13 SUSCEPTIBILITY OF URBAN ADOLESCENT OBSTETRICAL POPULATION TO RUBELLA

Abstract

Recent surveys, following the introduction of the USA rubella immunization program in 1969, have noted that 66-70% of the rubella cases are occuring in individuals 15 yrs. or older. Current estimates are that 20-30% of 10-19 yr. old females are without rubella antibody. A retrospective study was undertaken to document rubella susceptibility in an urban, low-income adolescent obstetrical population ranging in age from 12-16 yrs. Records were reviewed for all 177 patients (97% black) attending the Adol. OB Clinic from 9/73 to 10/80. Forty-six incomplete charts were excluded. Chart assessment included documentation of age; race; gestational age at first visit; rubella immunization history (as determined by prior health records, immunization cards and/or maternal history of immunizations); and rubella titers. Rubella Hemagglutination Inhibition (HI) titers were determined on a twofold dilution method by the Univ. Serology lab; an HI antibody test of less than 1:10 or non-reactive was considered indicative of susceptibility to rubella. Of the OB adolescent population, urban and predominantly black, 28% (34/131) were serologically susceptible to rubella. It is unclear whether the critical factor in susceptibility was the duration of vaccine-induced immunity or primary vaccine failure. To increase the level of protection in this high risk group, recommendations include: routine booster immunization with family planning for non-pregnant, seronegative adolescents and/or postpartum vaccination in seronegative teenagers.