Rubella seropositivity in the United States, 1988-1994

Data obtained in the third National Health and Nutrition Examination Survey (NHANES III), conducted during 1988-1994, were analyzed to determine the e pidemiology of rubella seropositivity in the United States, including risk factors for low rubella seropositivity. Serological samples obtained from N HANES III study participants greater than or equal to6 years of age were te sted for rubella IgG antibodies. "Rubella seropositivity" was defined as se rum rubella IgG antibody level greater than or equal to 10 IU by enzyme imm unoassay. Overall, rubella seropositivity rates in the United States were 9 2% in persons aged 6-11 years, 83% in persons aged 12-19 years, 85% in pers ons aged 20-29 years, 89% in persons aged 30-39 years, and greater than or equal to 93% in persons aged greater than or equal to 40 years. The lowest rate (78%) of any United States birth cohort of the 20th century occurred a mong persons born from 1970-1974. Eliminating rubella and chronic rubella s yndrome in the United States will require international efforts, including vaccination of preschool- and school-age children and all susceptible young adults.