Colorado has been hit especially hard with zoonotic infections this year. First we saw a slew of tularemia cases and now for the second time today, health officials from the state of Colorado are reporting a human case of plague, caused by the bacterium, Yersinia pestis.

boulderThe latest case, the fourth in the state this year, is reported from Boulder County.

Boulder County Public Health has confirmed that a Boulder resident tested positive for plague after finding a dead chipmunk on their property. The individual went to the doctor after experiencing fever, chills, muscle pain, weakness, loss of appetite, and confusion a few days after finding the chipmunk. The person received antibiotic treatment and is now recovering at home.

This is the first person to test positive for the disease in Boulder County since 1993. Three other Colorado residents have become ill from the disease so far this year; two of them did not survive.

“In Boulder County, we so often see plague in prairie dogs,” said Jamie Feld, Communicable Disease Control program epidemiologist. “This is a good reminder that plague-infected fleas are also found on many other wild rodents.”

Plague occurs naturally in Colorado and is an infectious disease that spreads when infected fleas bite wild rodents or other small mammals such as rock squirrels, wood rats, ground squirrels, chipmunks, mice, voles, prairie dogs, and rabbits. Wild carnivores can also become infected by eating other infected animals.

Plague can spread to humans when infected fleas from pets or wild rodents bite them, or when they touch dead or dying animals infected with the disease.

When rodents die from plague, the hungry fleas seek other sources of blood. People and animals visiting places where rodents have recently died from plague are at risk of being infected from flea bites.

“Because plague is most commonly transmitted by fleas, taking steps to avoid exposure to fleas will help to prevent spread of the disease,” said Feld.

Public health officials recommend the following precautions to reduce the likelihood of being exposed to plague:

Reduce rodent habitat around the home, work place, and recreational areas. Remove brush, rock piles, junk, cluttered firewood, and possible rodent food supplies, such as pet and wild animal food. Make your home and outbuildings rodent-proof.

  • Wear gloves if handling or skinning potentially infected animals to prevent contact between skin and the plague bacteria. Do not feed or handle wild animals, including squirrels and chipmunks.
  • Use repellent if you could possibly be exposed to rodent fleas during activities, such as camping, hiking, or working outdoors. Products containing DEET can be applied to the skin, as well as clothing, and products containing permethrin can be applied to clothing.
  • Keep fleas off of your pets by applying flea-control products. Pets that roam freely are more likely to come in contact with plague-infected animals or fleas and could bring them into homes. If your pet becomes sick, seek care from a veterinarian as soon as possible.

Household pets, such as dogs and cats, can carry plague-infected fleas home. In rare instances, cats and dogs infected with plague can transmit the disease to humans. Dead rodents or rabbits should be placed in a bag using a long-handled shovel and disposed of in an outdoor trash receptacle.

Symptoms of plague usually develop 1 to 6 days after being infected. They include high fever; extreme fatigue; nausea and vomiting; muscle aches; and sometimes painful swollen lymph nodes (called buboes) or pneumonia.