A previous study of the prevalence of multiple sclerosis (MS) in 1981 among immigrants from the United Kingdom and Ireland to Australia found that the prevalence for those with age at immigration (AAI) under 15 years of age did not differ from the older immigrants. We have reanalysed the original materials as well as census data for 1901-1981 for UKI and other high MS risk country immigrants. There was a highly significant trend in the prevalence rates of all Australians from New South Wales (NSW) to South Australia (SA) to Western Australia (WA) to Queensland (QLD). Rates by state among the Australian-born were almost identical to these, but there was no prevalence gradient for the UKI-born. The denominator population at risk of MS by AAI was calculated from special census tables of length of residence in Australia by age 0-79 in 1981 for UKI immigrants 1947-1981. The numerator was limited to the subset of 258 MS (Group II) also immigrating in 1947 and later, and age 0-79 in 1981. The absolute risk of MS for these migrants to the four states entering at age 0-14 was 22/100,000, significantly less than for all older age groups; age 15-39 immigrants had a risk of 54/100,000. Similar risk ratios for 0-14 versus 15-39 by state were 31 versus 61 (NSW), 29 versus 44 (QLD), 11 versus 50 (SA), 15 versus 51 (WA). © 2011 The Author(s).

Australia multiple sclerosis Risk Immigration Prevalence

multiple sclerosis Australia human trend study Longitudinal Studies middle aged birthplace risk assessment priority journal Aged Great Britain groups by age Young Adult population risk school child Humans Ireland Adolescent Infant, Newborn male Emigrants and Immigrants female Aged, 80 and over preschool child Infant Age of Onset Risk Factors Child, Preschool newborn prevalence Article major clinical study adult migration New Zealand Community Health Planning Age Factors United Kingdom Child