The principal source of infection were Marmota himalayana(72. 72%)and,Ovis aries(18. 18%)infected with causative a-gent of plague,while contacting with infected animals directly was the main route.

• 传染源主要是染疫喜马拉雅旱獭（Marmzotahimalayana），占72.；72%25，藏系绵羊（ovisaries），占18。 18%25；