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Is multiple sclerosis (MS) caused by an infection?

Some data suggest that a common virus or other infectious agent may play a role in the cause of multiple sclerosis (MS). Whether it is a persistent viral infection or an immune reaction caused by a temporary viral infection in the central nervous system (CNS) or elsewhere in the body is not yet known. Environmental studies suggest that some factor -- probably infectious -- must be encountered before the age of 15 in order for MS to develop later in life. Several viruses and bacteria, including Epstein-Barr, Chlamydia pneumonia, measles, canine distemper, and human herpes virus-6 have been studied to determine if they may trigger MS.
Louis Rosner
Neurology

Today one of the most popular scientific theories is that multiple sclerosis (MS) is caused by viral infection. Actually, for the past one hundred years, scientists have suspected that MS is caused by a virus attack. Charcot's student and successor, Pierre Marie, first raised the possibility in 1884, and today many researchers still believe that a viral hypothesis can best explain the results of many MS studies. In other words, the viral theory seems to fit the other pieces of the MS puzzle.

The word virus comes from the Latin for "slimy liquid," "stench," or "poison." Most of us are familiar with acute viral diseases - such as the flu, a cold, or pneumonia - that hit and leave fairly quickly. These are not caused by the kind of viruses linked to MS. Research is pointing to "slow-acting viruses" that can stay inside the body for months or years before triggering illness. Three areas of investigation have given credence to this theory:

Migration studies indicate that MS is related primarily to environmental exposure in childhood followed by a long latency.

Animal studies have documented that viruses can evoke relapsing and remitting courses (often seen in MS) and can cause myelin destruction.

Studies of MS patients have consistently shown abnormal levels of viral antibodies, the substances the body produces to fight infection.

If a specific virus causes MS, it has yet to be found. At one time or another almost every virus has been investigated for MS, but research in this area still continues. Since 1946 twenty viruses have been studied, and in eleven, high antibody titers (strengths) have been found in the spinal fluid of people with MS. One of the most scrutinized is rubeola, the virus that causes measles.

Rubeola also causes another neurological disease called subacute sclerosing panencephalitis (SSPE) - a slowly progressive disease that occurs as a complication after measles but many years later. In SSPE, antibody levels against the measles virus are unusually high, and there is also demyelination.

Multiple Sclerosis

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Multiple Sclerosis

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.