MULTIPLE SCLEROSIS: THE IMPACT OF INFECTION ON DISEASE PROGRESSION. VIRUSES AS A TRIGGERS OF MULTIPLE SCLEROSIS Historical overview Viral infections have been emphasized as the underlying etiology of MS since the early discovery of the disease. In 1868, Jean-Martin Charcot described MS for the first time 1 and argued vigorously that pathogenic infections underline the etiology of MS 2. Charcot's argument was inspired by the germ theory advocated by Louis Pasteur and Robert Koch, during the “golden era” of microbiology, which revealed the viral and bacterial origin of numerous known infectious diseases. Known for its antiviral properties, interferon was the first FDA-approved medication for the treatment of MS. In 1993, the FDA approved recombinant interferon beta (IFN β-1b) as the first disease-modifying therapy (DMT) for MS. In 1996, a phase III trial on the intramuscular IFN B-1a demonstrated the positive influence of DMT on the accumulating disability in MS 3. With Epstein-Barr