Multiple sclerosis frequency in Israel's diverse populations.

BACKGROUND Israel has served for almost half a century as a site for epidemiologic studies of multiple sclerosis (MS). Its small geographic size, well-equipped, accessible, and subsidized health facilities, trained physicians, detailed census data, and a National MS Register, maintained since 1960, offer advantages for accurate determinations of MS frequency in its diverse populations. METHOD The authors calculated age-specific prevalence of MS in Israeli-born Jewish inhabitants, immigrant Jews from Europe/America and from North Africa/Asia, Israeli-born Christian and Moslem Arabs, Druze, and Bedouins. RESULTS Prevalence rate of MS per 10(5) population on June 30, 2000, for each of these groups in the order listed was 61.6, 53.7, and 27.9 for the Jewish groups and 35.3, 14.7, 10.9, and 17.3 for the non-Jewish groups. Three tiers in MS prevalence were apparent. The highest rates were in Israeli-born Jews and in Jewish immigrants from Europe/America (significantly higher in the former than the latter). Jewish immigrants from African/Asian countries and Christian Arabs had intermediate MS rates (significantly lower than in the first two groups but not significantly different from each other). Moslem Arabs, Druze, and Bedouins had the lowest rates of MS (significantly lower than in the intermediate group but not significantly different from each other). CONCLUSION Diverse ethnic groups living in the same geographic area may have significantly different frequencies of MS.