title: P. vivax malaria and dengue fever co-infection: a cross-sectional study in the Brazilian Amazon.
abstract: BACKGROUND
  Malaria and dengue are the most prevalent vector-borne diseases worldwide and represent major public health problems. Both are endemic in tropical regions, propitiating co-infection. Only few co-infection cases have been reported around the world, with insufficient data so far to enhance the understanding of the effects of co-infection in the clinical presentation and severity.
  
  
  RESULTS
  A cross-sectional study was conducted (2009 to 2011) in hospitalized patients with acute febrile syndrome in the Brazilian Amazon. All patients were submitted to thick blood smear and PCR for Plasmodium sp. detection, ELISA, PCR and NS1 tests for dengue, viral hepatitis, HIV and leptospirosis. In total, 1,578 patients were recruited. Among them, 176 (11.1%) presented P. vivax malaria mono-infection, 584 (37%) dengue fever mono-infection, and 44 (2.8%) were co-infected. Co-infected patients had a higher chance of presenting severe disease (vs. dengue mono-infected), deep bleeding (vs. P. vivax mono-infected), hepatomegaly, and jaundice (vs. dengue mono-infected).
  
  
  CONCLUSIONS
  In endemic areas for dengue and malaria, jaundice (in dengue patients) and spontaneous bleeding (in malaria patients) should raise the suspicion of co-infection. Besides, whenever co-infection is confirmed, we recommend careful monitoring for bleeding and hepatic complications, which may result in a higher chance of severity, despite of the fact that no increased fatality rate was seen in this group.
authors.affiliation: Universidade do Estado do Amazonas, Manaus, Brazil; Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.
authors.forename: Belisa M L
authors.initials: BM
authors.lastname: Magalhães
authors.affiliation: Universidade do Estado do Amazonas, Manaus, Brazil.
authors.forename: André M
authors.initials: AM
authors.lastname: Siqueira
authors.affiliation: Universidade do Estado do Amazonas, Manaus, Brazil; Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.
authors.forename: Márcia A A
authors.initials: MA
authors.lastname: Alexandre
authors.affiliation: Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.
authors.forename: Marcela S
authors.initials: MS
authors.lastname: Souza
authors.affiliation: Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.
authors.forename: João B
authors.initials: JB
authors.lastname: Gimaque
authors.affiliation: Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.
authors.forename: Michele S
authors.initials: MS
authors.lastname: Bastos
authors.affiliation: Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.
authors.forename: Regina M P
authors.initials: RM
authors.lastname: Figueiredo
authors.affiliation: Universidade do Estado do Amazonas, Manaus, Brazil; Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.
authors.forename: Gisely C
authors.initials: GC
authors.lastname: Melo
authors.affiliation: Universidade do Estado do Amazonas, Manaus, Brazil; Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.
authors.forename: Marcus V G
authors.initials: MV
authors.lastname: Lacerda
authors.affiliation: Universidade do Estado do Amazonas, Manaus, Brazil; Fundação de Medicina Tropical Dr. Heitor Vieira Dourado, Manaus, Brazil.
authors.forename: Maria P G
authors.initials: MP
authors.lastname: Mourão
mesh_terms: D000328:Adult; D000368:Aged; D001938:Brazil / Q000453:epidemiology; D060085:Coinfection / Q000453:epidemiology*; D003430:Cross-Sectional Studies; D003715:Dengue / Q000150:complications / Q000453:epidemiology*; D005260:Female; D006801:Humans; D016780:Malaria, Vivax / Q000150:complications / Q000453:epidemiology*; D008297:Male; D008875:Middle Aged; D011247:Pregnancy