Chapter 3 - Effect of infections on multiple sclerosis

Abstract

Evidence from both epidemiological and experimental studies, implicate infections present during childhood and young adulthood to the development and/or exacerbation of MS. Possible infectious agents include Epstein–Barr virus, human Herpesvirus-6, human endogenous retrovirus families, and coronavirus. In addition, common upper respiratory tract, gastrointestinal and urogenital tract bacterial infections have also been associated with MS exacerbations. In contrast, helminth infections appear to attenuate the course of MS, with effects extending beyond simple response to an infectious agent. Although the cause of MS in humans remains inconclusive, an infectious etiology is one possibility, as microbial agents may modulate the immune system in genetically susceptible individuals. Decoding the complex interaction between central nervous system cells, infections caused by various pathogens, and the immune response to those infections may improve our understanding of pathogenic mechanisms present in MS, and help develop new treatment strategies and/or prevent relapses.