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Biomedical subjects

Rebecca J Stoltzfus

Publications and source records attributed to Rebecca J Stoltzfus.

11 recordsLinked to original sources
PubMed2004

Low dose daily iron supplementation improves iron status and appetite but not anemia, whereas quarterly anthelminthic treatment improves growth, appetite and anemia in Zanzibari preschool children.

Iron deficiency and helminth infections are two common conditions of children in developing countries. The consequences of helminth infection in young children are not well described, and the efficacy of low dose iron supplementation is not well documented in malaria-endemic settings. A 12-mo randomized, placebo controlled, double-blind trial of 10 mg daily iron and/or mebendazole (500 mg) every 3 mo was conducted in a community-based sample of 459 Zanzibari children age 6-71 mo with hemoglobin > 70 g/L at baseline. The trial was designed to examine treatment effects on growth, anemia and appetite in two age subgroups. Iron did not affect growth retardation, hemoglobin concentration or mild or moderate anemia (hemoglobin < 110 g/L or < 90 g/L, respectively), but iron significantly improved serum ferritin and erythrocyte protoporphyrin. Mebendazole significantly reduced wasting malnutrition. but only in children <30 mo old. The adjusted odds ratios (AORs) for mebendazole in this age group were 0.38 (95% CI: 0.16, 0.90) for weight-for-height less than -1 Z-score and 0.29 (0.09, 0.91) for small arm circumference. In children <24 mo old, mebendazole also reduced moderate anemia (AOR: 0.41, 0.18, 0.94). Both iron and mebendazole improved children's appetite, according to mothers' report. In this study, iron's effect on anemia was limited, likely constrained by infection, inflammation and perhaps other nutrient deficiencies. Mebendazole treatment caused unexpected and significant reductions in wasting malnutrition and anemia in very young children with light infections. We hypothesize that incident helminth infections may stimulate inflammatory immune responses in young children, with deleterious effects on protein metabolism and erythropoiesis.

Anemia, Iron-Deficiency↗
PubMed2004

Blood lead, anemia, and short stature are independently associated with cognitive performance in Mexican school children.

Lead exposure and nutritional factors are both associated with cognitive performance. Lead toxicity and nutritional status are also associated with each other. We examined whether nutritional status variables account for part or all of the association between cognitive performance and lead exposure. First-grade children (n = 724) ages 6-8 y, attending Mexican public schools located in the vicinity of a metal foundry were asked to participate and 602 enrolled in the study. Blood lead, iron status, anemia, anthropometry, and cognitive function were assessed. Results from 7 standardized tests are presented here. The mean blood lead concentration was 11.5 +/- 6.1 micro g/dL (0.56 +/- 0.30 micro mol/L) and 50% of the children had concentrations >10 micro g/dL (0.48 micro mol/L). The prevalence of mild anemia (<124 g/L) was low (10%) and stunting (<2 SD) was nonexistent (2.3%). In bivariate analyses, lead was negatively associated with 4 cognitive tests and was also inversely correlated with iron status, height-for-age Z scores, and head circumference. In multivariate models, the association between lead and cognitive performance was not strongly affected by nutritional variables, suggesting that the relation of lead to cognition is not explained by lead's relation to iron deficiency anemia or growth retardation. In multivariate models, hemoglobin concentration was also positively associated with Peabody Picture Vocabulary Test and Number Sequencing performance, whereas serum ferritin was negatively related to the Coding subscale of the Wechsler Intelligence Scales for Children-Revised Mexican Version (WISC-RM).

Anemia↗
PubMed2004

New evidence of iron and zinc interplay at the enterocyte and neural tissues.

Because combined iron-zinc supplementation regimens are employed with increasing frequency in field trials to combat co-occurring iron and zinc deficiencies, there is a growing concern for potential antagonisms between these 2 metals. Several supplementation trials hinted at such a competition, and the intestinal divalent metal transporter-1 (DMT1) has often been cited as a possible site for its occurrence. We summarize new evidence showing that although iron does seem to reduce the absorption of zinc, the DMT1 is an unlikely site for this absorptive antagonism by virtue of the fact that zinc is not transported by the DMT1. We also propose a shift in thinking about iron-zinc interactions from the level of enterocyte to other sites/systems in the body that may be equally relevant for the outcome and interpretation of supplementation trials. We present an overview of iron and zinc absorption and function in neural tissue as one example of possible interactions.

