Incidence of tuberculosis among Scandinavian immigrants in Canada.

Tuberculosis incidence in Finland is at least five times higher than in the other Scandinavian countries. A study of the incidence of tuberculosis in immigrants to Canada from Finland and the other Scandinavian countries shows a remarkable similarity between the rates of the immigrants and those who remained in their country of origin, even after 40 years of residence in the new country. The early experience of tuberculosis thus predetermines future susceptibility throughout the life span of the group.