Environmental Suitability of Anopheles Mosquito Species in the Maekel Region, Eritrea: Species Distribution Modeling Using Maximum Entropy

Introduction: Malaria, a significant global health challenge, is closely associated with Anopheles mosquitoes. The dependence of mosquito habitats on environmental conditions, coupled with the established link between malaria prevalence and habitat niches, highlights the dynamic interplay between mosquito ecology and environmental factors in malaria transmission. This study aims to determine the current and future environmental suitability of Anopheles mosquitoes in the Maekel region using species distribution modeling (SDM). Methodology: Species occurrence data, along with environmental and bioclimatic variables, were used to model habitat suitability using Maxent. Highly correlated variables, defined as those with a Pearson correlation coefficient exceeding 0.8, were excluded from the model. Future climate projections from the Coupled Model Intercomparison Project (CMIP-6) were used to project species distributions under two shared socioeconomic pathway scenarios: SSP370 and SSP585. Key environmental variables influencing species survival were identified through the jackknife test of variable importance. Model performance was evaluated via area under the curve (AUC) statistics. Results: A total of 94 samples were collected from 24 villages. The most prevalent species, Anopheles cinereus , was identified in 20 villages, followed by Anopheles demeilloni and Anopheles squamosus . Anopheles gambiae , the primary malaria vector in Eritrea and Africa, was identified at 5 sites in 4 villages. Maxent modeling indicated that large areas of the Maekel region are highly suitable for Anopheles species, with projected increases in suitability by 2030 and 2050 under both climate change scenarios. Conclusion: Anopheles mosquitoes are well established across significant portions of the Maekel region, and their distribution is projected to expand in the future. Comprehensive nationwide studies are necessary to map species distributions and bionomics, enabling the refinement of malaria control strategies in response to the rapid expansion of Anopheles mosquitoes driven by climate change.