Rubella seronegativity in a low socioeconomic adolescent female population

Ninety low socioeconomic adolescent females (aged 16-22 years, means 18.6 years) were screened for rubella immunity using a rubella IgG enzyme immunoassay. Data concerning past immunizations (with documentation, if possible), prior rubella disease, and previous pregnancies were gathered through direct interviews. Results revealed 20 percent (18/90 girls) were seronegative. Fifty-eight percent (42/72) of the seropositive girls and 50 percent (9/18) of the seronegative girls gave verbal reports of previous rubella immunization, but only 11 subjects (12.2%) could provide documentation of previous vaccination, including one seronegative subject. Thirty-one percent (28/90) of the study population had a history of one or more previous pregnancies (22 therapeutic abortions, 10 live births, and 8 spontaneous abortions). A comparison of the seronegativity rate between the 28 girls who were pregnant previously and the 62 girls who were never pregnant demonstrated a significantly higher seronegativity rate among those who had been pregnant (29% vs. 16%; chi 2 = 5.51; p less than 0.05). The results of this study suggest that the seronegativity rate in this age group is consistent with previous reports of rubella immunity, few adolescents can provide documentation of rubella vaccination, and presentation for abortion is an optimal time to vaccinate rubella susceptible females.