Research On Global Geographic Distribution And Associated Pathogens Of Ixodes Persulcatus

BackgroundIn recent years,the number of emerging and re-emerging tick-borne diseases worldwide has been increasing yearly,attracting widespread attention and concern from various countries.As an important vector,ticks can cause a variety of natural focus diseases,posing a great danger to the health of human and livestock.Ixodes persulcatus(I.persulcatus)is one of the most important hard ticks in the Northern Hemisphere,parasitizing a variety of hosts and transmitting diseases such as Lyme disease and tick-borne encephalitis,posing an incalculable public health threat.However,previous studies focused on a single country or region,and there is a lack of comprehensive studies on I.persulcatus,its hosts and the pathogens it carries,and many countries do not yet have comprehensive tick surveillance systems.The global disease risk of the tick species and carried pathogens is not fully understood.Therefore,it is necessary to conduct systematic and in-depth research on related issues to provide a basis for scientific prevention and control of tick-and tick-borne diseases.Objectives1.To understand the global geographic distribution of I.persulcatus,the species and distribubtion of hosts,identifying the countries or regions that need to be focused on.2.To develop a high-resolution global distribution prediction model and explore the factors influencing the distribution of I.persulcatus.3.To understand the prevalence and geographic distribution of pathogens carried by I.persulcatus.4.To understand the genetic diversity of main Borrelia burgdorferi sensu lato carried by I.persulcatus.MethodsIn this study,a comprehensive multi-source database of I.persulcatus was established based on field survey,literature review,reference book and relevant website.ArcGIS software was used to map the geographic distribution of I.persulcatus and its associated pathogens.The species and countries of distribution of parasitic hosts of this tick species were described.Meta-analysis was applied to estimate the positive rate and 95%confidence interval of I.persulcatus associated pathogens.A maximum entropy ecological niche model was used to predict the global potential distribution of I.persulcatus and to assess the influence of environmental factors on its distribution.The genetic diversity of Borrelia burgdorferi sensu lato carried by I.persulcatus was analyzed using the maximum likelihood method.Results1.I.persulcatus was distributed in 14 countries between 21°-66°latitude in the Northern Hemisphere,spanning the Eurasian continent,mainly in western Russia,northeastern China,and countries around the Baltic Sea.2.I.persulcatus could parasitize 46 species of host animals belonging to 22 families and 36 genera,including humans,rodents,birds,etc.And there have been reports in eight countries across Eurasia.3.I.persulcatus could carry at least 52 well-classified microorganisms,such as Anaplasma,Babesia,Rickettsia,tick-borne encephalitis virus,of which 33 were human pathogens and 6 were animal pathogens.4.Predictive model showed that the global potential distribution of I.persulcatus was mainly influenced by factors such as mean temperature of coldest quarter,precipitation of warmest quarter,temperature seasonality,and had high fitness in northeastern China,western Russia,eastern Europe.5.Borrelia burgdorferi sensu lato carried by I persulcatus isolated from Russia were more closely related to Borrelia burgdorferi carried by a variety of ticks and rodents,and were more closely related to China and South Korea.Conclusions1.I.persulcatusis were concentrated in 14 countries across Eurasia.The potential hazards posed by I.persulcatus should be given high priority in countries and regions where it is widely distributed.2.I.persulcatus has a strong adaptability to its hosts and can parasitize a wide range of hosts,including humans,various domesticated animals,and wild animals.Therefore,management of vectors and host should be strengthened,and targeted measures should be taken for the public to realize self-protection.3.I.persulcatus can carry lots of human and animal pathogenic pathogens,posing a serious health risk to humans and animals.Therefore surveillance of tick-borne diseases should be strengthened to achieve early detection,diagnosis and treatment.4.Based on the prediction results of ecological niche model,the potential distribution I.persulcatus were concentrated in the Northern Hemisphere,mainly influenced by temperature.Relevant research should be strengthened to adopt more targeted tick-borne disease prevention and control measures.5.Borrelia burgdorferi sensu lato may be transmitted between different countries or regions through import and export trade,so the inspection and quarantine of imported and exported goods should be strengthened to protect the development of domestic livestock and poultry breeding industry and public health safety.