Sero-epidemiological Studies of Rubella in Japan

1. Possessing Rate of Neutralizing Antibody in Inhabitants of Kumamoto City

Abstract

As the first report of this series attempted to unveil the hitherto little known status of rubella infection in Japan, the authors presented here the results of a sero-epidemiological survey performed on inhabitants of Kumamoto city.
In that, serum samples were collected non-selectively from a total of 410 persons who visited the affiliated hospital of the Faculty of Medicine, Kumamoto University for whatever kind of laboratory tests between Jan. and Aug. in 1965. These sera were subjected to detections of neutralizing antibody to rubella virus.
The results were summed up as follows:
1. Possessing rate of the positive neutralizing antibody by age distribution: An appreciable rise of the rate started at 10 years of age, and reached a peak (about 60% at the highest) between 15 to 19. This figure is considerably lower* than reported statistics of large cities such as Osaka and New York.
Moreover, the rate was extremely low in such age brackets as 0-4 and 5-9. This suggests that there has been no epidemic of appreciable size in this city in the past ten years.
2. The antibody possessing rate by sex: In any age group, differences of worth mentioning by sex were not observed.