Association between anemia and subclinical infection in children in Paraíba State, Brazil

With subclinical infection, serum iron concentrations are reduced, altering the synthesis of hemoglobin, the main indicator of anemia.

To evaluate the association between subclinical infection and anemia in children of Paraíba State.

This is a cross-sectional study involving 1116 children aged 6 to 59 months from nine municipalities of Paraíba State. Demographic and socioeconomic data were collected by means of a specific questionnaire. The C-reactive protein and hemoglobin levels were determined by the latex agglutination technique and automated counter, respectively. C-reactive protein values ≥ 6 mg/L were used as indicative of subclinical infection, while the presence of anemia was determined by hemoglobin values < 11.0 g/dL. The data were analyzed using the Epi Info computer program, with significance being set at 5%.

Data from this research showed that 80.1% of the children belonged to families that were below the bread line, with per capita income < ½ of the minimum wage at that time (R$ 350.00 approximately US$ 175.00). The prevalences of subclinical infection and anemia were 11.3% and 36.3%, respectively. Subclinical infection was significantly associated with anemia (p-value < 0.05). There were lower levels of hemoglobin in children with C-reactive protein ≥ 6 mg/L, with a mean hemoglobin level in children with subclinical infection of 10.93 g/dL (standard deviation - SD = 1.21 g/dL) and without infection of 11.26 g/dL (SD = 1.18 g/dL) (p-value < 0.05).

Anemia is associated with subclinical infection in this population, indicating that this is an important variable to be considered in studies of the prevalence of anemia in children.