Assessment of influential factors and risk area prediction of scrub typhus in Gannan region, China, based on ecological niche modelling and geographical detector

Abstract

This study sought to define the potential infection risk zone of scrub typhus in Gannan and investigate the factors that contribute to this risk zone. Based on the distribution data of scrub typhus cases and environmental factors in Gannan from 2015–2021, a maximum entropy ecological niche modelling was employed to forecast potential risk areas in the region. The influence of each environmental factor on the risk was quantified using a geographical detector. The maximum entropy model's prediction remained robust, with an average area under the curve value of 0.852. The key predictor variables for scrub typhus occurrence were identified as land cover type, population density, and slope. In Gannan, the high-risk areas for scrub typhus were predominantly located in the central and southern regions, with Longnan city having the highest percentage of high-risk area at 22.92 %, followed by Xinfeng county at 14.01 %. The results of the geographical detector indicated that the environmental factors influencing risk levels primarily consisted of min temperature of coldest month, mean annual sunshine duration, and mean annual relative humidity. All interactions measured strengths of 0.999 between wind speed and relative humidity, wind speed and sunshine duration, and sunshine duration and relative humidity. The findings of this study outline the risk factors influencing the incidence of scrub typhus and pinpoint potential risk areas for the disease. This information will serve as a foundation for Gannan's relevant authorities to devise more efficient surveillance and control measures.