LAUSR

Background Ethiopia has made a significant progress of malaria control. Currently, the country has adopted and is implementing the World Health Organization very ambitious, but achievable, malaria elimination plan through extensive efforts. The regular evaluation of its performance is vital for plausible improvement. Thus, the aim of this study was to determine the trends of malaria infection in Boricha district, Southern Ethiopia. Methods A retrospective study was conducted in all health facilities of the district. All malaria cases registered during 2010 to 2017 were reviewed to determine the trends of malaria morbidity. EpiData 3.1 was used for data entry and data were analysed using SPSS version 20.0. Results A total of 135,607 malaria suspects were diagnosed using microscopy and rapid diagnostic test over the last 8 years, of which 29,554 (21.8%) were confirmed positive cases. Plasmodium falciparum, Plasmodium vivax and mixed infections (both species) accounted for 56.3%, 38.4% and 5.2% of cases, respectively. Except in 2013 and 2014, Plasmodium falciparum was the dominant species over P. vivax . Of the total confirmed cases 51.6% were adults (≥ 15 years) followed by 24.5% of 5–14 years, and 23.9% of under 5 years. In general, malaria morbidity was significantly reduced over the last 8 years. The positivity rate declined from 54.6% to 5% during 2010 to 2017, and the case incidence rate per 1000 population at risk also declined from 18.9 to 2.2 during the same period. Malaria was reported in all months of the year, with peaks in November, followed by September and July. Malaria transmission has strong association with season (x 2  = 303.955, df = 22, p < 0.0001). Conclusion In general, a significant reduction of malaria morbidity was observed over the past 8 years. However, further investigation using advanced diagnostic tools is vital to determine the level of sub-microscopic infections to guide the elimination plan. In addition, eco-epidemiological analysis at fine-scale level is essential to devise area-specific interventions.