Disease burden of Congenital Rubella Syndrome at four referral hospital in Zambia

Abstract

Background: Congenital Rubella Syndrome (CRS) characterised by heart, eye and hearing defects usually affects an unborn baby when the mother is infected with Rubella virus in the first trimester of pregnancy. It is vaccine preventable and has been eliminated in certain parts of the world. In developing countries like Zambia, CRS unfortunately still carries a significant but unknown morbidity and mortality burden. We conducted a combined survey for retrospective and prospective occurrences at referral hospitals in Lusaka, Copperbelt and Southern provinces of Zambia to assess the burden of CRS in the three provinces. Methods: Data for 2010 to 2015 was obtained for the three provinces at University Teaching Hospital in Lusaka, Arthur Davison Children’s and Kitwe Central Hospitals on the Copperbelt, and Livingstone Central Hospital in Southern province. This included age and date on diagnosis, location, sex, type of diagnosis (laboratory or clinical), and associated manifestations (cataracts, congenital heart disease, etc.). Estimated incidence was calculated based on observed cases and Central Statistical Office population data for the provinces. Results: A total of 36 CRS cases (clinically confirmed) were identified. The median age was 9.5 months. About 47% (17/36) of the children were tested for Rubella specific IgM with only 31% (11/36) having valid results. About 19% (7/36) had Laboratory confirmed CRS with 43% (3/7) of these confirmed retrospectively and 57% (4/7) prospectively. The commonest clinical features were congenital cataracts, congenital heart disease (patent ductus arteriosus) and microcephaly. The commonest combined clinical features were congenital heart disease, congenital cataracts and microcephaly (14% {5/36}). Incidence was calculated for 2014 only as it had complete data. The incidence of CRS per 1, 000 live births was 0.13 for Lusaka, 0.06 for Copperbelt and 0.01 for Southern province. Conclusion: CRS is real and still remains a problem in Zambia causing significant morbidity. It is underestimated in Zambia partly due to poor clinical assessment and record keeping.