Abstract
INTRODUCTION: Since establishing routine immunization services in what was then known as Sudan in 1974, South Sudan has not yet introduced the rubella-containing vaccine into its national immunization schedule. This study aims to assess the burden of rubella infection within the existing measles case-based surveillance framework to provide evidence supporting advocacy for introducing the rubella-containing vaccine into the national immunization program. METHODS: This study conducted a retrospective descriptive analysis of rubella infection using measles case-based surveillance data from 2013 to 2023. Data were analyzed with descriptive statistics and logistic regression using Epi Info, version 7. RESULTS: During the study period, 17,987 suspected measles cases were reported, with 4944 serum samples collected. Of these, 2083 (42.1%) were positive for measles immunoglobulin M antibodies. Among 2861 samples that tested negative or indeterminate for measles, 678 (23.7%) tested positive for rubella immunoglobulin M antibodies. The study observed a significant increase in rubella positivity rates from 1.6% in 2014 to 34.4% in 2020. Logistic regression analysis showed that rubella infection was significantly more likely among children aged 5-9 years (odds ratio [OR] = 2.234; 95% confidence interval [CI]; 1.468-3.473, P < .001), 10-14 years (OR = 2.101; 95% CI, 1.570-4.428; P < .001), and 1-4 years (OR = 1.733; 95% CI, 1.149-2.687; P = .003), compared to children aged younger than 1 year (reference group). Rubella positivity was also slightly higher in urban settings than rural areas (OR = 1.139; 95% CI, 1.004-1.527; P = .034). Rubella cases demonstrated clear seasonality, with increased cases occurring from December and peaking in March. CONCLUSIONS: The study identified a high prevalence of rubella among young children, particularly those aged 1-9 years and in urban areas, highlighting the need for targeted vaccination strategies. These findings strongly support introducing the rubella vaccine into the national immunization program.