Seroprevalence rates and transmission of plague (Yersinia pestis) in mammalian carnivores.

Exposure to plague (Yersinia pestis) by flea-bites or consumption of infected rodents is common in mammalian carnivores in North America. Most carnivore species exhibit seroprevalence rates ranging from 3% to 100% in areas where plague occurs. Seroprevalence is highest in mustelids, intermediate in ursids, felids, and canids, and lowest in procyonids, probably reflecting variation in exposure rates as a function of dietary habits. Although conventional wisdom suggests that carnivores may only be important in plague ecology as vectors of infective fleas, animal-to-human (zoonotic) transmission suggests that mammalian carnivores can act as infectious hosts. Furthermore, a review of clinical investigations reveals that plague can be harvested from canid and felid hosts, and suggests the possibility of plague transmission between carnivores. Further study of plague transmission by carnivores in both wild and laboratory conditions is needed to understand the possible role of carnivores as wildlife reservoirs of plague.