In a follow-up to the report last week of a human case of bubonic plague in a La Plata County resident, San Juan Basin Health (SJBH) officials say they identified plague positive fleas from a prairie dog burrow in western La Plata County during a subsequent investigation.

Prairie dog burrow
Prairie dogs
Image/Singer Ron, U.S. Fish and Wildlife Service

This has prompted officials to warn the public to take precautions to protect themselves from the infected fleas.

Plague is found in animals throughout the world, most commonly rats but other rodents like ground squirrels, prairie dogs, chipmunks, rabbits and voles. Fleas typically serve as the vector of plague. Human cases have been linked to the domestic cats and dogs that brought infected fleas into the house.

People can also get infected through direct contact with an infected animal, through inhalation and in the case of pneumonic plague, person to person.

Yersinia pestis, the bacterial agent of plague,  is treatable with antibiotics if started early enough. There are three forms of human plague; bubonic, septicemic and pneumonic.

SJBH says bubonic plague, the form of plague the La Plata County patient had,  is the most common form of plague in humans. Symptoms begin two to six days after the bite of an infected flea or contact with an infected rodent or cat.  Symptoms typically include sudden onset of fever, headache, chills, weakness, and one or more swollen, tender, and painful lymph nodes (called buboes).

If you have had a possible exposure to infected rodents or fleas and are experiencing these symptoms, consult a physician as soon as possible. Colorado has identified 64 cases of human plague, nine (14%) of which were fatal, since 1957.  For more infectious disease news and information, visit and “like” the Infectious Disease News Facebook page.