Investigation On The Animal Parasitic Ticks And Tick-borne Zoonotic Disease Carrying Situation In Western Of Liaoning Province

ObjectiveThe survey investigate the grazing cattle,sheep ang dogs(domestic dogs and shepherd dogs)parasitic ticks and tick-borne zoonotic disease carrying situation in western of Liaoning province,so as to provide for the relevant departments of the province with scientific basis of the tick and tick-borne zoonoses prevention and control measures.MethodsBased on the geography characteristics of western Liaoning province,Linghai,Yixian,Taihe district,Xingcheng,Suizhong were chosen as the survey points and grazing cattle sheep and dogs(domestic dogs and shepherd dogs)as mining ticks objects.Ticks were collected randomly once a month in the popular tick season(May to September),ensuring that each survey point the number of ticks collected from cattle and sheep are more than 100,while dog ticks over 30 and 1646 new fresh ticks were collected from the five survey points.Traditional morphological identification method was used to identify the species of ticks and statistical intensity of infection and advantage ticks were determined.Ticks were preserved at-80? after classified by different animals and tick species,after which the tick-borne pathogen detection of zoonotic diseases was carried out.According to the domestic epidemic of tick-borne zoonoses and hazard situation,7 kinds of important tick-borne zoonoses: tick-borne encephalitis(TBE),severe fever with thrombocytopenia syndrome(SFTS),Crimean Congo hemorrhagic fever(CCHF),spotted fever(SF),Q fever(Q fever),babesiosis(Babesiosis),Lyme disease(Lyme disease)were selected as the research objects,and method of polymerase chain reaction(PCR)was adopted to test the tick-borne zoonoses carrying cases.In view of the detected the tick-borne zoonoses(positive samples)part of the gene sequencing,with the comparison of tick-borne zoonoses gene sequences similarity by Blast software,according to the analysis results for further validation,animal parasitic ticks carrying species of the tick-borne zoonoses was finally confirmed in western of Liaoning Province.Results1.Animals parasitic ticks infected survey resultsAfter identification,the 1646 animal parasitic ticks surveyed in western of Liaoning Province(Ling Hai,Yi county,Taihe district,Xingcheng,Suizhong)belonged to 4 genera and 5 species: Dermacentor silvarum,Haemaphysalis longicornis,Haemaphysalis bispinosa,Ixodes persulcatus,Hyalomma detritum.In which Haemaphysalis longicornis accounted for 34.7%(571/1646),Dermacentor silvarum accounted for 26.2%(431/1646),Ixodes persulcatus accounted for 16.0%(264/1646),Haemaphysalis bispinosa accounted for 14.8%(243/1646),Hyalomma detritum accounted for 8.3%(137/1646).After data analysis,it is concluded that Haemaphysalis longicornis and Dermacentor silvarum are advantage tick species in cattle,sheep and dogs of western Liaoning Province.2.PCR results of seven kinds of tick-borne zoonosesSpotted fever rickettsia and Q fever rickettsia are carried by the ticks in western of Liaoning Province.90 group tick samples,tick-borne encephalitis,severe fever with thrombocytopenia syndrome,Crimean Congo hemorrhagic fever,babesiosis,Lyme disease was not detected.In Suizhong county two kinds of ticks in two groups of samples(the 18 th group Haemaphysalis longicornis,the 39 th group Dermacentor silvarum)were detected two individual plants spotted fever rickettsia,In yixian county a kind of ticks in a group of samples(the 4th group Haemaphysalis longicornis)was detected one individual plant Q fever rickettsia.3.Partial gene sequencing results of two kinds of tick-borne zoonosesTwo individual plants spotted fever rickettsia detection were named respectively SZX-BD18 and SZX-BD39.An individual plant Q fever rickettsia detected was named YX-Q4.Sequence analysis showed that two individual plants spotted fever rickettsia(SZX-BD18 and SZX-BD39)are exactly the same gene sequence and the size of its gene sequence is 640 bp,while the gene sequence size of Q fever rickettsia is 260 bp.They are consistent with the expected fragment size.4.Partial gene similarity analysisDetected two individual plants spotted fever rickettsia(SZX-BD18,SZX-BD39)of part of the gene sequence with the gene library FUJ98(AF169629),Hl R / D91(KC888951),QHD-1(HQ651815),QHD-2(HQ651816),SHHMU-5(JX841232),SHHMU-3(JX841230)6 individual plants spotted fever rickettsia of the gene sequence similarity is 99%,Simultaneously with the HL-93(AF179364)similarity is 95%,with the JL-02(AY093696)similarity is 93%.Comparative analysis showed that in western of Liaoning Province detected SZX-BD9 and SZX-BD13 indeed are spotted fever rickettsia.Detected a individual plant Q fever rickettsia(YX-Q4)with the gene library Namibia(CP007555),Cbuk Q154(CP001020),Yunnan(EU000273),TW-1(KR697576),IE5(DQ379976)5 ndividual plants Q fever rickettsia part of the gene sequence similarity is 100%,with the selected primers IS111a(M80806)genetic similarity is 99%.Comparative analysis showed that in the western of Liaoning province detected YX-Q4 indeed is Q fever rickettsia.Conclusions1.Through the investigation of animal parasitic ticks from grazing cattle,sheep and dogs infected in the west of Liaoning province,it was found that the ticks belonged to four genera one family,the genus which are respectively Dermacentor silvarum,Haemaphysalis longicornis,Haemaphysalis bispinosa,Ixodes persulcatus,Hyalomma detritum,Haemaphysalis longicornis and Dermacentor silvarum are advantage tick species.2.Through seven kinds of tick-borne zoonoses-carrying survey,rickettsia spotted fever and Q fever rickettsia are found in animal parasitic ticks in western Liaoning Province.Spotted fever rickettsias are detected from Suizhong County,Q fever rickettsia is detected from Yixian.Tick-borne encephalitis severe fever with thrombocytopenia syndrome,Crimean Congo hemorrhagic fever,babesiosis,Lyme disease are not detected.3.Research indicates that animal parasitic ticks in vivo cniarrying rickettsia spotted fever and Q fever rickettsia two kinds of tick-borne zoonoses in western of Liaoning Province,the relevant departments should pay close attention to it,at the same time of strengthening prevention and controling of animal parasitic ticks work,also want to strengthen the crowd tick-borne zoonoses propaganda work and intervention.