Seroprevalence of rubella antibodies among pregnant females in Sri Lanka.

The purpose of this study was to determine the seroprevalence of rubella antibodies among pregnant females in the Kalutara District of Sri Lanka, and to identify factors associated with susceptibility to rubella infection among pregnant females. A cross-sectional clinic-based study was conducted among 620 pregnant women attending antenatal clinics and residing in the district for more than one month. Data on the pregnant females and the socio-economic characteristics of the families were obtained using an interviewer-administered structured questionnaire. Three milliliters of blood was obtained to measure rubella-specific IgG antibody levels by ELISA (enzyme linked immunosorbent assay) tests. Overall, 76% of pregnant females were seropositive for rubella antibodies. Seropositivity in pregnant females increased with age. Susceptibility to rubella was significantly associated with rubella immunization status. Given the high susceptibility rate to rubella infection among pregnant females, it is imperative that any vaccination strategy in the short-term should focus on reducing the number of susceptible women of child-bearing age.