A Seroepidemiologic Study on Rubella Antibody in Pregnant Women in Kyonggi Do

Ki, Moran; Choi, Boyoul; Shin, Young Jeon; Park, Hung Bae; Youn, Bae Joong; Hahn, Joong Surk

Abstract

The vaccinations of susceptible children and postpubertal females are the major means to prevent congenital rubella syndrome(CRS). Another means for reducing the CRS is therapeutic abortion or fetal monitoring for women who are infected in the first four months of pregnancy. We couldnt estimate the incidence of CRS in Korea, because there was no surveillance system for rubella and CRS. Nationwide vaccination program for 15months infant had been started early 1980s. So, most women at childbearing age during study period were not received rubella vaccination. We set forth CRS management system for pregnant women in two rural county of Kyonggi province, Korea. In this system, the presence of rubella IgG and IgM antibodies for early pregnant women were examined with MEIA(Microparticle Enzyme Immunoassay) method by IMx automated analyzer Abbott. The infected pregnant women followed up in order to confirm their children CRS. This study was carried out from Mar.1993 to Jun.1994, and pregnant women examined were 874 persons. The results were summarized as follows. The overall positive rate of rubella IgG antibody was 94.5%(826/874). The positive rate was significantly increase as the age increased, and reached 100% in pregnant women who were over 35 years old. This results suggest that a meaningful number of women are infected during childbearing years. The geometric mean titer of IgG of sero-positive subjects was significantly declined as the age increased. On the question about history of URI symptoms and rash in pregnancy, 20.7% of respondents checked on URI symptoms with rash, 13.5% only URI symptoms without rash, and 65.8% no symptoms. However there was no demonstrable association between the rubella like infection history in pregnancy and the rubella IgG and IgM antibody status. Rubella infection rate in pregnant women was 0.9%(95% CI 0.4-1.8%). Two of these 8 infected pregnancies were terminated by therapeutic abortion. One of them was not followed. Five babies had no gross anomalies at birth. In Dec.1996, three of five babies were normal appeared infants. Two of them were not followed. Throughout this study results, we confirmed the need of CRS management system for pregnant women, in Korea.