Abstract;

Introduction: Rubella virus (RV) infection in susceptible women during the first trimester of pregnancy is associated with congenital Rubella syndrome (CRS) characterized by deafness, heart diseases and cataracts. More than 100,000 children are born with CRS each year in the developing countries. Rubella sero-positivity among pregnant women has been reported to range from 54.1% to 95.2% in Africa. In Tanzania rubella IgG seropositivity ranges from 0.5% to 92.6% among pregnant women with limited data from Zanzibar. Despite the Rubella vaccine implementation among children in Tanzania, cases of active infection are still reported in Zanzibar. There is a need to embark on other vaccination strategies to reach a goal of CRS elimination, therefore it is important to generate information which might be useful in devising other control strategies. This study was conducted to determine the seropositivity and associated factors of Rubella virus IgG antibodies among pregnant women attending antenatal clinics in Unguja, ZANZIBAR.

Methodology: A cross-sectional study was involving 171 pregnant women attended different antenatal clinics in Unguja, Zanzibar conducted from May2023 to July2023. Sociodemographic and other relevant information were collected using structured questionnaires and blood samples was collected from each consented woman. Detection of rubella IgG antibodies was done by an indirect Enzyme Linked Immunosorbent Assay (ELISA) kit (Vircell, S.L. Parque Technologico de la Salud, Avicena 8, Spain). Data was entered into the Microsoft excel sheet for clearing and coding then analyzed by using Stata version 15.

Results: The median age of enrolled participants was 27 [IQR: 23-31] years. The overall seroprevalence of Rubella IgG antibodies was found to be 161/171(94.15%) [95% Cl:89%-96%] among pregnant women attended antenatal clinic at Mwembeladu and Rahaleo hospital in Unguja, Zanzibar. And the logistic regression analysis shown there was no statistical significantly factors which predicted seropositivity of Rubella IgG antibodies among pregnant women attended antenatal clinic in Unguja Zanzibar.

Conclusion: More than three quarter of pregnant women attended antenatal clinic at Mwembeladu and Rahaleo hospital in Unguja, Zanzibar are Rubella IgG seropositive being predicted by small business involvement and increase in age. Screening of rubella and emphasizing active immunization of women at risk are highly recommended in area with high non immune rate against rubella virus. More studies should be done to estimate the prevalence of Rubella virus IgG and understand the wider picture of Rubella in Zanzibar.