RUBELLA is not endemic on Taiwan. This circumstance is unique for a densely populated area of over 13 million inhabitants undergoing rapid industrialization with daily arrivals of ships and airplanes from large population centers throughout the world. During the past 25 years rubella has occurred only in extensive island-wide epidemics in 1944, 1957 to 1958, and 1968.
In this brief discussion, I should like to present the macroepidemiology of the two most recent epidemics, which we were able to study, emphasizing two points: first, the interruption by the summer season of the spread of rubella throughout the island in 1968 as compared with 1957, and second, the high clinical and inapparent attack rates in schoolchildren not alive during the previous epidemic, with correspondingly low attack rates in the highly immune adult population. Studies of classroom and family spread are underway but will not be presented at this time.