From The MS Information Sourcebook, produced by the National MS Society.
Many people with MS ask if their disease was caused by a virus or other infectious agent. Much research has focused on trying to answer to this question.
It is tempting to speculate on a viral cause for MS because viruses are known to cause demyelinating disease in animals and humans. Demyelination (destruction of myelin, the fatty sheath the surrounds and insulates nerve fibers in the central nervous system) causes nerve impulses to be slowed or halted and produces the symptoms of MS.
Data from epidemiological studies-those that analyze variations in geographical, socioeconomic, genetic, and other factors-suggest that exposure to an infectious agent may be involved in causing MS. Some viruses are known to have a long latency period between time of infection and appearance of clinical symptoms, as is thought to be the case in multiple sclerosis.
No Definitive to Link Any One Virus to MS
Looking at the Epstein-Barr Virus (EBV)
Increased antibodies to many different viruses have been found in the sera and cerebrospinal fluid of people with MS. This may not necessarily represent disease-causing infection by these viruses. It is more likely to be the result of non-specific immune activation. The role of a virus as a causative or triggering agent of MS remains speculative.
MS is Not Contagious
Kalb R. (ed.) Multiple Sclerosis: The Questions You Have; The Answers You Need (3rd ed.). New York: Demos Medical Publishing, 2004.
Murray TJ. Multiple Sclerosis: The History of a Disease. New York: Demos Medical Publishing, 2005.
Last updated March 2006