Rubella susceptibility in an adolescent female population.

A survey of 1,008 adolescent girls was performed to characterize adolescent rubella immunity, and susceptibility was defined as a hemagglutination antibody titer of less than 1:8 (the definition used by the Minnesota State Health Department and the pediatric literature). The incidence of rubella susceptibility was 9.1% in the study population and was evenly distributed with regard to current age, age at time of vaccination, and source of vaccination. In subjects with a history of rubella vaccination, 7.4% were susceptible, whereas in the unvaccinated population, the susceptibility rate was 31.7%. Because rubella is a relatively benign disease except when acquired by the fetus during pregnancy, and adolescents are not only approaching the traditional age of motherhood but also experiencing pregnancy in increasing numbers, it is important for physicians to substantiate the rubella susceptibility status of their adolescent female patients.