On the Risk of Multiple Sclerosis According to Age at Immigration to South Africa*
On the Risk of Multiple Sclerosis According to Age at Immigration to South Africa*
复制标题
根据移民南非时的年龄，了解多发性硬化症的风险*
作者：
G. Dean;J. Kurtzke
在南非共和国根据 1960 年人口普查日开展的一项全国多发性硬化症 (M.S.) 患病率研究中，有 118 名多发性硬化症患者。出生于北欧（英国以及北欧和中欧其他地区）并于 1960 年移居共和国的人。他们的患病率为每 10 万移民中 49 人，而在土生土长的讲英语的南非白人中，患病率为每 10 万移民 11 人。为了研究移民年龄可能产生的影响，有必要将 M.S.移民到适当的分母——根据移民年龄划分的风险人口。在人口普查局（1960 年）的协助下，通过两种间接方式对移民年龄面临风险的人口进行了估算，并通过 1968-9 年面临风险的人口调查进行了估算。这两项研究都表明，罹患多发性硬化症的风险。对于 15 岁或 16 岁以下移民的人来说，M.S. 的风险降低到了预期风险的三分之一以下。这项研究进一步证明了 M.S.是一种获得性外源性疾病，其确切性质仍不确定，但根据目前的知识，慢病毒、潜伏病毒或温和病毒是其主要竞争者。
In a national prevalence study of multiple sclerosis (M.S.) in the Republic of South Africa based on census day 1960 there were 118 individuals with M.S. who were born in Northern Europe (United Kingdom and other parts of North and Central Europe) and who had emigrated to the Republic by 1960. Their prevalence rate was 49 per 100,000 immigrants in comparison with a prevalence of 11 per 100,000 among native-born English-speaking white South Africans. To study the possible effect of age at immigration it was necessary to relate the M.S. immigrants to the appropriate denominator—the population at risk according to age at immigration. The population at risk by age at immigration has been estimated by two methods in an indirect fashion with the assistance of the Bureau of Census (1960) and by surveys of the population at risk 1968-9. Both studies suggest that the risk of developing M.S. was reduced to less than a third of the expected risk among those who immigrated under the age of 15 or 16. This study is further evidence that M.S. is an acquired exogenous disease, the precise nature of which is still not certain but, according to present knowledge, has as its leading contender the class of slow, latent, or temperate viruses.