Epidemiological Characteristics and Risk Factors of Severe Fever With Thrombocytopenia Syndrome in Yantai City, Shandong Province

Abstract

Background To better understand the epidemiological characteristics and risk factors associated with the incidence of severe fever with thrombocytopenia syndrome (SFTS) in Yantai City, Shandong Province, China. Methods The SFTS data from 2010 to 2019 were obtained from the National Notifiable Disease Reporting System, and visualization was performed using ArcGIS 10. A community-based, 1:2 matched case-control study was conducted to investigate the risk factors for SFTS in Yantai City. Standardized questionnaires were used to collect detailed information about the demographics and risk factors for SFTSV infection. Results A total of 968 laboratory-confirmed SFTS cases were reported, 155 (16.01%) of which were fatal. The SFTS epidemic curve revealed that most cases occurred from May to August, accounting for 77.27% of all studied cases. The SFTS cases were mainly distributed in Lai Zhou, Penglai, Zhaoyuan, Haiyang, and Qixia from 2010 to 2019 (accounting for 83.47% of all cases). No differences in demographics were observed between the cases and controls. In the multivariate analysis, presence of rats in the household (OR=2.89, 95%CI=1.94-4.30), bitten by the ticks one month before the onset of symptoms (odds ratio [OR]=15.97, 95% confidence interval [CI]=5.36-47.60), and presence of weeds and shrubs around the house (OR=1.70, 95%CI=1.12-2.60) were found to be the risk factors for SFTS. Conclusions Our results support the hypothesis that ticks are important vectors of the SFTS virus. Education on SFTS prevention and personal hygiene should be imparted in high-risk populations, especially among outdoor workers living in SFTS-endemic areas, while vector management should also be considered.

Spatiotemporal distribution and environmental influences of severe fever with thrombocytopenia syndrome in Shandong Province, China

“…However, there are also different views; for example, some scholars believe that the migration of ticks and the small animals that carry them may allow SFTSV to expand to more areas and thus lead to more human infections [ 38 , 39 ]. Similar to the findings of prior studies [ 13 , 16 , 40 , 41 ], SFTS cases were mainly recorded from April to October, which may be related to the dynamics of the ticks. Haemaphysalis longicornis and Dermacentor nuttalli are dominant tick species in Shandong Province, accounting for 75.3 and 24.7% of the collected ticks, respectively [ 33 , 42 ].…”

Time series models in prediction of severe fever with thrombocytopenia syndrome cases in Shandong province, China

“…The region of Shandong Province, where this study was conducted, has been identified as one of the areas with a high incidence of SFTS ( Huang et al., 2021 ; Liu et al., 2015 ). Previous studies have analyzed the risk factors associated with SFTS incidence and developed multivariate models in this region ( Hou et al., 2023 ; Jiang et al., 2022 ; Wang et al., 2022 ). However, to our knowledge, this is the first study to focus on building univariate models for predicting SFTS incidence, which is simpler and more practical.…”