high as 5--10% \[[@CR5]\]. AE prevalence is mainly constrained to the northern hemisphere. The areas with the high incidence are mainly Alaska, northern and central Europe, Central Asia, Siberia, China and Japan \[[@CR6], [@CR7]\].

The epidemic of hydatidosis is serious in western and northern China \[[@CR8]--[@CR10]\]. The Tibet Autonomous Region (TAR) is located in the south-western part of the Qinghai-Tibet Plateau, which has an average elevation of over 4000 m. The region has seven prefectures and a total of 74 counties under its jurisdiction, with a grassland area of 650 000 ha, accounting for 56.72% of the total land area in the region. Farming and grazing yaks, sheep and other livestock are the primary livelihood. It is a heavy epidemic areas with echinococcosis in TAR. B-ultrasonography for self-selected study subjects in Dingqingin humans {#Sec4}
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### Sampling {#Sec5}

The Tibet region has a total of 74 counties in seven prefectures that include 692 townships and 5260 villages. The region has a total population of 3 million. After consulting senior statistician, the sample number is about 2--3% of the total population in TAR. In accordance with the main mode of production of the local residents, all villages were classified into Pastoral area (animal husbandry only), semi-Pastoral and semi-Farm area (animal husbandry and farming both), Farm area (farming only), urban areas (live in urban). A stratified and proportionate sampling method was adopted, and the survey was conducted from August to November 2016. A total of 380 villages were selected in Tibet based on the population of the county: we selected 16 villages, eight villages,