health problem in sub-Saharan Africa. A debate exists on the possible protective effect of iron deficiency against malaria and other infections; yet consensus is lacking due to limited data. Recent studies have focused on the risks of iron supplementation but the effect of an individual's iron status on malaria risk remains unclear. Studies of iron status in areas with a high burden of infections often are exposed to bias. The aim of this study was to assess the predictive value of baseline iron status for malaria risk explicitly taking potential biases into account. METHODS AND MATERIALS: We prospectively assessed the relationship between baseline iron deficiency (serum ferritin <30 µg/L) and malaria risk in a cohort of 727 Malawian preschool children during a year of follow-up. Data were analyzed using marginal structural Cox regression models and confounders were selected using causal graph theory. Sensitivity of results to bias resulting from misclassification of iron status by concurrent inflammation and to bias from unmeasured confounding were assessed using modern causal inference methods. RESULTS AND CONCLUSIONS: The overall incidence of malaria parasitemia and clinical malaria was 1.9 (95% CI 1.8-2.0) and 0.7 (95% CI 0.6-0.8) events per person-year, respectively. Children with iron deficiency at baseline had a lower incidence of malaria parasitemia and clinical malaria during a year of follow-up; adjusted hazard ratio's 0.55 (95%-CI:0.41-0.74) and 0.49 (95%-CI:0.33-0.73), respectively. Our results suggest that iron deficiency protects against malaria parasitemia and clinical malaria in young children. Therefore the clinical importance of treating iron deficiency in a pre-school child should be weighed carefully against potential harms. In malaria endemic areas treatment of iron deficiency in children requires sustained prevention of malaria.
Assuntos
Ferro/sangue , Malária/epidemiologia , Pré-Escolar , Fatores de Confusão Epidemiológicos , Feminino , Humanos , Incidência , Lactente , Malária/sangue , Malaui/epidemiologia , Masculino , Estudos ProspectivosRESUMO
Patients with Sickle cell disease (SCD) exhibit signs of poor growth, increased susceptibility to infection and recurrent episodes of painful vaso-occlusive crises. Micronutrient deficiencies may increase susceptibility to these outcomes. We conducted a systematic review to assess the strength of evidence for improved outcomes related to micronutrient interventions. Six randomized-controlled trials of moderate quality met the inclusion criteria. Zinc supplementation was associated with improved growth and decreased incidence of infection and is a promising intervention in the management of SCD patients. Omega-3 fatty acid supplementation was associated with limited reduction in vaso occlusive crises. This review identifies key knowledge gaps, which are important research priorities for nutritional interventions.
Assuntos
Anemia Falciforme/complicações , Anemia Falciforme/patologia , Arteriopatias Oclusivas/etiologia , Infecções/etiologia , Micronutrientes/deficiência , HumanosRESUMO
In 2006, the World Health Organization and the United Nations Children's Fund released a joint statement advising that, in regions where the prevalence of malaria and other infectious diseases is high, iron and folic acid supplementation should be limited to those who are identified as iron-deficient. Although precipitated, in large part, by a recent report of adverse events associated with iron supplementation in children, questions about the risk/benefit of iron deficiency and mechanisms underlying potential adverse effects of iron in the context of infection are long-standing. Moreover, the implementation of this revised policy is compromised in most settings by the lack of consensus on the best methods to screen for iron deficiency. In response to these concerns a comprehensive review was conducted by a Technical Working Group (TWG), constituted by the Eunice Kennedy Shriver National Institute of Child Health and Human Development of the U.S. National Institutes of Health, in partnership with the Bill and Melinda Gates Foundation. The review included an evaluation of the putative mechanisms associated with adverse effects of iron in the context of malaria; applicability of available biomarkers for assessing iron status in the context of infections; and evaluation of evidence with regard to the safety and effectiveness of available interventions to prevent iron deficiency, particularly in areas of endemic malaria. The aim of this paper is to summarize the technical details of the larger TWG review conclusion that the occurrence and mechanism(s) of adverse effects associated with providing iron supplements (i. e., pills/liquid) under conditions of malaria and high infection exposure remain a concern, especially in settings where care and treatment are not readily available or accessible. Iron deficiency remains a problem that demands appropriate clinical care. When target groups have already been identified as being iron-deficient, iron supplementation is the intervention of choice for the treatment of anemia and other manifestations of iron deficiency. Of available intervention options to prevent iron deficiency, supplements are probably least desirable, particularly for infants and children. This paper also provides a synopsis of the TWG responses to the recently published Cochrane Review on the safety of iron supplementation for children in the context of malaria, and a research agenda outlined by the TWG that can best address outstanding questions.
