Projected spatial distribution and geographic shifts of suitable habitats for two major plague vectors under climate and land-use change in Qinghai, China.

BACKGROUND: Climate change and land-use change may alter the suitable habitats of vector species. As two major plague vectors in Qinghai Province, Callopsylla dolabris (C. dolabris)and Oropsylla silantiewi (O. silantiewi) play important roles in plague transmission, and shifts in their suitable habitats may substantially increase the potential risk of plague spillover to humans. However, current plague prevention and control strategies primarily rely on historical epidemic distributions and lack forward-looking assessments of future risks. Therefore, predicting the distribution of plague vector suitable habitats under future scenarios and elucidating their spatial change patterns are essential for optimizing plague surveillance strategies and improving the allocation of prevention and control resources. METHODS: This study integrated plague vector occurrence records with 1 km-resolution bioclimatic variables, elevation, and land-use data. The maximum entropy (MaxEnt) model combined with GIS-based spatial analysis techniques was used to characterize the spatial distribution of suitable habitats for the two plague vectors under future climate scenarios and to elucidate their spatial change patterns. Finally, by spatially overlaying population data, priority surveillance areas within newly emerging suitable habitats of plague vectors were identified. RESULTS: This study found that, Under future scenarios, suitable habitats of both plague vectors showed overall expansion and spatial shifts toward northwestern regions and higher elevations. The two vectors exhibited distinct spatial patterns of priority surveillance areas within newly expanded habitats, with C. dolabris showing clustered distributions and O. silantiewi showing more dispersed patterns. CONCLUSION: This study characterized the spatial distribution patterns of suitable habitats for two major plague vectors in Qinghai Province, revealed their spatial dynamics, and identified priority surveillance areas within newly expanded suitable habitats. The findings provide scientific support for optimizing plague surveillance strategies and allocating prevention and control resources in Qinghai Province.