Insights from a measles outbreak root cause analysis in Ethiopia - 2024.

Introduction: Ethiopia has been implementing measles elimination strategies since 2003, including periodic supplemental immunisation activities every 2-3 years, and the introduction of a second dose measles vaccine in 2018. At national level, the coverage for first and second dose measles vaccine is 61% and 53% respectively. In the past decade, populations displacements and service disruptions due to natural and man-made disasters, exacerbated by the impact of the COVID-19 pandemic on the sub-optimally functioning immunisation system, have contributed to multiple measles outbreaks in the country. Methods: between July and August of 2024, a total of 44 woredas conducted a measles outbreak response vaccination campaign. Among these, 11 woredas were selected purposively to implement an outbreak root cause analysis exercise. Analysis of data and document reviews were done at woreda and health facility levels, along with interview of immunization program officers at different administrative levels, and interviews of care givers of confirmed measles cases. Results: in 2024, a total of 4664 confirmed measles cases and 24 deaths were reported to the national level from the 11 woredas. Despite reported high administrative vaccine coverage at the woreda level, only 56% of the measles cases had received at least one dose of measles vaccine, as seen during household visits. More than half (55%) of the 11 woredas do not have any facility that offers daily vaccination services, due to staff shortage (36%), concerns of vaccine wastage (36%), and lack of operational funding (18%). Twelve (44%) out of the 27 health posts and one-third (8 of 24) of the health centers do not give measles vaccines in every vaccination session. Cancellations of vaccination sessions were reported from 24 health centers and 27 health posts in 4 woredas due to various reasons including staff shortage, vaccine stockout, lack of means of transportation for field trips and electric power interruption. Non vaccination due to a combination of these multiple factors was identified as the root cause of the measles outbreaks. Conclusion: there are cross-cutting systemic factors that contributed to the measles outbreaks in various woredas, alongside contextual factors which differ from one health facility to another and between woredas. It is important that these findings are used to develop tailored efforts to strengthen routine immunisation services within the service catchment areas. Root cause analysis should be implemented as part of every outbreak investigation and response efforts.