However, plague was not transmitted when healthy young Marmota baibacina were bitten by the infected fleas, indicating that human flea grey marmot strain played a minor role in the spread of plague.

• 用大数量感染的人蚤灰旱獭株(分别为265只、102只)对健康幼獭叮咬,未出现鼠疫的传播,表明人蚤灰旱獭株感染蚤的鼠疫媒介能力甚低。