Peer-reviewed article

Epidemiological Measles Outbreaks Investigation in Nogob Zone, Somali Region, Eastern Ethiopia: Trends and Insights from 2019 To 2024.

Ahmed Bihi Abdi, Seid Muhumed Abdilaahi, Mohammed Adem Maalin, Ahmed Mohammed Ibrahim · 19 Mar 2026

Abstract

BACKGROUND: Measles remains a major vaccine-preventable cause of childhood morbidity and mortality, particularly in low-coverage settings. Measles remains endemic in Ethiopia, and Somali Regional State (SRS) experiences high incidence rates despite vaccination efforts. OBJECTIVES: This study aimed to investigate measles outbreaks and provide critical insights into the epidemiological trends. METHODS: A retrospective descriptive study was conducted using surveillance data from Nogob Zone. All reported measles cases (confirmed, epidemiologically linked, and clinically compatible; n = 2,214) were included through inclusion of complete line lists. WHO case definitions were applied. Data were analyzed using Microsoft Excel, Epi-Info, and ArcGIS 10.8 to generate descriptive statistics, epidemiological curves, attack rates, and spatial maps. RESULTS: From 2019 to 2024, a total of 2,214 measles cases and 58 deaths were reported (case fatality rate: 2.6%), exceeding national rates. Children aged 5–14 years were most affected (42%), followed by those aged 15 years and older (33%). Geographically, Duhun and Garbo woredas had the highest attack rates (18 and 17 per 1,000 population, respectively). The outbreak peaked in 2023, with a decline thereafter. CONCLUSIONS: The study shows that Nogob Zone has faced a substantial measles burden, reporting 2,214 cases and a 2.6% case fatality rate between 2019 and 2024. The notably high attack rates observed in Garbo and Duhun woredas, along with a major outbreak surge in early 2023, point to persistent gaps in vaccination coverage and systemic barriers. Strengthening routine immunization, improving surveillance, and implementing targeted catch-up campaigns are recommended to prevent future outbreaks.