title: Multiple sclerosis and Epstein-Barr virus.
abstract: OBJECTIVE
  To evaluate the epidemiological evidence for an etiological role of Epstein-Barr virus in multiple sclerosis (MS).
  
  
  METHODS
  MEDLINE and Cochrane Library searches of the medical literature identified 24 studies.
  
  
  METHODS
  Studies were categorized as seroepidemiological, case-control or historical cohort, and were then classified within each group according to methodological rigour using criteria derived from published guidelines for the epidemiological study of MS.
  
  
  RESULTS
  There was significant variability in the quality of evidence, and while two well-designed cohort studies found increased relative risks of MS in subjects with infectious mononucleosis, results from other studies were unconvincing.
  
  
  CONCLUSIONS
  The evidence was insufficient to accept or reject the hypothesis that Epstein-Barr virus has an etiological role in MS. Further study, ideally using large samples of incident cases with blinded, trained interviewers using confirmatory sources for recalled data, is needed.
authors.affiliation: Montreal Neurological Institute, McGill University.
authors.forename: Ruth Ann
authors.initials: RA
authors.lastname: Marrie
authors.forename: Christina
authors.initials: C
authors.lastname: Wolfson