Abstract
<title>Abstract</title> <p> <bold>Introduction</bold> Malaria continues to pose a significant public health challenge in Ethiopia, especially in areas with a favorable environment for transmission. Timely detection, notification, and response are essential to reduce outbreak impact. This study assessed the timeliness of detection, notification, and response using the 7-1-7 framework and investigated the magnitude and risk factors of a malaria outbreak in Loma District, Southwest Ethiopia Region, 2024. <bold>Methods</bold> A descriptive cross-sectional and unmatched case–control study was conducted in Loma district from epidemiological weeks 37–52, 2024. Malaria line lists were used to describe the outbreak by person, place, and time, while 186 participants (62 cases and 124 controls) were enrolled to identify risk factors. Data were collected using Kobo Toolbox and a semi-structured 7-1-7 assessment tool. Logistic regression analysis was performed using SPSS to identify factors associated with malaria infection at a 95% confidence interval. <bold>Result</bold> Detection, notification, and response were delayed across all 7-1-7 metrics. A total of 24,574 confirmed malaria cases were reported with slide positivity rate of 73% and attack rate of 249 per 1,000 population. <italic>Plasmodium falciparum</italic> accounted for 81% of cases. Addis-Bodari kebele reported the highest attack rate (796 per 1,000 population). Also, living near water-holding bodies (AOR = 3.26; 95% CI: 1.43–7.41), staying outdoors at night (AOR = 3.12; 95% CI: 1.32–7.33), knowledge on malaria transmission (AOR = 0.22; 95% CI: 0.09–0.52) and proper use of insecticide-treated nets (AOR = 0.25; 95% CI: 0.08–0.77) were associated with malaria infection in the area. <bold>Conclusion</bold> Malaria outbreak in Loma District was characterized by poor 7-1-7 timeliness, high transmission, and environmental risk factors. Strengthening surveillance timeliness, vector control interventions, proper ITN utilization, and community awareness is critical to improve malaria control and prevent future outbreaks. </p>