Investigation And Analysis Of Blood Parasites And Zoonotic Pathogens Carried By Ticks In Hunan Cattle Farm

The cattle industry in Hunan Province is developing in a large-scale direction,and the parasitic phenomenon of ticks on cattle herds still exists.The spread and prevalence of many tick-borne diseases have a potential negative impact on public health safety and the healthy development of the cattle industry.To understand the carriage of Babesia bigemina,Theileria orientalis,Anaplasma marginale,Borrelia burgdorferi(BB),Severe Fever with Thrombocytopenia Syndrome Virus(SFTSV),Anaplasma phagocytophilum(Ap)and Ehrlichia by ticks on cattle farms in Hunan Province.From August to November 2020,1649 Rhipicephalus microplus ticks were collected from 37 cattle farms in 8 municipalities and prefectures of Hunan Province.1649 ticks were mixed by site,and 172 mixed samples were obtained for every 10 ticks mixed as a sample,and if the part with less than 10 ticks was mixed as a sample with the actual number.Blood parasites were detected by establishing a multiplex fluorescent PCR method and zoonoses were detected using commercial kits.The results of blood parasite detection showed that among 172 mixed samples in 37 farms,22 field sites were positive for Babesia bigemina,with a field positive rate of 59.46%,43 mixed samples were positive,with a mixed sample positive rate of 25.00%;31 field sites were positive for Theileria orientalis,with a field positive rate of 87.78%,150 mixed samples were positive,with a mixed sample positive rate of 87.21%.26 field sites were positive in the Anaplasma marginale,with a field positive rate of 70.27%,145 mixed samples were positive,and the mixed positive rate was 84.30%.According to the regional distribution in Hunan Province,the positive rates of Babesia bigemina ranged from 16.24% to 77.27%;the positive rates of Theileria orientalis ranged from 20.00% to 100%;and the positive rates of Anaplasma marginale ranged from 63.64% to 100%.The peak period of pathogen carriage by Rhipicephalus microplus ticks is mostly in August and September,and there is a mixed carriage of multiple pathogens.The detection results of zoonotic agents showed that among 172 mixed samples in 37 farms,no BB and SFTSV were detected;20 field sites of Ap were positive,with a field positive rate of 54.45%,60 mixed samples were positive,with a mixed sample positive rate of 34.88%;9 field sites of Ehrlichia were positive,with a field positive rate of 24.32%,12 mixed samples were positive,with a mixed sample positive rate of 6.98%.According to the distribution in Hunan Province,the positive rates of Ap and Ehrlichia were 11.97% ～ 100%and 5.98% ～ 13.64%,respectively.Conclusion: The carriage rate of Rhipicephalus microplus ticks collected from cattle farms in Hunan Province to Babesia bigemina,Theileria orientalis and Anaplasma marginale is high,and transmission of these pathogens is very likely.No BB and SFTSV were detected in the samples collected this time.However,the carriage rate of Ap is high,and there may be natural foci,which require prolonged surveillance of this pathogen.The carriage rate of Ehrlichia by Rhipicephalus microplus ticks is generally low,and further research and investigation are needed.