Spatio-temporal distribution and environmental influences of severe fever with thrombocytopenia syndrome in Shandong Province, China

Abstract

Abstract Background Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease discovered in China in 2009. The purpose of this study was to describe the spatiao-temporal distribution of SFTS and to identify its environmental influencing factors and potential high-risk areas in Shandong province of China. Methods Data of SFTS incidence from 2010 to 2021 were collected. Spatio-temporal scanning statistic was used to identify the time and area of SFTS clustering. Maximum entropy (MaxEnt) model was used to analyze environmental influences and predict high-risk areas. Results From 2010 to 2021, a total of 5705 cases of SFTS were reported in Shandong. The number of SFTS cases increased year by year, with a peak incidence from April to October each year. Spatio-temporal scanning statistic showed the existence of one most likely cluster and two secondary likely clusters in Shandong. The most likely cluster was in the eastern region, from May to October in 2021. The first secondary cluster was in the central region, from May to October in 2021. The second secondary cluster was in the southeastern region, from May to September in 2020. MaxEnt model showed that mean annual wind speed, NDVI, cattle density and annual cumulative precipitation were the key factors influencing the occurrence of SFTS. The predicted risk map showed that the area of high-prevalence, was 28,120 km2, accounting for 18.05% of the total area of the province. Conclusions The spatio-temporal distribution of SFTS was heterogeneous and influenced by multidimensional environmental factors. This should be considered as a basis for delineating SFTS risk areas and developing SFTS prevention and control measures.