Micronutrient Deficiencies and Plasmodium vivax Malaria among Children in the Brazilian Amazon

Abstract

BackgroundThere is a growing body of evidence linking micronutrient deficiencies and malaria incidence arising mostly from P. falciparum endemic areas. We assessed the impact of micronutrient deficiencies on malaria incidence and vice versa in the Brazilian state of Amazonas.Methodology/Principal FindingsWe evaluated children <10 years old living in rural communities in the state of Amazonas, Brazil, from May 2010 to May 2011. All children were assessed for sociodemographic, anthropometric and laboratory parameters, including vitamin A, beta-carotene, zinc and iron serum levels at the beginning of the study (May 2010) and one year later (May 2011). Children were followed in between using passive surveillance for detection of symptomatic malaria. Those living in the study area at the completion of the observation period were reassessed for micronutrient levels. Univariate Cox-proportional Hazards models were used to assess whether micronutrient deficiencies had an impact on time to first P. vivax malaria episode. We included 95 children median age 4.8 years (interquartile range [IQR]: 2.3–6.6), mostly males (60.0%) and with high maternal illiteracy (72.6%). Vitamin A deficiencies were found in 36% of children, beta-carotene deficiency in 63%, zinc deficiency in 61% and iron deficiency in 51%. Most children (80%) had at least one intestinal parasite. During follow-up, 16 cases of vivax malaria were diagnosed amongst 13 individuals. Micronutrient deficiencies were not associated with increased malaria incidence: vitamin A deficiency [Hazard ratio (HR): 1.51; P-value: 0.45]; beta-carotene [HR: 0.47; P-value: 0.19]; zinc [HR: 1.41; P-value: 0.57] and iron [HR: 2.31; P-value: 0.16]). Upon reevaluation, children with al least one episode of malaria did not present significant changes in micronutrient levels.ConclusionMicronutrient serum levels were not associated with a higher malaria incidence nor the malaria episode influenced micronutrient levels. Future studies targeting larger populations to assess micronutrients levels in P. vivax endemic areas are warranted in order to validate these results.

Nutritional status of children with vivax malaria in the Amazon Basin

“…These data are in line with studies done in other endemic areas, which suggested that children living in these areas might have a deficit of linear growth [10,11,22,23]. Children with low height-for-age had a history of 1-3 episodes of malaria.…”

“…Thus, low social-economical level, the concurrent infectious diseases such viruses and intestinal parasites, as well as the deficit of macro or micronutrient may act synergistically on the nutritional status of local inhabitants [10,11,25]. Furthermore, the transversal design of the study instead of a prospective cohort study, did not allow comparisons over the time to determine the causality between poor nutritional status and malaria, which was considered the main limitation of the study.…”

“…The relation between malaria and nutritional status is controversial and complex once nutritional status influences the immune response to infection whereas the infection directly influences the nutritional status. Some studies have not found associations between the disease and the nutritional status whereas others have shown that the poor nutritional status has a significant impact on the morbidity and mortality due to malaria [9][10][11][12].…”

“…In Latin America, only a few studies evaluated the nutritional status of children with malaria and, only recently, the nutritional status of children with P. vivax malaria was associated with the disease in a prospective study in Western Amazon [10]. In a recent study, our research team has found significant changes in lipid levels of children in the acute phase of P. vivax malaria, which may occur with the poor nutritional status [13].…”

Cognitive performance of children living in endemic areas for Plasmodium vivax

“…The disease affects equally all ages groups and both genders, and children are considered at risk to develop more serious signals and symptoms due to their relative lack of adequate immune response [ 2 – 4 ]. In fact, adverse effects on immune and haematopoietic systems as well as on the nutritional status have been described in this age group [ 3 – 5 ].…”