The causative bacterium of plague, Yersinia pestis, has been detected in fleas in Picture Canyon, Arizona. Deaths of prairie dogs in this region alerted officials to the possibility of the disease.
Prairie dogs are especially vulnerable to this bacterium as they live in social burrows which may be infested with rodents that carry the fleas bearing the disease causing bacteria. Once the host rodent dies, the fleas seek out new hosts to feed off as they are sanguinivorous. It has been noted that even a single infected member of a prairie dog colony may lead to the death of as many as 90% of the members of the colony.
Human cases have been known to develop from close contact with cats that have preyed on infected rodents, and adequate advisory is being issued, especially to campers and hikers in the region, about the risks of plague. In addition, the prairie dog burrows at the affected place, Picture Canyon, are being sprayed with insecticide to kill the fleas that may host the plague bacillus.