Underlying Factors Associated with Anemia in Amazonian Children: A Population-Based, Cross-Sectional Study

Background: Although iron deficiency is considered to be the main cause of anemia in children worldwide, other contributors to childhood anemia remain little studied in developing countries. We estimated the relative contributions of different factors to anemia in a population-based, cross-sectional survey. Methodology: We obtained venous blood samples from 1111 children aged 6 months to 10 years living in the frontier town of Acrelandia, northwest Brazil, to estimate the prevalence of anemia and iron deficiency by measuring hemoglobin, erythrocyte indices, ferritin, soluble transferrin receptor, and C-reactive protein concentrations. Children were simultaneously screened for vitamin A, vitamin B-12, and folate deficiencies; intestinal parasite infections; glucose-6-phosphate dehydrogenase deficiency; and sickle cell trait carriage. Multiple Poisson regression and adjusted prevalence ratios (aPR) were used to describe associations between anemia and the independent variables. Principal Findings: The prevalence of anemia, iron deficiency, and iron-deficiency anemia were 13.6%, 45.4%, and 10.3%, respectively. Children whose families were in the highest income quartile, compared with the lowest, had a lower risk of anemia (aPR, 0.60; 95% CI, 0.37-0.98). Child age (<24 months, 2.90; 2.01-4.20) and maternal parity (>2 pregnancies, 2.01; 1.40-2.87) were positively associated with anemia. Other associated correlates were iron deficiency (2.1; 1.4-3.0), vitamin B-12 (1.4; 1.0-2.2), and folate (2.0; 1.3-3.1) deficiencies, and C-reactive protein concentrations (>5 mg/L, 1.5; 1.1-2.2). Conclusions: Addressing morbidities and multiple nutritional deficiencies in children and mothers and improving the purchasing power of poorer families are potentially important interventions to reduce the burden of anemia.Sao Paulo State Research Agency [FAPESP 07/53042-1]Sao Paulo State Research AgencyNational Research Agency of BrazilNational Research Agency of Brazil [CNPq 470573/2007-4

Erratum to: The study of cardiovascular risk in adolescents – ERICA: rationale, design and sample characteristics of a national survey examining cardiovascular risk factor profile in Brazilian adolescents

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Human toxocariasis in rural Brazilian Amazonia: Seroprevalence, risk factors, and spatial distribution

This population-based cross-sectional study of 403 rural settlers in Brazilian Amazonia revealed an overall rate of IgG seropositivity to Toxocara canis excretory-secretory larval antigen of 26.8% (95% confidence interval [CI], 22.5-31.4%). Multilevel logistic regression analysis identified current infection with hookworm (odds ratio [OR], 2.32; 95% CI, 1.11-4.86) and residence in the most recently occupied sectors of the settlement (OR, 1.81.; 95%CI, 1.3-2.52) as significant risk factors for Toxocara seropositivity; age > 14 years (OR, 0.46; 95% CI, 0.28-0.73) and the presence of cats in the household (OR, 0.57; 95% CI, 0.32-1.02) appeared to be protective. Two significant high-prevalence clusters were detected in the area, together comprising 38.9% of the seropositive subjects; households in the clusters had slightly lower socioeconomic status and were less likely to have cats as pets. The obstacles for controlling human toxocariasis in this and other tropical rural settings are discussed

Iron status indicators and prevalence of anemia and other nutritional and non-nutritional conditions in urban Amazonian children^a.

<p>IQR, interquartile ranges.</p>a<p>Totals in brackets differ from the total number of study children by age group because of missing values.</p>b<p>Cut-offs for anemia: <110.0 and <115.0 g/L for 6–59 months and ≥60 months, respectively;</p>c<p>Cut-offs for microcytosis by age: <67, <73, <74, and <76 fl for <24 months, 24–59 months, 5–7.9 years, and 8–11.9 years, respectively;</p>d<p>PF: <12 and <15 µg/L for <59 and ≥60 months, respectively;</p>e<p>sTfR: >8.3 mg/L;</p>f<p>Cut-off for high CRP: >5 mg/L;</p>g<p>CRP index defined as (0.34+0.0043×PF – [2.7×sTfR]/PF+0.00696×CRP+0.05×sTfR);</p>h<p>Serum retinol <0.70µmol/L;</p>i<p>Serum vitamin B₁₂<150 pmol/L;</p>j<p>Serum folate <10 nmol/L;</p>k<p>According to cut-offs for PF or sTfR.</p>l<p>Geohelminths in this population included <i>Ascaris lumbricoides</i> (overall prevalence, 2.4%), <i>Strongyloides stercoralis</i> (0.5%), and <i>Trichuris trichiura</i> (0.8%) - the same subject may be co-infected with more than one species.</p