Composition, blood meal sources, and entomological inoculation rates of Anopheles mosquitoes in an urban setting, central Ethiopia

Abstract Background Despite ongoing reports of malaria from health facilities in central Ethiopia, entomological evidence on local vectors remains scarce. This study investigated Anopheles species composition, host preferences, and entomological inoculation rates in this urban setting. Methods A repeated cross-sectional and longitudinal entomological study was conducted in six districts (woredas), each of which had access to one of the three health centers (Akaki, Gelan, and Serti). Adult mosquitoes were collected from the houses of individuals with microscopically confirmed malaria, who served as the index cases, as well as from nearby animal shelters using CDC-LT and PKA. DNA of anophelines was used for species identification, blood meal source analysis, and detection of P. falciparum and P. vivax infections. Results Of 302 Anopheles collected, seven species were identified, including An. christyi (50.0%), An. arabiensis (21.5%), An. amharicus (7.6%), An. cinereus (5.0%), An. garnhami (1.3%), An. stephensi (1.3%), and An. rhodesiensis (0.7%). Two of these species, An. amharicus and An. stephensi, were recorded for the first time in the area. Analysis of abdominal contents of the 192 blood-fed females revealed that bovine blood was the most common (87.0%), followed by goat (34.9%) and human blood (25.5%). All four vector species (An. arabiensis, An. amharicus, An. stephensi, An. christyi) showed strong zoophilic (mostly feeding on cattle), though human blood and mixed human–bovine feeds were also detected in each of these species. P. falciparum sporozoites were detected in An. arabiensis, confirming its role in local transmission. Conclusion Seven Anopheles species were identified, of which Anopheles christyi was the most abundant species, followed by An. arabiensis. The presence of An. amharicus and invasive An. stephensi, combined with zoophilic yet opportunistic feeding behavior and P. falciparum-infected An. arabiensis, highlights local variations in the importance of these vectors and ongoing endemic transmission in this urban Ethiopian setting.