Prevalence of rubella-specific IgG antibodies in unimmunized young female population

CONTEXT Rubella is a mild self-limiting disease all over the world; nevertheless, it is of significant public health importance due to its teratogenic effect of congenital rubella syndrome. Rubella vaccine is currently not included in the national immunization program in India. Rubella-specific IgG in the unvaccinated population is a marker of previous rubella infection. Rubella IgG estimation in children will provide data for initiation and necessary modification to the immunization strategy. AIMS In this background, this study was conducted with an aim to know the age-specific susceptibility of acquiring rubella infections and future risk of congenital rubella syndrome (CRS) among girls. SETTINGS AND DESIGN This was a community-based, observational study. PARTICIPANTS AND METHODS The study was conducted at a randomly selected rural area Mavoor Panchayath of Kozhikode District, Kerala, among adolescent girls. The estimation of rubella-specific IgG antibody was done by quantitative enzyme-linked immunosorbent assay method. IgG titer value of >15 IU was taken positive, 8-15 IU as equivocal, and <8 IU as negative. STATISTICAL ANALYSIS USED Statistical analysis was performed using Statistical program for Social science version 16 for Windows. Chi-square test was applied to find out significant difference and Fisher's exact test wherever applicable. RESULTS The data and blood sample collection was done from 250 girls. The mean IgG titer was 151.93 ± 128.78 IU, and as per the criteria, 68.3% were positive, 28.5% were negative, and 3.2% were equivocal. At this age, majority (68.3%) of the girls get protection by natural infection without any vaccine. Some girls (32%) may remain susceptible to infection during adulthood and pregnancy. CONCLUSIONS Natural rubella infection was widely prevalent among child population and at this age. An immunization policy recommending rubella-containing vaccine is highly desirable to prevent rubella and CRS.