Study On The Distribution And Pathogen Spectrum Of Rhipicephalus Sanguineus Based On Multiple Data

BackgroundRhipicephalus sanguineus(R.sanguineus),commonly known as the brown dog tick,is a three-host tick characterized by a long activity cycle and strong adaptability.R.sanguineus can infest on domestic animals and wild animals,and has also been reported to infest on humans in several countries.R.sanguineus is a main vector of various human-associated and animal-associated pathogens,such as Ehrlichia canis,Rickettsia rickettsii and Babesia vogeli.R.sanguineus not only caused skin damage,anemia,and reduced production of meat and milk of animals,more seriously,lead to disease or death due to pathogens.Climate change and rapid urbanization have promoted close contact between ticks and human which increased the risk of emerging tick-borne diseases.Therefore,it is of great veterinary and public health significance to monitor and study of R.sanguineus.ObjectivesThe present study aims to comprehensively describe the global distribution of R.sanguineus,indicate the species of hosts in different countries,clarify the epidemic characteristics of microorganisms carried by R.sanguineus,and explore whether there were regional differences of R.sanguineus-associated microorganisms.To provide the scientific basis for the prevention and control of R.sanguineus and related tick-borne pathogens.MethodsThe data collected in this study were collected from the following five parts:1)literature review;2)Global Biodiversity Information Facility(GBIF);3)GenBank;4)field survey and 5)reference book(Fauna Sinica Arachnida Ixodid).All data were collected up to September 1,2022.ArcGIS software was used to map the distribution of the microorganisms carried by the R.sanguineus.Meta-analysis was done with meta package to investigate the prevalence of the R.sanguineus-associated microorganisms.Phylogenetic trees were constructed using the maximum likelihood approach(ML).Results1.The distribution of R.sanguineus had been recorded in 99 countries around the world,mainly in regions between latitude 50° N and 40° S with annual mean temperature higher than 10℃.This species was not only found in the interior of six continents,but also on multiple islands in the Atlantic,Indian and Pacific Oceans.Moreover,Asia and North America had the highest number of records,with 823 and 650 records,respectively.2.R.sanguineus were collected from 98 species of hosts,including domestic animals,wild animals,and humans.Dogs was the main host,which had been reported in 89 countries.Moreover,humans bitten by R.sanguineus had been reported in 16 countries.Among all countries,China,Portugal and Sri Lanka reported the highest number of hosts,with 26,21 and 21 species.3.A total of 182 microorganisms had been detected in the R.sanguineus,including 60 species that can infect humans and 32 species that can infect animals.The positive rate of 90%of the microorganisms was 0-25%.Of the six continents,the most microorganisms were detected in Asia and Europe,with 103 and 84 species.Rickettsia was the most diverse genus detected in R.sanguineus,with 26 species,involving 315 detection sites.4.Crimean-Congo hemorrhagic fever orthonairovirus(CCHFV)carried by R.sanguineus was clustered at the national level,and the sequences obtained in each country formed different clusters.In contrast,most of the other microorganisms clustered in species,and the sequences obtained from different countries clustered into a branch.Conclusions1.R.sanguineus is one of the most widely distributed tick species around the world,which can be found on the other six continents except Antarctica.Surveillance systems should be established timely in countries where R.sanguineus is distributed to reduce the public health threat.2.R.sanguineus has a strong host adaptability,and can infest on many domestic and wild animals.It is necessary to strengthen the prevention and control of ticks in domestic animals,and outdoor crowd should also keep a safe distance from wild animals.3.The composition and wide distribution of microorganisms carried by R.sanguineus may be related to the large number of hosts.In addition,the epidemiological distribution characteristics of diseases caused by pathogens carried by R.sanguineus are consistent with distribution of R.sanguineus.It is suggested that the surveillance and study of the R.sanguineus and its pathogens should be strengthened.4.Most of the microorganisms carried by R.sanguineus are highly identity in different regions,but CCHFV shows national cluster,which may be related to the fact that viruses are more prone to mutation than bacteria and protozoa.