Echinococcosis, also known as hydatid disease, is caused by the metacestode stage of the species cluster Echinococcus granulosus sensu lato (E. granulosus s.l.). It is almost widespread worldwide, especially in countries and regions dominated by animal husbandry. It is a major parasitic disease that seriously endangers human health, public health safety, environmental safety, and the development of animal husbandry production in western China. In this study, the mitochondrial cox1 gene was used to analyze the genetic diversity and haplotype of bovine and sheep echinococcal cysts isolated in Tibet. Echinococcus granulosus sensu stricto (E. granulosus s.s., G1, G3) was still the dominant species in the infected samples of yak and sheep in some parts of Tibet. Through haplotype analysis, Hap_1 was deemed the dominant haplotype, 14 of the 20 haplotypes were similar to the reference sequence previously published in Genbank, and the rest of the 6 haplotypes were found for the first time. Through Tajima's D value, neutral test Fu's Fs analysis, and haplotype network map, it can be concluded that Echinococcus population expansion has occurred in Xigaze, Tibet. This study provides basic data for understanding the genetic characteristics, epidemiology, and control of echinococcosis in this area.

Background: Objective The study on the infection of hydatid disease in yaks in China provides the general epidemiological information of hydatid disease infection in yaks, which is of great value for the formulation of prevention and control strategies for hydatid disease. Method The database of yak hydatid disease infection rate was established by WPS Excel (version 11.1.0.11045-release). The provincial boundaries are vectorized by ArcGIS10.8 software, and the national and provincial boundaries and center vector maps are obtained. Taking the total number of yaks in different regions of China and the infection rate of hydatid disease of yaks in recent 40 years as attribute data, the data were matched with the basic map, and the spatial distribution map was drawn. Finally, spatial autocorrelation analysis, spatial clustering analysis, clustering and outlier analysis were used to analyze the spatial distribution of hydatid disease infection rate in county yaks in China. Results: Except for Yunnan Province, yaks were infected with hydatid disease in the other five provinces and autonomous regions. The infection rate of hydatid disease in yaks in the five provinces has shown a downward trend in the past 40 years. The species of Echinococcus granulosus and Echinococcus multilocularis infected by yaks in five provinces were Echinococcus granulosus and Echinococcus multilocularis. There was no Echinococcus multilocularis infection in yaks in Xinjiang. The results of spatial distribution of yak hydatid disease infection in counties of China showed that there were yak hydatid disease infection in 65 counties of five provinces in China. Most of the counties with high infection rate are concentrated at the junction of eastern, western and southeastern Qinghai province, and the average infection rate of hydatid disease in yak is more than 60%. However, the average infection rate of hydatid disease in yaks in western Xinjiang Autonomous region, Tianzhu County in Gansu Province and northeastern Qinghai Province is less than 10%. Conclusions: This is the first time based on ArcGIS to study the infection of hydatid disease in yaks in recent 40 years in China. The advantage is obvious and the spatial distribution is clear immediately.