Anopheles stephensi bionomics and epidemiology in Ethiopia: A systematic review and meta-analysis with implications for urban malaria control
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Background
Anopheles stephensi , an invasive malaria vector originally endemic to South Asia, has rapidly expanded across East Africa. Its emerging malaria threats in urban Ethiopia threaten the elimination efforts, especially in areas once deemed low risk. A systematic review was conducted to synthesize the evidence regarding its bionomics and epidemiological impact, highlighting implications for urban malaria control strategies. This systematic review provides the first Ethiopia-specific quantitative evidence synthesis, addressing a vital knowledge gap necessary for guiding national malaria elimination programmes.
Methods
We conducted a PRISMA 2020-compliant systematic review and meta-analysis registered with PROSPERO (CRD420251176953). Searches of PubMed, Scopus, Web of Science, and regional repositories (2016–February 2026) identified studies reporting An. stephensi bionomics and epidemiological role in Ethiopia. Eligible studies required ≥50% quality score on JBI appraisal tools. Random-effects meta-analysis estimated pooled proportions of An. stephensi among total Anopheles, with subgroup analyses by geography, habitat, and behavioural traits. Publication bias was assessed using Egger’s and Begg’s tests.
Results
Eighteen studies (9 epidemiological, 11 bionomical) met inclusion criteria. The pooled proportion of An. stephensi was 0.51 (95% CI: 0.28–0.75) in epidemiological studies and 0.46 (95% CI: 0.26–0.66) in bionomics studies, with extreme heterogeneity (I² > 99%). Geographic analysis indicated significant variation: south-eastern Ethiopia showed a dominance of 0.73 (95% CI: 0.28–1.18) and eastern Ethiopia 0.57 (95% CI: 0.32–0.82), while central Ethiopia remained lower at 0.13 (95% CI: 0.12–0.14). These findings demonstrate genuine ecological differences rather than methodological objects, with substantial implications for region-specific vector management strategies. Extreme heterogeneity reflected genuine ecological variation across Ethiopia. No evidence of publication bias was detected.
Conclusion
An. stephensi has very rapidly emerged as a major malaria vector in Ethiopia, with pooled proportions increasing from <10% at first detection (2016) to 51–73% in recent surveys (2024–2025), suggesting ongoing vector displacement parallel to invasion patterns documented in Djibouti. Geographic stratification indicates an urgent need for region-specific urban vector management integrating larval source management, resistance monitoring, and community engagement, particularly in south-eastern Ethiopia, where near-complete vector replacement has occurred.
Author Summary
Malaria is usually thought of as a rural disease, but a new mosquito species called An. stephensi is changing that picture in Ethiopia. Originally found in South Asia, this mosquito has spread quickly across East Africa and is now common in Ethiopian towns and cities. We reviewed and combined results from published studies to understand how this species behaves and how much it contributes to malaria transmission. Our analysis shows that An. stephensi has become one of the dominant malaria vectors in several regions of Ethiopia, especially in the east and south-east, where it has almost replaced other mosquito species. This rapid change means that malaria risk is increasing in urban areas that were previously considered low risk. These findings highlight the urgent need for new control strategies that focus on city environments, such as managing breeding sites, monitoring insecticide resistance, and involving communities in prevention efforts. By understanding how An. stephensi is spreading and adapting, we can better protect urban populations and support Ethiopia’s malaria elimination goals.
