Although many people with MS have a history of infection, no single organism has been found in the blood and central nervous system of all people with MS. Some studies suggest that infection with one of several common viruses in the central nervous system may play a role. MS itself, however, is not contagious and cannot be transmitted through sexual contact. The results of the studies looking at the roles of toxins, allergens, and food have not been consistent, but these variables continue to be investigated.
Immune System Malfunction
Researchers favor the theory that MS is a disease of an immune system malfunction. Immune cells are involved in many diseases, including MS. These specialized blood cells, which are summoned to destroy foreign invaders, sometimes arrive in the central nervous system where they aren't normally found and damage the surrounding tissue. They appear to fail to recognize the myelin sheath, think it is a foreign substance, and mount an attack. This is referred to as an autoimmune response. This misdirected attack is also implicated in diseases such as lupus erythematosis and rheumatoid arthritis. Some evidence of an autoimmune reaction can be found when the blood, spinal fluid, and lesions of people with MS are tested.(published with permission in writing from:http://www.multiplesclerosis.com)
