- A flea genus commonly found on rodents. N. fasciatus, the northern rat flea, is a species that infrequently transmits the plague bacillus to humans. [noso- + G. psylla, flea]
* * *Nos·o·psyl·lus .näs-ə-'sil-əs n a genus of fleas that includes the northern rat flea (N. fasciatus)
* * *n.a genus of fleas. The common rat flea of temperate regions, N. fasciatus, will, in the absence of rats, bite humans and may therefore transmit plague or murine typhus from an infected rat population. The rat flea is also an intermediate host for the larval stage of two tapeworms, Hymenolepis and H. nana.
* * *Noso·psyl·lus (nos″o-silґəs) [noso- + Gr. psylla flea] a genus of fleas. N. fasciaґtus, the rat flea of North America and Europe, is a vector of murine typhus and probably of plague.
Medical dictionary. 2011.