MedicalResearch.com Interview with: Prof. Scott Montgomery Professor of medical science (clinical epidemiology) Örebro University, Sweden Director of Clinical Epidemiology and Biostatistics Örebro University Hospital, Sweden MedicalResearch.com: What is the background for this study? Response: Infections have been linked with increased risk of subsequent multiple sclerosis (MS), but it has been suggested this may be because the genetic or other family characteristics of people who go on to develop MS have a more severe response to infections: the infections would be more likely to be recorded in those who would subsequently develop MS, rather than being risk factors for the disease. To address this issue, we performed a large study of 2,492,980 people living in Sweden, and 5,867 of them had a diagnosis of MS after age 20 years. We identified who had a hospital diagnosis of infectious mononucleosis (caused by Epstein-Barr virus, EBV infection, and also known as glandular fever or the kissing disease). The new study was different from other studies of infection and MS risk, as it compared siblings in the same families. Siblings share much of their genetic make-up and have similar family lives. If glandular fever is associated with later MS when siblings are compared, then it is unlikely that the association is caused by genetics or other family characteristics that make infections worse in people more likely to develop future MS. (more…)