Rubella seroprevalence among women of childbearing age in Tunis, Tunisia.

Abstract

Background: Rubella is considered as a benign childhood infection. Congenital rubella syndrome (CRS) can result from the virus's teratogenic potential, making the infection dangerous for pregnant women, particularly in the first trimester. Immunization is the only effective prevention against rubella and CRS in the absence of specific treatment. Since 2005, the rubella vaccine has been available in Tunisia. This study aimed to assess, eighteen years after the implementation of the program's vaccination in the country, its effect on rubella seroprevalence in women of reproductive age.

Methods: This retrospective cross-sectional study was performed from January 2021 to December 2023 at Aziza Othmana Hospital (Tunis), which has one of the biggest obstetrical and assisted medical procreation units in Tunisia. Each woman consulting in one of these two units was screened for rubella-IgG antibodies by electrochemiluminescence assay using the Elecsys Rubella IgG Kit and the Cobas e411 analyzer (Roche Diagnostics^®, Mannhein). Woman was considered immunized when titer of IgG was ≥ 10 UI/mL. All samples with titers over 500 UI/mL were tested for specific IgM by the same method.

Results: During the study period, 1652 women were enrolled; their age ranged from 18 to 46 years old (33.4 ± 5.3 years). Overall, the proportion of women who were protected against rubella was 93.9%; it was significantly higher among those who were part of the immunization programs (96.6% vs. 93.2%; p = 0.01). The median level of Rubella IgG in this first group was 175 ± 159 IU/mL. Women, who were not caught up by the strategy of vaccination, were seronegative in 6.8% of cases. Rubella IgM antibodies were negative in all the 143 cases tested excluding recent infection.

Conclusion: These findings demonstrate the effectiveness of the rubella vaccine, which is administered systematically as part of the national immunization schedule in all one-year-old infants. Nonetheless, the persistent vulnerability for rubellain susceptible women in their reproductive years highlights the importance of their vaccination during the pre-conception or in early postpartum phases.

Clinical trial: Not applicable, as this study is not a clinical trial.