Malaria Outbreak Investigation in Nensebo District, West Arsi Zone, Southeast Ethiopia: A case-control study

Background: Malaria-related morbidity and mortality are 94% concentrated in Africa. Ethiopia is one of ten African countries affected by malaria, with 60% the population living malaria-risk areas. Recently, seasonal outbreaks have been reported all regions, including previously malaria-free Nationally, Nensebo district west Arsi zone classified as having very low transmission. During 21st WHO week 2021, Melka Denbi kebele an unusually high number malaria cases to this district. The purpose study was look into magnitude outbreak factors that contributed it. Methods: A descriptive followed unmatched case-control on 86 172 controls who were chosen at random. Malaria those confirmed positive rapid diagnostic test (RDT) line-listed a health facility, while lived nearby negative RDT. At p-value 0.05 95% confidence interval, logistic regression used identify contracting factors.Results: With mean age 22 (12.31SD), overall attack rate 20.2/1000. Plasmodium vivax (PV) 105 (52.8%) most common. Staying out night (AOR=3.94; 95%CI: 2.18-7.37) stagnant water/intermittent river within 1 km vicinity risk factors. Screened houses protective (AOR=0.49; 0.27-0.89), knowledge transmission (AOR=0.51; 0.28-0.93) prevention control methods (AOR=0.50; 0.27-0.93).Conclusion: illness caused primarily PV species known for their relapsing characteristics. Risk included water near homes sleeping outside night. screening centers increased public awareness reduce disease. Our recommendations regular environmental monitoring, behavioral change communication, ensuring radical cure, further research detailed entomological survey climate variables.