Assuntos
Suplementos Nutricionais/efeitos adversos , Doenças Endêmicas , Saúde Global , Ferro da Dieta/efeitos adversos , Malária/epidemiologia , Adolescente , Adulto , Anemia Ferropriva/diagnóstico , Anemia Ferropriva/dietoterapia , Anemia Ferropriva/prevenção & controle , Biomarcadores/sangue , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Ferro da Dieta/uso terapêutico , Malária/sangue , Masculino , Fenômenos Fisiológicos da Nutrição Materna , National Institute of Child Health and Human Development (U.S.) , Gravidez , Estados Unidos , Adulto JovemRESUMO
The ability to develop evidence-based clinical guidance and effective programs and policies to achieve global health promotion and disease prevention goals depends on the availability of valid and reliable data. With specific regard to the role of food and nutrition in achieving those goals, relevant data are developed with the use of biomarkers that reflect nutrient exposure, status, and functional effect. A need exists to promote the discovery, development, and use of biomarkers across a range of applications. In addition, a process is needed to harmonize the global health community's decision making about what biomarkers are best suited for a given use under specific conditions and settings. To address these needs, the Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, US Department of Health and Human Services, organized a conference entitled "Biomarkers of Nutrition for Development: Building a Consensus," which was hosted by the International Atomic Energy Agency. Partners included key multilateral, US agencies and public and private organizations. The assembly endorsed the utility of this initiative and the need for the BOND (Biomarkers of Nutrition for Development) project to continue. A consensus was reached on the requirement to develop a process to inform the community about the relative strengths or weaknesses and specific applications of various biomarkers under defined conditions. The articles in this supplement summarize the deliberations of the 4 working groups: research, clinical, policy, and programmatic. Also described are content presentations on the harmonization processes, the evidence base for biomarkers for 5 case-study micronutrients, and new frontiers in science and technology.
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Biomarcadores/análise , Desenvolvimento Infantil , Consenso , Estado Nutricional , Criança , HumanosRESUMO
BACKGROUND: Nutritional iron deficiency may limit iron availability to the malaria parasite reducing infection risk, and/or impair host immunity thereby increasing this risk. In pregnant women, there is evidence of an adverse effect with iron supplementation, but the few reported studies are strongly confounded. METHODS: A case control study in pregnant Malawian women was undertaken in Chikhwawa southern Malawi in order to describe iron status in relation to placental malaria controlling for several confounding factors. Pregnancy characteristics were obtained and a blood sample at delivery. A full blood count was performed and serum ferritin and transferrin receptor quantified by enzyme-linked immunoassay. DNA analysis was used to identify genetic polymorphisms for ABO phenotype, hemoglobin HbS, and glucose -6 phosphate dehydrogenase deficiency. Placental tissue was obtained and malaria histology classified as active, past or no malaria infection. RESULTS: 112 cases with placental malaria were identified and 110 women with no evidence of placental infection. Iron deficiency was less frequent in women with placental Plasmodium falciparum infection. In those with acute, chronic or past placental infections the odds ratio for iron deficiency was 0.4, 95% CI 0.2-0.8, p = 0.01; for acute and chronic infections 0.4, 0.2-0.8, p = 0.006; for acute infection 0.3, 0.1-0.7, p = 0.001. The association was greater in multigravidae. CONCLUSION: Women with either acute, or acute and chronic placental malaria were less likely to have iron deficiency than women without placental malaria infection There is a priority to establish if reversing iron deficiency through iron supplementation programs either prior to or during pregnancy enhances malaria risk.
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Deficiências de Ferro , Malária Falciparum/epidemiologia , Complicações Infecciosas na Gravidez/epidemiologia , Sistema ABO de Grupos Sanguíneos/genética , Contagem de Células Sanguíneas , Estudos de Casos e Controles , Ensaio de Imunoadsorção Enzimática , Feminino , Ferritinas/sangue , Glucosefosfato Desidrogenase/genética , Hemoglobina Falciforme/genética , Humanos , Malaui/epidemiologia , Polimorfismo Genético , Gravidez , Receptores da Transferrina/sangue , Medição de RiscoRESUMO
OBJECTIVE: To describe pregnancy outcomes of adolescent and adult primigravidae receiving antimalarials and hematinic supplementation and compare findings with a survey in this area a decade earlier. DESIGN: Cross-sectional surveys in intervention and control sites. SETTING: Community, antenatal and delivery facilities in Chikwawa, Malawi. A rural area with year round malaria transmission. METHODS: Data on antenatal attendance, uptake of intermittent preventive treatment with sulfadoxine-pyrimethamine (IPTp-SP), birthweight, malaria, anaemia, for 2,152 primigravidae. OUTCOME MEASURES: Place of delivery, anaemia, malaria, birthweight. RESULTS: Fewer adolescent than adult primigravidae received >or=2 IPTp-SP doses (66 vs. 77.2%, p < 0.001), although more attended for two or more antenatal visits (92.0 vs. 76.7%, p < 0.001). Only 24.1% of adolescent primigravidae attended for hospital delivery. Women resident in intervention sites receiving IPTp-SP community distribution were more likely to choose a community delivery (p < 0.01), and have higher uptake of IPTp-SP (p = 0.036) than women not resident in these villages. Postnatal malaria prevalence was low and did not differ by age or place of delivery. Postnatal anaemia and low birthweight prevalence were higher in adolescents with community deliveries. Maternal anaemia and low birthweight prevalence were lower amongst adolescents in this study compared to estimates from the same population a decade previously. CONCLUSIONS: Adolescents had higher anaemia risk, lower IPTp-SP uptake than adults and under a quarter had a hospital delivery. Pregnancy outcomes improved compared to the survey a decade earlier. Monitoring and surveillance is required to reinforce to policy makers the need to improve adolescent coverage for available interventions.