Rubella antibody avidity among rubella seropositive women attending a tertiary care facility in Nigeria

Abstract

Objectives: The aim of this study was to determine the seroprevalence of rubella virus antibodies among women of reproductive age group and assess risk factors of rubella infection. 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 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 reinfections. Seroprevalence was significantly higher among participants from lower educational and socio-economic classes compared with other participants (P = .035 and P = .023, respectively). There was a negative correlation between age and rubella specific IgG titer (P = .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).