Objective:To investigate the epidemic characteristics of severe fever with thrombocytopenia syndrome (SFTS) in Tiantai County Zhejiang Province, and provide a scientific basis for prevention and control of SFTS.Methods:The case data of SFTS in Tiantai County from 2014 to 2024 were collected through the Chinese Disease Control and Prevention Information System, and descriptive epidemic method was employed to analyze its epidemic and clinical characteristics.Results:From 2014 to 2024, a total of 114 SFTS cases were reported in Tiantai County, with an average annual incidence rate of 2.21/100 000. The peak incidence occurred in 2021 (3.40/100 000, 16 cases). Nine cases died, with a mortality rate of 7.89% (9/114). The male-to-female ratio was 1.00∶0.97 (58∶56). The high-risk population was middle-aged and elderly people aged over 50 years old, accounting for 91.23% (104/114). The occupation was mainly farmers, accounting for 92.98% (106/114). The incidence of SFTS had obvious seasonality, with a peak from April to September, accounting for 83.33% (95/114). The average onset date was calculated to be June 25th, and the peak period was from April 19th to August 31st. The distribution of cases was mainly in Tantou Town (34 cases), Shiliang Town (23 cases), Yongxi Township (17 cases), and Pingqiao Town (12 cases), accounting for 75.44% (86/114). From 2014 to 2024, the affected areas had gradually expanded from 1 township/subdistrict to 13 townships/subdistricts, showed a phenomenon of migration from east to west. Among the 114 patients with SFTS, the initial symptom was fever. The proportion of neuropsychiatric symptoms, atrial fibrillation and heart failure in the death group was significantly higher than those in the survival group (χ 2 = 19.24, 16.44, 23.90, P < 0.001). Conclusion:From 2014 to 2024, the incidence of SFTS in Tiantai County fluctuates with obvious seasonal and regional migration characteristics.

Objective:To investigate the epidemic characteristics of severe fever with thrombocytopenia syndrome (SFTS) in Tiantai County Zhejiang Province, and provide a scientific basis for prevention and control of SFTS.Methods:The case data of SFTS in Tiantai County from 2014 to 2024 were collected through the Chinese Disease Control and Prevention Information System, and descriptive epidemic method was employed to analyze its epidemic and clinical characteristics.Results:From 2014 to 2024, a total of 114 SFTS cases were reported in Tiantai County, with an average annual incidence rate of 2.21/100 000. The peak incidence occurred in 2021 (3.40/100 000, 16 cases). Nine cases died, with a mortality rate of 7.89% (9/114). The male-to-female ratio was 1.00∶0.97 (58∶56). The high-risk population was middle-aged and elderly people aged over 50 years old, accounting for 91.23% (104/114). The occupation was mainly farmers, accounting for 92.98% (106/114). The incidence of SFTS had obvious seasonality, with a peak from April to September, accounting for 83.33% (95/114). The average onset date was calculated to be June 25th, and the peak period was from April 19th to August 31st. The distribution of cases was mainly in Tantou Town (34 cases), Shiliang Town (23 cases), Yongxi Township (17 cases), and Pingqiao Town (12 cases), accounting for 75.44% (86/114). From 2014 to 2024, the affected areas had gradually expanded from 1 township/subdistrict to 13 townships/subdistricts, showed a phenomenon of migration from east to west. Among the 114 patients with SFTS, the initial symptom was fever. The proportion of neuropsychiatric symptoms, atrial fibrillation and heart failure in the death group was significantly higher than those in the survival group (χ 2 = 19.24, 16.44, 23.90, P < 0.001). Conclusion:From 2014 to 2024, the incidence of SFTS in Tiantai County fluctuates with obvious seasonal and regional migration characteristics.

Objective: To investigate the prevalence of soil-borne nematode infections among rural residents in Tiantai County, Zhejiang Province, so as to provide insights into improving the control strategy. Methods: According to the Zhejiang Provincial Surveillance Programme on Soil-borne Nematodiasis and Clonorchiasis, 5 administrative villages were randomly selected in Tiantai County according to geographical locations on April, 2021, and all permanent residents at ages of 3 years and older were sampled from each village using a cluster sampling method. Subjects' gender, age, occupation, education level and deworming were collected. Subjects' stool samples were collected, and soil-borne nematode eggs were detected using the modified Kato-Katz technique, and larval culture was performed using a filter-paper culture method among hookworm egg positives for identification of hookworm species. In addition, the intensity of infection was evaluated using hookworm eggs per gram stool sample. Results: A total of 1 013 residents participated in the survey, including 495 men (48.86%) and 518 women (51.14%), and there were 502 participants at ages of 51 to 70 years (49.56%), 874 farmers (86.28%) and 436 subjects with an education level of primary school (43.04%). However, no subjects received deworming. The prevalence of hookworm infections was 3.85% among the study subjects, and only Necator americanus was identified. There were 31 cases with mild infections (79.49%), 5 cases with moderate infections (12.82%) and 3 cases with severe infections (7.69%), and all infections occurred in farmers. The prevalence of hookworm infections was 3.84% among men and 3.86% among women. No hookworm infection was detected among residents at ages of <41 years, and the prevalence of hookworm infections appeared a tendency towards a rise with age among residents at ages of 51 years and older (χ2trend=24.091, P<0.001), while the prevalence of hookworm infections appeared a tendency towards a decline with educational levels among residents (χ2trend=19.534, P<0.001). The greatest prevalence of hookworm infections was found in Qianyang Village (10.95%). Conclusions Hookworm disease is the predominant type of soil-borne nematodiasis in Tiantai County, and the middle-aged and elderly farmers with a low education level are high-risk populations for soil-borne nematodiasis control.