Objective: Ticks act as vectors,transmitting pathogens to wildlife,domestic animals,or humans through their bites.The investigation of tick-borne pathogens shows that Xinjiang is one of the regions with the most tick-borne diseases.In recent years,a number of novel viruses have been identified in ticks by macro virus detection,but their ecology and relationship to humans remains unclear.In this study,we investigated the ecology of Bole tick virus 1(BLTV-1)in xinjiang border area and detected and analyzed newly infected tick bite patients.Methods: From April 2020 to August 2021,free ticks and parasitic ticks of cattle and sheep were collected in Xinjiang for identification of tick species by morphological and molecular biological methods,and molecular epidemiological background investigation of Tick species and region for BlTV-1 was conducted.To understand the major tick species and regional distribution of newly discovered BlTV-1.(2)Wild gerbils from the dominant tick species in Xinjiang were collected at the same time,and the spleen bl TV-1 was detected by Nested RT-PCR to investigate the positive rate of BLTV-1 in gerbils under natural conditions.A genetic evolutionary tree was constructed to analyze the genetic evolutionary relationship between BLTV-1 in wild animals and BlTV-1 in dominant tick species.(3)The "transovarial transmission" of BlTV-1 was studied by RT-PCR and genetic evolution analysis of haemaphysalis gurtu.(4)The tick-bite patients in Xinjiang were collected,and the infection of tick-borne Bunyavirus,including Tacheng tick virus 1(Tc TV-1),Tacheng tick virus 2(Tc TV-2)and BLTV-1,was investigated by RT-PCR,so as to preliminarly understand the situation,clinical characteristics and treatment measures of human infection with tick-borne Bunyavirus.The genetic evolutionary tree was constructed to analyze the genetic evolutionary relationship between human bunyavirus sequences and dominant tick species and wild animals.Results:(1)Results of tick species identification: a total of 350 ticks were detected in six regions of Xinjiang,and they belonged to three genera,namely Hyalomma asiaticum(Hyalomma Koch),Dermacentor marginatus(Dermacentor Koch)and Rhipicephalus turanicus(Rhipicephalus Koch).(2)Pathogen investigation results: BlTV-1 was detected in Hyalomma asiaticum in Alashankou,Xinhu and Bachu,with positive rates of 23.9%(16/67),26.1%(11/42)and 64%(32/50),respectively.In Alashankou,2of the 24(8.3%)cattle parasites Dermacentor marginatus were detected as positive.No BlTV-1 was detected in 92 Dermacentor marginatus from sheep,cattle and horse parasitized in Tacheng area and 36 Dermacentor marginatus from Wenqian county.The positive rate of BlTV-1 was 2.56%(1/39)in Rhipicephalus turanicus from Sangong Village near Shihezi.The average positive rate of Hyalomma asiaticum was 37.5%,followed by 8.3% of Dermacentor marginatus and 2.56% of Rhipicephalus turanicus.(3)Results of the transovarial transmission of BlTV-1 : The positive rates of BlTV-1 nucleic acid were34.5%(58/168),36.9%(61/168)and 42.8%(72/168),respectively.(4)Results of the investigation on the pathogen of wild host: The spleen of 85 wild gerbils from Alashankou and 83 wild gerbils from Xinhu were detected,and the positive rate of BlTV-1 nucleic acid was 16.5%(14/85)and 4.8%(4/83),respectively.(5)Detection results of newly buniavirus in hospitalized tick bite patients: One tick bite patient was positive for BlTV-1 and a tick bite patient with fever and meningitis co-infected with Rickettsia raoultii and Tacheng tick virus 1 from blood samples collected from 23 patients.Conclusion:(1)Hyalomma asiaticum,Dermacentor marginatus and Rhipicephalus turanicus all carried the new bunyavirus BlTV-1 in xinjiang,and confirmed that BlTV-1 could be transovarial transmission in Hyalomma asiaticum.Therefore,Hyalomma asiaticum may be the main host vector of BLTV-1.(2)Nucleic acid BlTV-1 was detected in the spleen of wild gerbils,extending the natural reservoir of the virus.(3)The nucleic acid of BlTV-1 was detected in the blood of patients with tick bite for the first time,suggesting that BlTV-1 is a potential pathogen of the tick bite fever patients.A case of severe acute meningitis co-infected by Rickettsia rickettsiae and Tc TV-1 was also found.(4)BlTV-1 belongs to the Genus Buniavirus.Through epidemiological investigation,it was found that BlTV-1 had the characteristic of "zoonosis" and could transmit the virus to humans and wild animals through tick bites. |