Environmental change increases the transmission risk of visceral leishmaniasis in central China around the Taihang mountains

Abstract

Background: Visceral leishmaniasis is a neglected life-threatening sandfly-borne disease, which brings a growing public health threat in Central China around the Taihang Mountains. However, the spatiotemporal dynamics of visceral leishmaniasis in the local community and the potential driving factors remain poorly understood. Methods: We analyzed the spatiotemporal patterns of new reported visceral leishmaniasis cases in the region from 2006 to 2023, and combined random forest modeling approach with environmental covariates to identify the main influencing factors related to transmission risk of the disease. Results: Our results show that there was a total number of 800 reported human visceral leishmaniasis cases, affecting 29 cities, and 113 counties across the region, exhibiting a geographic expansion of the disease during this period, especially in Shanxi province. Two high-risk clusters were identified in the study. Environmental change-related factors, including standardized precipitation deviation, forest cumulative change ratio, and normalized difference vegetation index (NDVI) cumulative change, played important roles in increasing the transmission risk of visceral leishmaniasis, with their relative contributions summing up to 66.17%. Conclusions: Our findings provide a better understanding of the spatiotemporal dynamics and driving factors of visceral leishmaniasis recurrence across Central China around the Taihang Mountains, which underscore prevention and control measures should be taken immediately to reduce the risk.