Flores-Perez, N.; Kulkarni, P.; Uhart, M.; Pandit, P.

Background: The drylands vesper mouse (Calomys musculinus) is the principal host for Junin mammarenavirus (JUNV), which causes Argentine Hemorrhagic Fever (AHF) in humans. In our study, we aimed to assess the probable range of C. musculinus and to identify hotspots for potential disease transmission to humans under current and future climate change scenarios. Methodology/Principal Findings: We used tree-based machine learning (ML) classification algorithms to generate and project C. musculinus habitat suitability under two climate change scenarios for the years 2050 and 2070 using bioclimatic and landscape related predictors. Evaluation of the models showed high accuracy, with AUCROC ranging from 86.81-89.84%. The analysis of the importance and influence of different variables indicated that the rodent prefers warm temperatures, moderate annual precipitation, low precipitation variability, and low pasture coverage. While a severe climate change scenario (Representative Concentration Pathway 8.5) suggests a reduction in suitable areas for JUNV reservoir and a decrease in hotspots for potential disease transmission, an intermediate scenario (Representative Concentration Pathway 4.5) displays expansion in areas for C. musculinus distribution alongside increased potential hotspot zones. Conclusions/Significance: While acknowledging the complexity of ecological systems and the limitations of the species distribution models, our findings offer a framework for developing preventive measures and conducting ecological studies in regions prone to C. musculinus expansion and hotspots for potential disease transmission driven by climate change. Preventive interventions will need to be adapted to target C. musculinus changing spatial dynamics.