It is widely believed that multiple sclerosis is common in temperate areas and less common in subtropical and tropical regions. The evidence for this belief, however, is incomplete. Observations on the frequency of this disease have been made by different investigators using nonuniform case-finding techniques and varying diagnostic criteria. Moreover, only a few surveys are available from large areas of Asia, Africa, southern Europe, and most of the southern hemisphere. Additional estimates of frequency derived from standard procedures are needed to clarify the pattern of geographic distribution.
Israel offers unique advantages for studying the geographic distribution of multiple sclerosis. Its population is a mosaic of individuals who immigrated from 70 countries. No immigration restrictions were placed on individuals with neurological disease. The country has the highest physicianto-population ratio in the world, and all elements of the population have equal access to the same high-quality medical facilities. Political factors tend to
ALTER M, HALPERN L, KURLAND LT, BORNSTEIN B, LEIBOWITZ U, SILBERSTEIN J. Multiple Sclerosis in IsraelPrevalence Among Immigrants and Native Inhabitants. Arch Neurol. 1962;7(4):253–263. doi:10.1001/archneur.1962.04210040005001