Abstract:
Background: Rubella primary infection during early stages of pregnancy is associated with high risk of congenital
Rubella syndrome (CRS). Prevention of CRS in the resource-limited countries requires multiple strategies. Here, we
document the data on the magnitude of Rubella natural immunity among adolescent girls which is a crucial group in
devising effective control strategies to prevent CRS.
Methods: A cross sectional study involving 397 adolescent girls was conducted in the city of Mwanza involving five
secondary schools. Socio-demographic and other relevant information were collected using pre-tested data collection
tool. Rubella IgG antibodies were determined using enzyme immunoassay. The presence of Rubella IgG titers of >10 IU/ml
indicated natural immunity.
Results: The mean age of the study participants was 15.18 ± 1.48 years. Of 397 girls, 340 (85.6%) and 57 (14.4%) were from
secondary schools representing peri-urban and rural areas, respectively. Out of 397 girls, 90.4% (95% CI: 87-93) were found
to be naturally immune with median Rubella IgG antibodies titers of 56.7 IU/ml interquartile range (IQR): 40.8-137. The
median Rubella IgG antibodies titers were significantly high in adolescent girls from families with high socio-economic
status (63.96 vs. 47.13 IU/ml, P < 0.001) and in adolescent girls from peri-urban areas of the city (63.33 vs. 39.9 IU/ml, P < 0.001).
Conclusion: The majority of adolescent girls in the city of Mwanza are naturally immune to Rubella virus. There is a need to
compare the effectiveness of screening and vaccinating susceptible adolescent girls with the effectiveness of vaccinating all
women of childbearing in controlling CRS in low-income countries.