Animals↗
PubMed2003

Performance of the Haemoglobin Colour Scale in diagnosing severe and very severe anaemia.

OBJECTIVE: To assess the accuracy of Haemoglobin Colour Scale (HCS) in identifying severely anaemic [haemoglobin (Hb) <7 g/dl] and very severely anaemic (Hb <5 g/dl) individuals, and to compare the performances of a group of health workers using HCS after training with a standard method. METHOD: The study consisted of two parts. In part 1, the performance of HCS was compared with clinical examination in a hospital population of which more than 450 individuals were severely anaemic and more than 120 very severely anaemic. Part 2 of the study was conducted in eight dispensaries where the performances of 13 health workers using the colour scale were compared with the performances of eight other health workers using clinical signs to estimate Hb. RESULTS: The colour scale was 92% sensitive for both severe anaemia and very severe anaemia and performed better than clinical examination. Health workers who used the colour scale did better in identifying anaemic and severely anaemic individuals, than those who used clinical examination. CONCLUSIONS: The colour scale improves health workers' capacity to identify severely anaemic individuals and could be used as a basis for referral. Although the diagnostic accuracy of the workers using HCS varied widely, in most cases they did significantly better than those who used clinical investigation alone.

Adult↗
PubMed2003

Total body iron in HIV-positive and HIV-negative Zimbabwean newborns strongly predicts anemia throughout infancy and is predicted by maternal hemoglobin concentration.

One method of preventing postnatal iron deficiency is to ensure that the infant is born with a full endowment of iron. We calculated total body iron at birth (TBI) as the sum of hemoglobin iron (HbI) and body storage iron (BSI) in 2021 Zimbabwean newborns, and related TBI to subsequent anemia from 3 to 12 mo of age and to maternal and fetal characteristics. We estimated the mean +/- SD TBI to be 210 +/- 41 mg. There was an inverse dose-response association between TBI quartile and risk of anemia at all postnatal ages. The odds of anemia were >3 times higher in the lowest vs. highest TBI quartile (P < 0.001) at 6, 9 and 12 mo. Preterm birth and parity were not independently associated with TBI after controlling for birthweight. The predicted change in TBI per kilogram increase in birthweight was 68 mg (P < 0.001). After adjusting for birthweight, TBI increased by 25 mg with each 10-y decrement in maternal age (P = 0.033). Maternal hemoglobin was a strong linear predictor of TBI (P < 0.001). Maternal and infant HIV infection, especially among girls, was associated with apparently greater estimated TBI. We speculate that this is actually an artifact, explained by an inflammatory response, and that there was a sex difference in the response. We conclude that we can make satisfactory estimates of TBI and that the assumptions required for this approach are sufficiently robust to lead to an acceptable estimate of the prenatally acquired iron endowment. Babies born with low birthweight or to mothers with low hemoglobin are born with less TBI, which confers a substantially greater risk of anemia from 3 to 12 mo of age.

Anemia↗
PubMed2003

Iron and ascorbic Acid: proposed fortification levels and recommended iron compounds.

An adequate supply of dietary iron during the 1st 24 mo of life is essential for preventing iron deficiency with its attendant negative effects on mental, motor and emotional development as well as later cognitive performance. Iron reserves and the small amount of highly bioavailable iron in human milk are adequate to satisfy the iron requirements of breast-fed infants of adequate birth weight for the 1st 6 mo of life. Thereafter, complementary foods, iron supplements or both are needed to meet this requirement. Complementary foods should not displace the consumption of human milk. The quantities eaten, particularly by younger infants, may therefore be quite small. As a consequence it is essential that the iron be supplied in a highly bioavailable form. This can be achieved by fortifying complementary foods with ferrous sulfate and ascorbic acid provided that the ascorbic acid is not lost during storage or meal preparation. Suggested fortification levels for ferrous sulfate and ascorbic acid for some types of complementary foods are given. The use of ferrous fumarate or an elemental iron powder instead of ferrous sulfate has not been evaluated adequately. There is a need to develop alternative strategies for improving iron bioavailability in complementary foods because it may not be possible to preserve ascorbic acid activity in many of them.

