Seroprevalence of IgG Rubella among Infants with Features Suggestive of Congenital Rubella Syndrome at a Tertiary Hospital in North Western Tanzania

BACKGROUND: Congenital Rubella Syndrome (CRS) is among the causes of infant mortality and lifelong disability due to severe birth defects. There has been an increasing number of neonates born with congenital abnormalities suggesting CRS, at the same time the rubella seroprevalence among pregnant mothers and healthy school children in the northwestern Tanzania has been noted to be alarmingly high. This study aimed to determine prevalence of rubella antibodies and associated factors among infants suspected to have CRS. METHODS: This cross-sectional study included 174 infants aged ≤ 12 months with at least one clinical features of CRS. The study was conducted between Septembers 2017 and March 2018 at Bugando Medical Centre, a consultant teaching hospital in North Western Tanzania. Collection of Social demographic and other relevant information was done hand in hand with screening for clinical symptoms suggestive of CRS and Blood samples were collected. Indirect enzyme-linked immunosorbent assay (ELISA) Test were conducted on collected sera to test for specific Rubella IgM and IgG antibodies. RESULTS: The majority of enrolled infants were below 1 year of age; of these 83 (47.7%) were neonates and only 13.2% had received MR vaccine. Out of these, 111 (63.8%, 95%CI: 56.6-70.9) were IgG Rubella seropositive whereas none was IgM Rubella seropositive. In multivariate logistic regression analysis being neonate was the only factor that independently predicted rubella IgG seropositivity (OR 2.3; 95% CI 1.2 – 4.4; p=0.012). CONCLUSION: A significant proportion children (<12 months) with suspected CRS are IgG seropositive which is predicted by being a neonate (0-4weeks); this indicates high maternal seroprevalence and hence extended surveillance and measures to target women of child bearing age are recommended.