MS EPIDEMIOLOGY - Nationwide, there are an estimated 250,000 to 350,000 people with MS
Epidemiology is the study of disease patterns that takes into account variations in geography, demographics, socioeconomic status, genetics, and infectious causes. Epidemiologists contribute to knowledge about MS by studying the relationships between these factors, as well as patterns of migration, that may be related to areas of with high or low rates of MS.
There appear to be multiple causes in MS, possibly including viruses and environmental, genetic, and immune system factors. Among the well-established epidemiological observations on MS are:
Worldwide, MS occurs with much greater frequency in higher latitudes (above 40ø latitude) away from the equator, than in lower latitudes, closer to the equator.
In the U.S., MS occurs more frequently in states that are above the 37th parallel than in states below it. From east to west, the 37th parallel extends from Newport News, VA, to Santa Cruz, CA?running along the northern border of North Carolina to the northern border of Arizona and including most of California. The MS prevalence rate for the region below the 37th parallel is 57 to 78 cases per 100,000 people. The prevalence rate for those above the 37th parallel is 110 to 140 cases per 100,000 people. Nationwide, there are an estimated 250,000 to 350,000 people with MS.
An individual who is born in an area with a higher risk of developing MS and moves to an area of lower risk, acquires the risk of the new home if the move occurs before the individual is 15 years old.
MS is more common among Caucasians (particularly those of northern European ancestry) than other races, and is almost unheard of in some populations, such as Eskimos.
MS is twice as common in women compared to men.
Certain outbreaks or clusters of MS have been identified, but their significance is not known.
In certain populations, a genetic marker has been linked to MS. A particular genetic trait occurs more frequently in people with MS than in those who do not have the disease.
These and other studies have contributed to the opinion that early exposure to an environmental agent might be a triggering factor in people who are predisposed by genetic factors to develop MS.
SOURCE: NMSS Information Resource Center and Library. Compendium of Multiple Sclerosis Information (CMSI). Æ 1997, National Multiple Sclerosis Society. Rev. 10/
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