The persistent threat of malaria in Bishoftu Town: twelve-year trends and their implications for Addis Ababa.

Bishoftu town, located about 40 km from the largely malaria-free Addis Ababa, remains malaria-endemic. Factors that possibly heighten exposure risk include abundant water bodies, increased visitors during events such as the Irreechaa festival, climate change, and changing land-use around the town. Frequent travel and strong interconnections raise concerns about spillover to Addis Ababa via infected people or mosquitoes. The potential spread of the invasive urban vector Anopheles stephensi is an additional concern, although there is currently little evidence of its introduction in Bishoftu. Future surges in transmission could be facilitated by infrastructure projects most particularly the construction of a major new airport in Bishoftu that will increase visitor traffic. Analysis of 252,610 blood films from the Bishoftu Town Health Office (January 2011 - December 2022) revealed 5,696(2.3%) malaria cases, with Plasmodium vivax at 63.8% and P. falciparum at 31.0%. The highest incidence (804 cases) occurred in 2017, with individuals > 14 constituting 66.3% of cases. Findings indicate persistent malaria with a fluctuating trend, highlighting the need for aggressive surveillance and targeted control measures to combat malaria in Bishoftu and prevent its spread to Addis, considering demographic shifts, increased mobility, and the development of recreational water pools associated with development projects.