Multiple Sclerosis and Epstein-Barr Virus

OBJECTIVE: To evaluate the epidemiological evidence for an etiological role of Epstein-Barr virus in multiple sclerosis (MS). DATA SOURCES: MEDLINE and Cochrane Library searches of the medical literature identified 24 studies. DATA EXTRACTION: 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. DATA SYNTHESIS: 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.