Frequency of Rubella Antibody among the Residents in NagasakiDistrict in SouthernJapan

A seroepidemiological survey for rubella antibody was undertaken with the sera collected from the residentsin Nagasaki district in southern Japan. Of 450sera tested, 144 (32 percent) were found not to have NT antibody. From the incidencesof NT antibody by age group, it was noticed that there are about 10 to 20 percent individualssusceptible to rubella virus infection in adults over 20 years old. This antibodydistribution pattern by age group and the distribution pattern of antibody titers suggestedthat the chance of infectionfrom rubella virus begins in childhoodand is considerablyfrequent in the adults around 20 years old in this district.