Vector biological monitoring and strategy to prevent and control severe fever with thrombocytopenia syndrome bunyavirus (SFTSV) in Daishan Country Zhoushan Islands 2011-2018 / 上海预防医学

ABSTRACT

Objective To study the severe fever with thrombocytopenia syndrome bunyavirus (SFTSV)-related vector biological monitoring in Daishan County, Zhoushan Island of Zhejiang Province, and to explore the prevention and control strategies. Methods The monitoring was conducted as follows:squirrel-cage method was used for rodents from 2012 to 2014;the Buqi method for free tick density in villages and towns with confirmed cases in Daishan County from 2015 to 2018;and body surface comb method for parasitic ticks.RT-PCR method was used to detect SFTSV in ticks and rat specimens.Epidemiological survey followed by extensive health education was conducted from 2011 to 2015.Comprehensive health prevention and control measures, such as precision health education and chemical elimination of vectors were taken from 2016 to 2018. Results A total of 327 rodents were captured, including 172 stinking shrews, accounting for 52.60%, and 92 yellow mice, accounting for 28.13%.The main species of ticks was Haematopsus longicortus, accounting for 94.20%.Among them, there were 135 parasitic ticks in three species:Haematopsus longicorum, S.scallopus, and T.nigra. There were 382 free ticks in 6 species, including Haematopsichum longicorum, Sickle fan tick, Hemophilus fannicus, Ixodes ovaliformis, Ixodes granulata, and Ixodes sinensis.From May to October in 2015, the density of field ticks was ≥50 per cloth flag.From May 2016 to 2018, after the elimination application of chemical agents for elimination, the density of ticks was ≤50 per cloth flag.All ticks and rodent specimens tested by RT-PCR were negative for SFTSV.Since precision education in 2016, the awareness rate of SFTS in rural areas has increased from 32.05% to 83.33%.Approximately 70 early warning notices for the epidemic situation were issued in advance.Since 2017, the number of SFTS has been declining year by year, and only 8 cases occurred in 2018. Conclusion In the field environment, chlorothalonil is the dominant mouse species and long horn blood ticks are the dominant ticks.The government leadership, cooperation among departments, technical service provided by professional organization, health education, reduction of tick density in residential environment, timely risk early warning notice, and other comprehensive prevention and control hand strategy all contribute to the achieved result of prevention and control.