What Approaches are Most Effective at Addressing Micronutrient Deficiency in Children 0-5 Years? A Review of Systematic Reviews.

Introduction Even though micronutrient deficiency is still a major public health problem, it is still unclear which interventions are most effective in improving micronutrient status. This review therefore aims to summarize the evidence published in systematic reviews on intervention strategies that aim at improving micronutrient status in children under the age of five. Methods We searched the literature and included systematic reviews that reported on micronutrient status as a primary outcome for children of 0-5 years old, had a focus on low or middle income countries. Subsequently, papers were reviewed and selected by two authors. Results We included 4235 reviews in this systematic review. We found that (single or multiple) micronutrient deficiencies in pre-school children improved after providing (single or multiple) micronutrients. However home fortification did not always lead to significant increase in serum vitamin A, serum ferritin, hemoglobin or zinc. Commercial fortification did improve iron status. Cord clamping reduced the risk of anemia in infants up to 6 months and, in helminth endemic areas, anthelminthic treatment increased serum ferritin levels, hemoglobin and improved height for age z-scores. Anti-malaria treatment improved ferritin levels. Discussion Based on our results the clearest recommendations are: delayed cord clamping is an effective intervention for reducing anemia in early life. In helminth endemic areas iron status can be improved by anthelminthic treatment. Anti-malaria treatment can improve ferritin. In deficient populations, single iron, vitamin A and multimicronutrient supplementation can improve iron, vitamin A and multimicronutrient status respectively. While the impact of home-fortification on multimicronutrient status remains questionable, commercial iron fortification may improve iron status.

Intestinal parasites: Associations with intestinal and systemic inflammation.

The aim of the present study was to evaluate associations between intestinal parasitic infection with intestinal and systemic inflammatory markers in school-aged children with high rates of obesity. Plasma concentrations of C-Reactive Protein (CRP), leptin, TNF-α, IL-6 and IL-10 were measured as systemic inflammation markers and count of stool leukocytes as marker of intestinal inflammation in 291 children (6-10 years). Intestinal parasitic infection was measured by stool examination. Logistic regression analyses were performed to determine the odds of having high inflammatory markers for each parasite or group of parasites as compared to parasite-free children while adjusting for sex, age, mother's educational level and percentage of body fat. The prevalence of soil-transmitted helminths and intestinal protozoa infections was 12% and 36%, respectively. Parasitic infection was not associated with CRP, IL-6, IL-10 or TNF-α. Children infected with Ascaris lumbricoides (aOR: 5.91, 95% CI: 1.97-17.70) and Entamoeba coli (aOR: 8.46, 95% CI: 2.85-25.14) were more likely to have higher stool leucocytes than parasite-free children. Children with multiple infections (aOR: 10.60, 95% CI: 2.85-25.14) were more likely to have higher leptin concentrations than parasite-free children. Intestinal parasitic infection was not associated with systemic inflammation, but was associated with intestinal inflammation. Having multiple infections were associated with higher leptin concentrations.

Children with moderate-high infection with Entamoeba coli have higher percentage of body and abdominal fat than non-infected children.

BACKGROUND: Intestinal parasites, virus and bacterial infections are positively associated with obesity and adiposity in vitro and in animal models, but conclusive evidence of this relationship in humans is lacking. The aim of this cross-sectional study was to determine differences in adiposity between infected and non-infected children, with a high prevalence of intestinal parasitic infection and obesity. SUBJECTS: A total of 296 school-aged children (8.0 ± 1.5 years) from a rural area in Querétaro, Mexico, participated in this study. Anthropometry (weight, height and waist circumference) and body fat (DXA) were measured in all children. A fresh stool sample was collected from each child and analysed for parasites. Questionnaires related to socioeconomic status and clinical history were completed by caretakers. RESULTS: Approximately 11% of the children were obese, and 19% were overweight. The overall prevalence of infection was 61%. Ascaris lumbricoides was the most prevalent soil transmitted helminth (16%) followed by hookworm. Entamoeba coli was the predominant protozoa (20%) followed by Endolimax nana, Balantidium coli, Entamoeba histolytica/dispar, Iodamoeba bütschlii and Giardia lamblia. Children with moderate-heavy infection of E. coli had significantly higher waist circumference, waist-to-height ratio, body and abdominal fat than children not infected or with light-intensity infection (p < 0.05). CONCLUSION: These findings raise the possibility that a moderate or heavy infection with E. coli may contribute to fat deposition and thereby have long-term consequences on human health. Further studies are needed to better understand if E. coli contributes directly to fat deposition and possible mechanisms.

