Seroprevalence of rubella in the cord blood of pregnant women and congenital rubella incidence in Nha Trang, Vietnam

• DOI: 10.1016/j.vaccine.2013.08.076
• Publication Date: 2013-09-07T13:46:36Z
• Authors: Masami Miyakawa; Hiroshi Yoshino; Lay Myint Yoshida; Emilia Vynnycky; Hideki Motomura; Le Huu Tho; Vu Dinh Thiem; Koya Ariyoshi; Dang Duc Anh; Hiroyuki Moriuchi
• Keywords: Adult; Adolescent; Incidence; Rubella Syndrome, Congenital; Infant, Newborn; Middle Aged; Antibodies, Viral; Fetal Blood; Models, Biological; 3. Good health; 03 medical and health sciences; 0302 clinical medicine; Immunoglobulin M; Vietnam; Pregnancy; Seroepidemiologic Studies; Immunoglobulin G; Humans; Female; Rubella Vaccine; Prospective Studies; Pregnancy Complications, Infectious; Rubella

To investigate susceptibility to and factors associated with rubella infection among pregnant mothers and to estimate the burden of congenital rubella infection (CRI) in Vietnam where rubella-containing vaccine (RCV) is not included in the routine immunization program, we conducted a prospective cohort study in Nha Trang, Vietnam between 2009 and 2010. Rubella-specific immunoglobulin-M and immunoglobulin-G were investigated in cord blood samples by enzyme immunoassay. Corresponding clinical-epidemiological data were analyzed and the national congenital rubella syndrome (CRS) incidence was estimated using modeling. We enrolled 1988 pairs of mothers aged 17-45 years and their newborn babies. No mothers had received RCV. Multivariate analysis revealed that mothers aged 17-24 (aOR 2.5, 95% CI: 1.7-3.8) or 25-34 (1.4, 1.0-2.1) years were more likely to be susceptible than those aged 35-45 years. Overall 28.9% (574/1988, 95% CI: 26.9-30.9%) of mothers were seronegative. The CRI rate was 151 (95% CI: 0-322) per 100,000 live births. Modeling estimated that 3788 babies (95% CI: 3283-4143) were born with CRS annually in Vietnam with an overall CRS incidence of 234 (95% CI: 207-262) cases per 100,000 live births. A substantial proportion of women of childbearing age (WCBA) are at risk of rubella infection during pregnancy and this can result in a high frequency of miscarriage or burden of CRS across Vietnam. Prompt introduction of RCV into national immunization program with catch-up vaccination to children and WCBA will reduce CRI in Vietnam.