Rubella in Seattle-King County Washington

Systematic Review of Measles and Rubella Serology Studies

Serological tests provide information about individual immunity from historical infection or immunization. Cross-sectional serological studies provide data about the age- and sex-specific immunity levels for individuals in the studied population, and these data can provide a point of comparison for the results of transmission models. In the context of developing an integrated model for measles and rubella transmission, we reviewed the existing measles and rubella literature to identify the results of national serological studies that provided cross-sectional estimates of population immunity at the time of data collection. We systematically searched PubMed, the Science Citation Index, and references we identified from relevant articles published in English. We extracted serological data for comparison to transmission model outputs. For rubella, serological studies of women of child-bearing age provide information about the potential risks of infants born with congenital rubella syndrome. Serological studies also document the loss of maternal antibodies, which occurs at different rates for the different viruses and according to the nature of the induced immunity (i.e., infection or vaccine). The serological evidence remains limited for some areas, with studies from developed countries representing a disproportionate part of the evidence. The collection and review of serological evidence can help program managers identify immunity gaps in the population, which may help them better understand the characteristics of individuals within their populations who may participate in transmission and manage risks.

Public health implications of rubella antibody levels in California

Rubella hemaggluttination inhibition (HI) antibody determinations were performed in 1977 on a sample of California school children and in 1977-1979 on young women who were about to be married or who were pregnant. Among the pupils, 66 per cent reported prior rubella immunization; immunization history was more common in younger pupils. Seventy-seven per cent had detectable antibody, with little trend of greater seropositivity at older ages. Over 86 per cent of those with a written record of immunization had detectable antibody. There was no consistent indication of loss of seropositivity with increasing time since immunization. Children immunized at 12-14 months of age tended to have a lower seropositivity rate than those immunized at older ages. Among young women, the prevalence of detectable antibody was 80-83 per cent. Comparison with data obtained in 1968-1969 indicates that rubella immunization has had a marked impact on antibody levels in children but less impact on levels in teenagers and adults. The pool of rubella-susceptibles entering secondary schools will probably not decrease soon, so that rubella outbreaks may continue in high school and college-age populations. Ultimately, school entry immunization requirements should drastically curtail disease activity. In the interim, programs to immunize teenagers and young adult females must be strengthened. (Am J Public Health 1982; 72:167-172.)