Polymerase chain reaction (PCR) identification of rodent blood meals confirms host sharing by flea vectors of plague.

Elucidating feeding relationships between hosts and parasites remains a significant challenge in studies of the ecology of infectious diseases, especially those involving small or cryptic vectors. Black-tailed prairie dogs (Cynomys ludovicianus) are a species of conservation importance in the North American Great Plains whose populations are extirpated by plague, a flea-vectored, bacterial disease. Using polymerase chain reaction (PCR) assays, we determined that fleas (Oropsylla hirsuta) associated with prairie dogs feed upon northern grasshopper mice (Onychomys leucogaster), a rodent that has been implicated in the transmission and maintenance of plague in prairie-dog colonies.

Evidence for the involvement of an alternate rodent host in the dynamics of introduced plague in prairie dogs.

1. The introduction of plague to North America is a significant threat to colonies of prairie dogs (Cynomys ludovicianus), a species of conservation concern in the Great Plains. Other small rodents are exposed to the causative agent, Yersinia pestis, during or after epizootics; yet, its effect on these rodents is not known, and their role in transmitting and maintaining plague in the absence of prairie dogs remains unclear.