Prediction of Asthma by Common Risk Factors: A Follow-up Study in Cuban Schoolchildren

Objective: To determine which common risk factors, including environmental factors, are predictors for the development of asthma in Cuban schoolchildren. Methods: A longitudinal study was conducted in 1042 schoolchildren without asthma at baseline in 2 Cuban municipalities. Asthma status in 2007, diagnosed using the International Study of Asthma and Allergies in Childhood questionnaire, was related to a set of common risk factors assessed in 2003/2004 in a multivariable logistic regression model. Multiple imputation was used for missing values. The final prediction model was obtained by backward selection (P<.15). The model’s prognostic accuracy (R2) and discriminative ability (area under the receiver operating characteristic curve [AUC]) were assessed and internal validation by bootstrapping was performed. Results: A family history of atopic diseases (odds ratio [OR], 2.19; 95% CI, 1.19-4.04), allergic sensitization (OR, 1.83; 95% CI, 0.94-3.55), municipality (OR, 0.34; 95% CI, 0.15-0.74), and use of antibiotics in the child’s first year of life (OR, 1.66; 95% CI, 0.89-3.11) were predictors for asthma development. The model had an R2 of 8.0% and a moderate discriminative ability (AUC, 0.69; 95% CI, 0.60-0.78). Internal validation hardly influenced the model’s performance. Conclusions: Antibiotics use, genetic predisposition, and allergic sensitization were predictors of asthma in Cuban schoolchildren. Although known as common risk factors they could only partly predict asthma development. Poverty-related factors, such as low income and education, and parasitic infections, did not have an effect. Other or additional environmental predictors need to be identified, as these are potential targets for prevention and control of childhood asthma in affluent as well as nonaffluent countries (AU)

Objetivo: Determinar cuáles de los factores de riesgo habituales, incluyendo factores ambientales, tienen capacidad predictiva para el desarrollo de asma en población escolar cubana. Métodos: Estudio longitudinal realizado en una muestra de 1042 escolares cubanos, sin asma al comienzo del estudio, residentes en dos municipios. La presencia de asma en el año 2007, diagnosticada mediante el cuestionario ISAAC, se relacionó con la presencia de factores de riesgo habituales, presentes al inicio del estudio en los años 2003-2004 mediante un modelo de regresión logística multivariable. Se utilizó el criterio de imputación múltiple para los valores no registrados. El modelo final predictivo se obtuvo mediante selección retrógrada. Se evaluaron la capacidad predictiva del modelo (R cuadrada) y capacidad discriminante (Área bajo la curva ROC) y se realizó una validación interna mediante la técnica de muestreo “bootstrapping”. Resultados: Una historia familiar de enfermedades alérgicas (OR 2.19, 95%CI 1.19-4.04), la presencia de sensibilización frente a alérgenos comunes (OR 1.83, 95%CI 0.94-3.55), el municipio de residencia (OR 0.34, 95%CI 0.15-0.74), y el uso de antibióticos en el primer año del vida del niño (OR 1.66, 95%CI 0.89-3.11) fueron todos ellos factores predictivos del desarrollo de asma. La R cuadrada del modelo fue el 8,0% y poseía una moderada capacidad discriminativa (AUC 0.69, 95%CI 0.60-0.78). La validez interna influencia notablemente el funcionamiento del modelo. Conclusiones: Los antecedentes familiares de enfermedad alérgica, la sensibilización frente a alérgenos comunes y el uso de antibióticos en el primer año de vida fueron factores predictivos de la aparición de asma en los escolares cubanos, si bien solo fueron capaces de explicar en parte esta predisposición. Otros factores relacionados con un nivel socioeconómico bajo, como un nivel de ingresos o de educación bajos o las infecciones por parásitos, no tuvieron ningún efecto. Se hace por tanto necesario, identificar otros o adicionales factores predictivos ambientales, que sean también dianas de programas de prevención y control de la enfermedad asmática tanto en países de niveles económicos altos o bajos (AU)

Deworming is not a risk factor for the development of atopic diseases: a longitudinal study in Cuban school children.

