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Pronunciation: zen'op-sil'a

Definition: The rat flea; a flea genus parasitic on the rat and involved in the transmission of bubonic plague. The species Xenopsylla cheopis serves as a potent vector of Yersinia pestis, largely because its gut becomes “blocked” by a mass of Y. pestis cells that prevents the flea from feeding normally, so that it is inclined to attack humans and other hosts; it has served as an important source of infection in epidemics, for example in India. Xenopsylla astia and Xenopsylla braziliensis are also efficient vectors of plague. It is an important source of infection in regions of the world where large numbers of people live in poverty.

[xeno- + G. psylla, flea]

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© Copyright 2018 Wolters Kluwer. All Rights Reserved. Review Date: Sep 19, 2016.