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

Plasmodium spp. and Haemoproteus spp. infection in birds of the Brazilian Atlantic Forest detected by microscopy and polymerase chain reaction

In recent years haemosporidian infection by protozoa of the genus Plasmodium and Haemoproteus, has been considered one of the most important factors related to the extinction and/or population decline of several species of birds worldwide. In Brazil, despite the large avian biodiversity, few studies have been designed to detect this infection, especially among wild birds in captivity. Thus, the objective of this study was to analyze the prevalence of Plasmodium spp. and Haemoproteus spp. infection in wild birds in captivity in the Atlantic Forest of southeastern Brazil using microscopy and the polymerase chain reaction. Blood samples of 119 different species of birds kept in captivity at IBAMA during the period of July 2011 to July 2012 were collected. The parasite density was determined based only on readings of blood smears by light microscopy. The mean prevalence of Plasmodium spp. and Haemoproteus spp. infection obtained through the microscopic examination of blood smears and PCR were similar (83.19% and 81.3%, respectively), with Caracara plancus and Saltator similis being the most parasitized. The mean parasitemia determined by the microscopic counting of evolutionary forms of Plasmodium spp. and Haemoproteus spp. was 1.51%. The results obtained from this study reinforce the importance of the handling of captive birds, especially when they will be reintroduced into the wild

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

Attributable fractions (AF) of anemia according to age group in urban Amazonian children.

a<p>Prevalence (%) of cases exposed in each risk factors.</p>b<p>Adjusted prevalence ratio (aPR) estimated from multiple Poisson regression models with additional adjustment for age (in overall analysis), sex, wealth index (quartile), maternal schooling (≤4, 5–8, and ≥9 years), and maternal age (10–21, 22–35, and >35 years).</p>c<p>Attributable fraction defined as p(aPR –1)/aPR.</p

Multiple linear regression analysis of factors associated with hemoglobin in urban Amazonian children.

a<p>Total differs from total number of study children because of missing values.</p

General characteristics of children aged 6 months to 10 years (N = 1111).

a<p>Totals differ from the total number of study children because of missing values.</p