Having an unmistakable effect on human history, particularly through the Middle Ages, evidence of the plague has surfaced in two counties in Arizona.  Testing fleas in the area, officials with both Navajo and Coconino counties have issued warnings about the presence of the disease.

Caused by the bacterium Yersinia pestis, the plague takes three main forms in humans: pneumonic, septicemic and bubonic.  While bubonic is the most widely known of the forms, each of them is quite serious in nature.  While there have been no reports of human contraction as of yet, health officials are getting ahead of the possibility by issuing public warnings.

“Navajo County Health Department is urging the public to take precautions to reduce their risk of exposure to this serious disease, which can be present in fleas, rodents, rabbits and predators that feed upon these animals,” the officials wrote. “The disease can be transmitted to humans and other animals by the bite of an infected flea or by direct contact with an infected animal.”

Today, the plague is relatively uncommon in humans with a median of three cases per year in the United States between 2001 and 2012.  In 2015, cases spiked, resulting in four deaths, with most of the infections taking place in the American West.

The plague, while scary in nature, is treatable with modern medicine but only if caught early enough.  It is spread quickly from fleas to pets or wildlife and then eventually to humans.  By biting prairie dogs, rabbits or household pets, the disease can then be transmitted to humans as demonstrated below by the U.S. Centers for Disease Control and Prevention.

plague-graphic-USCDCP
(U.S. Centers for Disease Control and Prevention)

When it comes to wildlife, ingesting the meat or handling an infected carcass of an animal with plague can also transmit the disease to humans.  While relatively rare in big game species, there have been instances where transmission to humans has come from large mammals.