Vector control improves survival of three species of prairie dogs (Cynomys) in areas considered enzootic for plague

Vector-Borne and Zoonotic Diseases
By: , and 

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Abstract

Plague causes periodic epizootics that decimate populations of prairie dogs (PDs) (Cynomys), but the means by which the causative bacterium (Yersinia pestis) persists between epizootics are poorly understood. Plague epizootics in PDs might arise as the result of introductions of Y. pestis from sources outside PD colonies. However, it remains possible that plague persists in PDs during interepizootic periods and is transmitted at low rates among highly susceptible individuals within and between their colonies. If this is true, application of vector control to reduce flea numbers might reduce mortality among PDs. To test whether vector control enhances PD survival in the absence of obvious plague epizootics, we reduced the numbers of fleas (vectors for Y. pestis) 96–98% (1 month posttreatment) on 15 areas involving three species of PDs (Cynomys leucurusCynomys parvidens in Utah, and Cynomys ludovicianus in Montana) during 2000–2004 using deltamethrin dust delivered into burrows as a pulicide. Even during years without epizootic plague, PD survival rates at dusted sites were 31–45% higher for adults and 2–34% higher for juveniles compared to survival rates at nondusted sites. Y. pestis was cultured from 49 of the 851 flea pools tested (6882 total fleas) and antibodies against Y. pestis were identified in serum samples from 40 of 2631 PDs. Although other explanations are possible, including transmission of other potentially fatal pathogens by fleas, ticks, or other ectoparasites, our results suggest that plague might be maintained indefinitely in PD populations in the absence of free epizootics and widespread mortality among these animals. If PDs and their fleas support enzootic cycles of plague transmission, there would be important implications for the conservation of these animals and other species.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Vector control improves survival of three species of prairie dogs (Cynomys) in areas considered enzootic for plague
Series title Vector-Borne and Zoonotic Diseases
DOI 10.1089/vbz.2009.0049
Volume 10
Issue 1
Year Published 2010
Language English
Publisher Mary Ann Liebert, Inc.
Contributing office(s) Fort Collins Science Center
Description 10 p.
First page 17
Last page 26
Online Only (Y/N) N
Additional Online Files (Y/N) N