title: Micronutrient Deficiencies and Plasmodium vivax Malaria among Children in the Brazilian Amazon.
abstract: BACKGROUND
  There 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.
  
  
  RESULTS
  We 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.
  
  
  CONCLUSIONS
  Micronutrient 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.
authors.affiliation: Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Brazil.
authors.forename: Silvana Gomes
authors.initials: SG
authors.lastname: Benzecry
authors.affiliation: Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Brazil.|Gerência de Malária, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.
authors.forename: Márcia Almeida
authors.initials: MA
authors.lastname: Alexandre
authors.affiliation: Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Brazil.|Gerência de Malária, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.
authors.forename: Sheila
authors.initials: S
authors.lastname: Vítor-Silva
authors.affiliation: Division of Infectious Diseases, Department of Medicine, Emory University, Atlanta, United States of America.
authors.forename: Jorge Luis
authors.initials: JL
authors.lastname: Salinas
authors.affiliation: Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Brazil.|Gerência de Malária, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.
authors.forename: Gisely Cardoso
authors.initials: GC
authors.lastname: de Melo
authors.affiliation: Laboratório de Nutrição, Instituto Nacional de Pesquisas da Amazônia, Manaus, Brazil.
authors.forename: Helyde Albuquerque
authors.initials: HA
authors.lastname: Marinho
authors.affiliation: Applied Statistics, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Ângela Tavares
authors.initials: ÂT
authors.lastname: Paes
authors.affiliation: Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Brazil.|Gerência de Malária, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.|Instituto Nacional de Infectologia Evandro Chagas, Rio de Janeiro, Brazil.
authors.forename: André Machado
authors.initials: AM
authors.lastname: de Siqueira
authors.affiliation: Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Brazil.|Gerência de Malária, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.
authors.forename: Wuelton Marcelo
authors.initials: WM
authors.lastname: Monteiro
authors.affiliation: Escola Superior de Ciências da Saúde, Universidade do Estado do Amazonas, Manaus, Brazil.|Gerência de Malária, Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.|Instituto de Pesquisas Leônidas & Maria Deane, Fundação Oswaldo Cruz, Manaus, Brazil.
authors.forename: Marcus Vinícius Guimarães
authors.initials: MV
authors.lastname: Lacerda
authors.affiliation: Department of Pediatrics, Discipline of Nutrition and Metabolism, Federal University of São Paulo, São Paulo, Brazil.
authors.forename: Heitor Pons
authors.initials: HP
authors.lastname: Leite
mesh_terms: D001938:Brazil / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007501:Iron / Q000097:blood; D000090463:Iron Deficiencies; D016780:Malaria, Vivax / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology*; D008297:Male; D018977:Micronutrients / Q000097:blood / Q000172:deficiency*; D015596:Nutrition Assessment; D010966:Plasmodium vivax / Q000302:isolation & purification*; D016016:Proportional Hazards Models; D012424:Rural Population; D014802:Vitamin A Deficiency / Q000097:blood / Q000150:complications*; D015032:Zinc / Q000097:blood / Q000172:deficiency*; D019207:beta Carotene / Q000097:blood / Q000172:deficiency*
chemical_list: D018977:Micronutrients; D019207:beta Carotene; D007501:Iron; D015032:Zinc