Measles Outbreak Investigation in Garda Marta District, Southwestern Ethiopia, 2022: Community-Based Case-Control Study

BACKGROUND: A measles outbreak can occur in the presence of an increased number of unvaccinated children; however, the vaccine was available many decades ago, and it is the foremost cause of child mortality, claiming 568 lives (mostly children) worldwide each day. The investigation was aimed at assessing the magnitude and identifying contributing factors for the measles outbreak in the Garda Marta District of Gamo Zone, Southwestern Ethiopia. METHODS: From January 20 to February 10, 2022, a descriptive and unmatched case–control study was used to describe the measles outbreak and identify the associated risk factors for measles infection. The descriptive analysis employed all 140 cases from the line list, while the case–control study used 51 cases and 102 controls to investigate factors associated with measles infection. Epi-data version 4.6.0.6 was used to code and enter data, which was then exported to SPSS version 27 for analysis. A standardized questionnaire was used to collect data. To declare statistical significance for the association, multivariable logistic regression with an adjusted odds ratio (AOR) and 95% CI was used. RESULTS: From a total of 140 measles cases reported from October 12, 2021, to March 09, 2022, 75 (54%) were females. Marta Laddo kebele was most affected (104 cases). Being unvaccinated (AOR: 2.84, 95% CI: 1.10–7.32), having a travel history (AOR: 4.24, 95% CI: 1.61–11.15), having a contact history (AOR: 6.34, 95% CI: 2.35–17.40), being unaware of the mode of transmission (AOR: 2.68, 95% CI: 1.16–6.37), and having moderate acute malnutrition (AOR: 4.44, 95% CI: 1.74–11.31) were factors significantly associated with the measles outbreak. CONCLUSION: Being unvaccinated, travel history to measles outbreak area, contact history, knowledge of caretakers/mothers on the mode of transmission, and acute malnutrition were associated with the measles outbreak in the district. Therefore, strengthening routine measles immunization, mounting vaccination awareness and nutritional screening are recommended.