Human flea Pulex Irritans grey marmot (Marmota baibacina) strain was experimentally infected with virulent Y. pestis 883, with infection rates of 58% for female and 51% for male fleas.

• 用鼠疫菌强毒株883号实现了对人蚤灰旱獭株的鼠疫苗感染,其感染率,雌性为58%25,雄性为51%25。