Okechukwu Paul-Chima Ugwu, Chinyere Nneoma Ugwu, Godson Emeka Anyanwu, Mariam Basajja
Anopheles stephensi is an invasive urban malaria vector whose expansion in the Horn of Africa has raised concern because of its ability to exploit human-made water-holding habitats. In Kenya, molecular surveillance first confirmed the presence of An. stephensi in Marsabit and Turkana counties in 2022, and subsequent nationwide work documented spread into additional counties including Isiolo. Published Kenyan field data show larvae in dumped tires, plastic containers, water-storage tanks, concrete cisterns, spillover around community water points, and water pits at mining sites. Although no habitat-by-habitat productivity analysis has yet been published for Isiolo alone, evidence from Kenya and ecologically comparable semi-arid settings in eastern Ethiopia indicates that large domestic and construction-related water-storage habitats can dominate dry-season larval production in such environments. Based on this evidence synthesis, we argue that urban water-storage containers should be prioritized as initial surveillance targets for molecular surveillance of An. stephensi in Isiolo. Operational targets should include jerrycans, barrels or drums, cut or discarded tanks, rooftop and ground-level tanks, concrete cisterns, overflow points near communal water systems, and drawing on Ethiopian comparative evidence, construction-associated water reservoirs. Because larval habitats in Kenya frequently contain mixed mosquito assemblages and morphology can be challenging in newly invaded settings, ITS2- and cox1-based confirmation should be incorporated into surveillance workflows.