Plasticity of blood meal origin of Anopheles mosquitoes in Ethiopia: A systematic review

Abstract Background The efficacy of vector control tools depends on the behaviors of vector species. Many studies have sought to determine the blood meal origin of Anopheles mosquitoes in different settings of Ethiopia. This systematic review aims to generate the overall and species-specific source of blood meal of Anopheles mosquitoes in Ethiopia. Method A comprehensive search was conducted between March 11 and April 2, 2024, to locate studies that met predetermined selection criteria. After exhaustive screening, evaluation and critical appraisal of the selected studies, data were extracted using a pre-prepared template in Excel. Data were analyzed using STATA-14 software to produce a descriptive statistical summary of the overall and species-specific blood meal sources of Anopheles mosquitoes in Ethiopia. The study was conducted based on preferred reporting items for systematic reviews and meta-analysis guidelines. The protocol of this study was registered on international prospective register of systematic reviews, registration no. CRD42024515725. Result Of the 2,431 studies located, 27 met the inclusion criteria. In a total of 215 data points, 18,771 Anopheles mosquitoes that belonged to 23 species or species complex were tested for blood meal source. The dominant blood meal sources were bovine, 36.0% (n = 6,758) and human, 29.4% (n = 5,520). Anopheles arabiensis accounted for 67.9% (n = 12,741) followed by An. pharoensis, An. demeilloni and An. stephensi with 10.0%, 5.6% and 4.4% of the tested anophelines, respectively. Overall, there is no difference in mean proportion of An. arabiensis detected with domestic animals’ blood, 33.4% (95% CI, 32.4–34.4%), when compared with human blood, 31.8% (95% CI, 30.9–32.8%). However, higher proportion of outdoor collected An. arabiensis were found to feed on bovine, 47.9 (95% CI, 35.3, 60.6) when compared to human, 12.9 (95% CI, 0.8, 24.9, P < 0.01). The foraging ratio, which accounts for host availability, was high for bovine (FR = 0.7) when compared to human (FR = 0.2) for An. arabiensis indicating preferential feeding on bovine hosts. This host preference was supported by the host preference index (human: bovine = 0.4). Conclusion Bovine and human hosts were the common sources of blood meal for Anopheles mosquitoes. When considering host availability into account, An. arabiensis showed a preferential feeding on bovine/cattle. Targeting domestic animals, bovines and ovine with endectocides could supplement the current vector control interventions.