Malaria outbreak investigation in Siraro District, Oromia Region, Ethiopia,2021

Background In Ethiopia, malaria is highly seasonal in many communities with epidemic-prone transmission patterns and serious public health emergencies that have a major impact on health and the economy. This investigation aimed to assess malaria outbreaks, identify their risk factors and provide appropriate control & prevention measures of the infection in Siraro district,west Arsi,Oromia,Ethiopia. Methods A unmatched case-control study with a 1:1 case-to-control ratio was conducted in the Siraro District from 16 June 2021 to 03 August 2021. Seventy-four randomly selected cases and controls participated in this study. We reviewed the previous five year’s malaria data to establish a threshold level. Both descriptive and analytical statistical procedures were performed. The data were entered using Epi-Info version 7.2.4.0 software and analyzed by using SPSS version 25. Multivariable logistic regression analysis was conducted to identify independent factors associated with malaria infection. Results plasmodium Falciparum accounts for about 81.4%. Age group ≥ 5 years were the most affected with an attack rate (AR) of 2.04/1000. Multivariate analysis revealed the place of stay during night adjusted Odds Ratio (AOR) 5.62, 95% CI = 1.016–31.069, a person with malaria in the house with AOR 15.74,95% CI = 3.029–81.865, presence of stagnant water near to house AOR of 25.60, 95% CI = 4.696-139.649, availability of plants with temporary water pools in the compound an AOR of 90.94,95% CI = 9.019-917.012 and a person who does not hear about malaria prevention on insecticide-treated bed nets utilization adjusted Odds Ratios ( AOR) of 0.14,95% CI: 0.076, 1.061 were the main associated risk factors for the occurrence of the outbreak. Conclusions The main risk factors for the outbreak were people with malaria in the house, stagnant water, and plants with temporary water pools and it was positive for Anopheles larvae. We recommended identifying potential vector breeding sites and environmental management through community participation and redistribution of the ITN before malaria season and ITNs utilization gaps through health education.