Ascorbic Acid↗
PubMed2002

Breastmilk erythropoietin and mother-to-child HIV transmission through breastmilk.

A third to a half the 1.5 million HIV-positive children in the world today acquired their infection via breastfeeding. However, what protects the 85% of breastfed babies of HIV-infected mothers who do not become infected? We postulate that erythropoietin (EPO), a hormone in human milk, has a role in the prevention of HIV transmission during breastfeeding. EPO might maintain mammary epithelium integrity, thereby reducing viral loads in milk, or maintain intestinal epithelial integrity in the breastfed neonate, and thus preventing ingested milk-borne virus being infective. This hypothesis could be tested by administration of recombinant human EPO parenterally to HIV-infected mothers or enterally to breastfed babies, or both, and assessment of the effect on mammary permeability, viral load in milk, and intestinal permeability in babies. If our hypothesis is correct, EPO treatment for mother or baby, or both might help prevent transmission of HIV.

Breast Feeding↗
PubMed2002

Vitamin A and the nursing mother-infant dyad: evidence for intervention.

From the evidence at hand, interventions to reduce vitamin A deficiency in the breastfeeding mother and baby are likely to confer several health benefits. These include reduced puerperal morbidity, night blindness, and mortality in the mother, and reduced morbidity and mortality in the baby beginning around 6 months of age. Additional evidence is still needed to increase our confidence in these inferences, and to clarify the best interventions for achieving these outcomes. Current evidence about the effects of improved vitamin A status on early infant morbidity or mortality is mixed. There is accumulating evidence against the hypothesis that maternal vitamin A supplementation during pregnancy will reduce mother-to-child HIV transmission. There is so far no evidence about whether improved infant vitamin A status can prevent mother-to-child HIV transmission. In sum, the probable benefits of improving the vitamin A status of the breastfeeding mother and her baby are substantial, but to achieve these benefits, more aggressive interventions will be needed.

Adult↗
PubMed2002

Measuring performance: a strategy to improve programs.

This article stresses the importance of evaluation as a tool for improving the design and implementation of effective programs to reduce iron deficiency anemia and to advocate for their continued and increased support. Current concepts in program evaluation are applied to the specific issues relevant to iron programs. Evaluations should be designed to meet the needs of specific audiences (e.g., community members, program implementers, policymakers, donors and researchers) and to answer specific questions. Evaluations might answer questions about provision, coverage or impact. The choice of indicators for evaluating impact of iron programs is discussed and illustrated with recent examples. Evaluation design can be broadly categorized as monitoring, plausibility evaluations and probability evaluations. These designs differ in cost and also in the strength of evidence that they provide; however, each has appropriate uses. It is important to document program costs in the evaluation process as policymakers and donors weight impact against costs. To be useful, evaluation findings must be disseminated, usually to multiple audiences. This requires allocation of time and resources and attention to the needs of various stakeholders.

Adult↗
PubMedDate not supplied

Is the exclusion of children under 24 months from anthelmintic treatment justifiable?

There are no reports documenting toxicity or adverse effects after treatment of children aged < 24 months with benzimidazole derivatives and there is an urgent need to clarify this point in light of the potential detrimental effect that soil-transmitted helminthiasis has on this age-group. A total of 653 treatments (317 mebendazole 500 mg; 336 placebo) were administered in 1996/97 to 212 children aged < 24 months as part of a 1-year anthelmintic drug study conducted among preschool-age children in Tanzania. Data on fever, cough, diarrhoea, dysentery and acute respiratory illness were collected 1 week following the treatment. No differences between the occurrence of adverse effects in the 2 groups were observed. In light of the potential nutritional benefit achieved by regular deworming in this young age-group, the policy that excludes children aged < 24 months from treatment should be re-considered.

Anthelmintics↗