Temperature- and host-driven model of Phlebotomus papatasi outbreak potential under climate change in Sudan

Cutaneous leishmaniasis (CL) is a major public health concern in Sudan, transmitted by Phlebotomus papatasi, whose survival and reproduction are influenced by temperature and host availability. Despite the known role of environmental drivers, mechanistic, spatially explicit models integrating vector eco-physiology and host accessibility are lacking. To address this, we developed a physiologically structured population model using a temperature-driven Metzler matrix to simulate stage-specific transitions, modulating fecundity by land cover–based host accessibility and scaling persistence with livestock-derived carrying capacity. The resulting suitability index was used to compute spatial outbreak probabilities under historical and projected climate scenarios (2050), validated against occurrence records and endemic foci. The model captured 77 % of endemic sites, reproduced ecological thresholds (with suitability near zero at 15 °C), and identified high-risk regions in southern and western Sudan. Scenario analysis revealed potential emergence in central regions, while extreme warming (SSP5–8.5) reduced suitability in thermally stressed zones. This mechanistic, trait-based framework provides a biologically grounded, spatially explicit tool to anticipate CL outbreak risk, supporting proactive health planning in fragile and conflict-affected settings.