Elimination of endemic measles and rubella transmission in Oman.

Objectives: The main objective of the study is to describe the five lines of evidence of measles and rubella elimination in Oman.

Methods: A descriptive record review of the national surveillance database of fever and rash illnesses (measles and rubella surveillance) to demonstrate elimination status.

Results: A total of 532 and 73 cases of measles and rubella cases were reported during 2000-2022, respectively. Of the reported measles cases during 2000-2022, 106 were sporadic cases and 36 outbreaks (426 cases) were reported. The size of the outbreaks was largely small and the largest and the longest outbreak was in 2016-2017 involving the Dhofar-South Sharqiyah governorates with 90 cases due to genotype B3, which lasted for 32 weeks. Of the reported rubella cases during 2000-2022; all 73 were sporadic cases with no outbreaks. The vaccination coverage of Measles Mumps Rubella 2 is high (>98.0%) at the national and sub-national levels since 2008, thus maintaining the high population immunity. The absence of endemic genotype was proven through genetic sequencing of all the reported cases and outbreaks of measles and rubella. The high-performance indicators showed quality surveillance system.

Conclusions: Oman fulfills the criteria for measles and rubella elimination. All the five lines of evidence were verified and Oman was certified to have eliminated measles and rubella in 2019. After 3 years of post-elimination, Oman has continued to maintain its elimination status successfully. High population immunity and quality surveillance resulted in sustaining the elimination during the post-elimination period.