Materials and methods: A cross sectional study was carried out among 285 women aged between 15 and 49 years. Enzyme-Linked Immunosorbent Assay (ELISA) method was used to detect and quantify human immunoglobulin G (IgG) antibodies with avidity for rubella virus in sera of participants. Socio-demographic characteristics of the participants, along with recent and previous history of fever and rash among others were obtained using a questionnaire. Statistical analysis was carried out using the program statistical package for social sciences (SPSS) version 16.

Results: Seroprevalence of rubella IgG among women of reproductive age in Ilorin was 92.3% (95% CI: 89.2%-95.4%). Thus susceptibility rate to rubella infection was 7.7%. Majority (87.1%) of the IgG seropositive participants had high rubella IgG avidity, implying past rubella infection or re-infections. Seroprevalence was significantly higher among participants from lower educational and socio-economic classes compared with other participants (P=0.035 & 0.023 respectively). There was a negative correlation between age and rubella specific IgG titer (p=0.000). Thus rubella specific IgG titer decreases with increasing age.

Conclusion: there is need for vaccination of susceptible women of reproductive age in Ilorin as the rubella susceptibility rate was higher than the 5.0% target set by the World Health Organization (WHO) for prevention of Congenital Rubella Syndrome (CRS).