Factors Associated With Severe Fever With Thrombocytopenia Syndrome in Endemic Areas of China.

Xiaolin Jiang,Yiguan Wang,Mingxiao Yao,Xiaomei Zhang,Shaowei Sang,Bo Pang,Xueying Tian

doi:10.3389/fpubh.2022.844220

Abstract

ObjectiveTo explore the influence of climatic, environmental and socioeconomic factors on SFTS occurrence in Shandong Province, China.MethodsWe used generalized additive model to estimate the association between SFTS cases and climatic factors, environmental factors and socioeconomic factors, including annual average temperature, precipitation, land cover, normalized difference vegetation index, altitude, population density, meat production, milk production, and gross domestic product (GDP).ResultsThere were a total of 4,830 cases reported in 100 (70.9%) counties and districts in Shandong Province from 2010 to 2020. The results showed that the annual average temperature, precipitation, forest and grassland coverage rate, altitude and meat production (square root transform) had a reversed “V” relationship with SFTS occurrence, with the inflection points around 12.5–13.0°C in temperature, around 650 mm in precipitation, around 0.3 in forest and grassland coverage rate, around 300 m in altitude, and around 200–300 tons in meat production (square root transform), respectively. SFTS occurrence had a “V” relationship with milk production (square root transform) and GDP (square root transform), with the inflection points around 100–200 tons in milk production (square root transform), and around 150,000–200,000 yuan in GDP (square root transform), respectively.ConclusionsClimatic, environmental, and socioeconomic factors contributed to the heterogeneous distribution of SFTS in Shandong Province, and the influence of these factors on SFTS occurrence was nonlinear.

Highlights

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease, which was firstly reported in rural areas of Hubei Province and Henan Province, China in 2009 [1]
We used generalized additive model (GAM) to investigate the relationships between SFTS risk and the annual average temperature, precipitation, meat production, milk production, gross domestic product (GDP), forest and grassland coverage rate, normalized difference vegetation index (NDVI), and population
The models showed that SFTS occurrence was associated with annual average temperature, precipitation, meat production, milk production, GDP, forest and grassland coverage rate, and altitude (Figures 2,3)

Summary

Introduction

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease, which was firstly reported in rural areas of Hubei Province and Henan Province, China in 2009 [1]. After the identification of SFTSV, SFTS cases have been subsequently reported in Japan [2], Korea [3], and Vietnam [4]. SFTS has been listed as a notifiable disease in China since 2010. The number of SFTS cases have been continuously growing with an expansion of geographical distribution over the past decade in China. There were 11 provinces reporting SFTS cases in China in 2012 [7], but the number increased to 23 in 2016 [8] and 25 in 2018 [9]

Methods

Results

Discussion

Conclusion