BACKGROUND: Soil-transmitted helminth (STH) infections have been suggested to protect from allergic sensitization and atopic diseases. Consequently, anthelminthic treatment would increase the prevalence of atopic disease in STH endemic populations. OBJECTIVE: To investigate the effect of deworming on allergic sensitization and atopic diseases in Cuban schoolchildren. METHODS: We followed up 108 STH positive schoolchildren aged 5-13 in six-monthly intervals for 24 months. Four consecutive groups of, respectively, 104, 56, 68, and 53 STH positive children were used as 'untreated' reference groups to assess general time trends. STH infections were diagnosed by stool examination. Asthma, allergic rhinoconjunctivitis, and atopic dermatitis were diagnosed by International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and allergic sensitization by skin prick testing (SPT). At each time point, STH positive children were treated with one single dose of 500 mg mebendazole. RESULTS: After deworming, the frequency of asthma significantly decreased (P < 0.001) while the frequency of allergic rhinoconjunctivitis and atopic dermatitis was not affected (P = 0.129 and P = 0.751, respectively). The percentage of SPT positives temporarily increased (P < 0.001) and subsequently returned to nearly baseline values (P = 0.093). In the references groups, no change over time was observed in the proportion of children with allergic sensitization and atopic diseases (P > 0.05). CONCLUSION & CLINICAL RELEVANCE: Our results indicate that atopic diseases do not increase after anthelminthic treatment. Allergic sensitization on the other hand increases after deworming. As this increase appears only temporarily, deworming of schoolchildren does not seem to be a risk factor for the development of allergic sensitization, nor for atopic diseases.

Leishmania chagasi/infantum: further investigations on Leishmania tropisms in atypical cutaneous and visceral leishmaniasis foci in Central America.

In Central America, apparently genetically identical Leishmania chagasi/infantum parasites cause cutaneous (CL) and visceral leishmaniasis (VL), the latter being more frequent in young children. The present study investigated if there were pathology-related differences in virulence between Honduran CL and VL strains using Mediterranean L. infantum strains as a reference. Macrophage infectivity and serum sensitivity, properties thought to be associated with virulence, were similar between CL and VL strains from both regions. Attention focused on the genome organisation of genes for two candidate virulence factors: Leishmania mitogen activated protein kinase (LMPK) and cysteine proteinase b (Cpb). Interestingly, the Mediterranean strains exhibited restriction enzyme polymorphisms associated with tropism for both LMPK and Cpb genes whereas no differences were observed for the Honduran strains. We also report relative genetic homogeneity of the Honduran strains as compared to the Mediterranean strains and discuss it in terms of the probable origin for the Central American L. chagasi/infantum.

Echinococcosis: disease, detection and transmission.

Echinococcosis is one of the world's most geographically widespread parasitic zoonoses, with transmission occurring in tropical, temperate and arctic biomes. Most human infections are due to Echinococcus granulosus transmitted between domestic dogs and livestock, but this cosmopolitan species also cycles between wild carnivores (principally canids) and wild ungulates. The other species with significant zoonotic potential is E. multilocularis that occurs naturally in fox definitive hosts and small mammal intermediate hosts. These two species cause human cystic or alveolar echinococcosis respectively, which may be considered serious public health problems in several regions including developed countries. This review provides an introductory overview to the Supplement and summarises the biology and epidemiology of these two related cestodes with an emphasis on applied aspects relating to detection, diagnosis and surveillance in animal and human populations, and includes aspects of transmission ecology, and also considers aspects of community epidemiology and potential for control.

Multi-scale spatial analysis of human alveolar echinococcosis risk in China.

Risk factors for the transmission of Echinococcus multilocularis to humans operate at a range of spatial scales. Over a large area, such as China, regional scale risk is correlated with variation in climatic conditions because of its effect on the spatial distribution of landscapes that can support E. multilocularis transmission in wildlife hosts and the probability of egg survival. At a local scale of a few kilometres, or tens of kilometres, transmission risk is related to the spatial proximity of human populations and landscapes with active transmission. At the patch scale, when considering individual villages or households, human behavioural factors are important and for individuals genetic and immunological factors play a role. Satellite remote sensing can provide landscape information at a range of spatial scales and provide a spatial framework within which to examine transmission patterns. This paper reviews the application of remotely sensed data and spatial data analysis to develop a better understanding of disease transmission and shows how such data have been used to examine human alveolar echinococcosis infection patterns, at a range of spatial scales, in an endemic area in central China.