Evaluation of measles elimination strategies in Dongola, Sudan: a surveillance and immunization converge analysis, 2018–2021

Sudan began measles elimination activities in 2004, as measles remains one of the leading causes of the childhood mortality. This study aimed to evaluate the ongoing activities concerning measles elimination including immunization converges in routine and supplementary vaccination activities, and surveillance system. A retrospective descriptive study was conducted in Dongola locality in Northern state- Sudan from Jan 2018 to Dec 2021. A total of 10 surveillance sites were visited and interviews with 11 focal persons, 29 doctors, EPI head office and operation officers including surveillance officer. Data were collected using WHO- adapted structured questionnaires. The study found high measles immunization coverage in 2021 (MCV1: 99.9%, MCV2 80.6%. As for the Surveillance efforts, it found that 100% of suspected measles cases were thoroughly investigated within 48 h, and all reported cases had the required blood samples collected for further analysis. Laboratory confirmed measles cases that were reported between 2018 to 2021 of those who were not vaccinated was 90%, those who were vaccinated with one dose were 5%, and those who were vaccinated with two doses were 5%. Yet 10% focal persons lacked knowledge of measles case definitions. Measles elimination efforts in Dongola show strong first-dose coverage (99.9%) and effective surveillance, but challenges remain, including low second-dose uptake (80.6%), laboratory delays, and healthcare provider knowledge gaps. Strengthening MCV2 coverage, improving lab performance, training providers, and boosting community engagement are essential. Future research should explore factors affecting vaccine uptake and the long-term impact of improved immunization strategies.