Epidemic characteristics of severe fever with thrombocytopenia syndrome and surveillance of infection in ticks and animals in Shengzhou,Zhejiang Province,China,2016-2023
Objective To analyze the epidemic characteristics of severe fever with thrombocytopenia syndrome (SFTS) and monitor the infection of host animal,vectors,and human populations in Shengzhou,Zhejiang Province,China,2016-2023,so as to provide a scientific basis for the development of prevention and control strategies.Methods The population,temporal,and spatial distributions,epidemiological history,clinical characteristics,and hospital visit of SFTS cases were analyzed using the descriptive epidemiological method.Chi-square test and Mann-Whitney U test were used to analyze differences between groups.SFTS cases from 2016 to 2023 were obtained from the China Disease Prevention and Control Information System and epidemiological investigations of the cases.Serum samples of healthy people and host animals were collected for detection of Dabie bandavirus antibody.On-host and free-living ticks were monitored using animal body surface examination and the drag/flag sampling method.Dabie bandavirus in host animals and ticks was detected by real-time fluorescence quantitative PCR.Results From 2016 to 2023,27 cases of SFTS were reported,of which 17 cases in 2023,including 10 (37.04％) males and 17 (62.96％) females,with an average annual incidence of 0.56/100000 and a fatality rate of 22.22％.Moreover,23 (85.19％) cases were local farmers engaged in tea picking and agriculture.The age of onset ranged from 51 to 94 years,with a median of 68 years.The incidence showed significant seasonality,mainly from April to August.Circular distribution analysis showed that the peak of the disease occurred between May 11 and August 29.Locally transmitted cases were reported in 9 out of 15 townships (streets).All cases had a history of field activities 2 weeks before onset.The main clinical manifestations were fever (96.30％),fatigue (81.48％),loss of appetite (59.26％),leukopenia (96.30％),and thrombocytopenia (88.89％).In 2023,the median time from onset of symptoms to hospital visit was 3.0 days,and the median time from visit to diagnosis was 2.0 days.One case was diagnosed after 4 visits,and 10 (58.82％) cases were diagnosed after 1 visit.The positive rate of Dabie bandavirus antibody in the serum of healthy population was 2.50％.A total of 35 free-living ticks were captured in Shengzhou from 2016 to 2023,with a mean density of 0.23 ticks/(flag·100 m).Additionally,417 parasitic ticks were captured,with a mean on-host tick index of 4.53.Of host animals,sheep,cattle,and dogs were positive for Dabie bandavirus antibody in serum,and the positive rates were 27.69％,11.11％,and 6.67％,respectively.Ticks and host animals were negative for Dabie bandavirus nucleic acids.Conclusions The incidence of SFTS in Shengzhou increased rapidly in 2023.There may be a natural epidemic focus of SFTS in Shengzhou.The epidemic showed significant seasonality,and elderly farmers were at high risk.It is necessary to strengthen the publicity and education regarding SFTS,implement environmental remediation and vectors control,and improve the diagnosis and treatment levels of primary medical institutions.
Severe fever with thrombocytopenia syndrome (SFTS)Epidemic characteristicsHost animalVector
万方数据
维普
