title: Epstein-Barr virus in healthy individuals from Portugal.
abstract: BACKGROUND
  The Epstein-Barr virus (EBV) persists for long periods in latent state inside B-lymphocytes after primary infections, and reactivation usually occurs associated to immunosuppression conditions of the host. Recently, the detection of EBV DNA in circulation has been suggested as a predictor marker for the development of EBV related malignancies.
  
  
  OBJECTIVE
  The aim of our study was to characterize the frequency of circulating EBV in healthy individuals (n=508) from the North region of Portugal, using peripheral blood samples. Detection was performed by Nested-PCR which amplifies a fragment from the BamHIW region of the EBV genome.
  
  
  RESULTS
  Our results revealed an overall frequency of 37.2% positive cases for EBV in circulation, with distinct distribution according to genre (39.7% in male individuals and 33.2% in females). We also found that EBV is more frequent in individuals with more than 56 years old compared to individuals with less than 56 years old (p=0.032; RR=1.41), mainly in the male group (p=0.024; OR=1.51).
  
  
  CONCLUSIONS
  This is the first study which characterizes the frequency of EBV in circulation in healthy donors from the Northern Region of Portugal, revealing increased frequency of EBV in circulation in healthy individuals with differences depending on gender or age. Further studies are required to analyze the role of circulating EBV in the definition of susceptibilities to EBV associated diseases.
authors.affiliation: Molecular Biology Laboratory of Virology Service, Portuguese Institute of Oncology of Porto, Portugal.
authors.forename: Hugo
authors.initials: H
authors.lastname: Sousa
authors.forename: João
authors.initials: J
authors.lastname: Silva
authors.forename: Luís
authors.initials: L
authors.lastname: Azevedo
authors.forename: Ana L
authors.initials: AL
authors.lastname: Pinto-Correia
authors.forename: Raquel
authors.initials: R
authors.lastname: Catarino
authors.forename: Daniela
authors.initials: D
authors.lastname: Pinto
authors.forename: Carlos
authors.initials: C
authors.lastname: Lopes
authors.forename: Rui
authors.initials: R
authors.lastname: Medeiros
mesh_terms: D000328:Adult; D005260:Female; D006304:Health Status; D004854:Herpesvirus 4, Human / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011174:Portugal; D012189:Retrospective Studies; D055815:Young Adult