PLoS ONE (Jan 2011)

Hepatitis B infection is associated with asymptomatic malaria in the Brazilian Amazon.

  • Bruno B Andrade,
  • Cristiane J N Santos,
  • Luís M Camargo,
  • Sebastião M Souza-Neto,
  • Antonio Reis-Filho,
  • Jorge Clarêncio,
  • Vitor R R Mendonça,
  • Nívea F Luz,
  • Erney P Camargo,
  • Aldina Barral,
  • Antônio A M Silva,
  • Manoel Barral-Netto

DOI
https://doi.org/10.1371/journal.pone.0019841
Journal volume & issue
Vol. 6, no. 5
p. e19841

Abstract

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BackgroundAreas that are endemic for malaria are also highly endemic for hepatitis B virus (HBV) infection. Nevertheless, it is unknown whether HBV infection modifies the clinical presentation of malaria. This study aimed to address this question.Methodology and findingsAn observational study of 636 individuals was performed in Rondônia, western Amazon, Brazil between 2006 and 2007. Active and passive case detections identified Plasmodium infection by field microscopy and nested Polymerase Chain Reaction (PCR). HBV infections were identified by serology and confirmed by real-time PCR. Epidemiological information and plasma cytokine profiles were studied. The data were analyzed using adjusted multinomial logistic regression. Plasmodium-infected individuals with active HBV infection were more likely to be asymptomatic (OR: 120.13, PConclusionHBV infection diminishes the intensity of malaria infection in individuals from this endemic area. This effect seems related to cytokine balance and control of inflammatory responses. These findings add important insights to the understanding of the factors affecting the clinical outcomes of malaria in endemic regions.