Plague activity present in Colorado


Colorado Department of
Public Health and Environment

A squirrel tested positive for plague in El Paso County recently and the Colorado Department of Public Health and Environment (CDPHE) reminds residents that it’s not uncommon for plague to be present this time of year. 

Simple precautions can keep the risk of transmission to humans very low.

“Plague has been present in Colorado since at least the 1940s and cases in wild rodents in the state are reported most years,” said Dr. Jennifer House, state public health veterinarian. “While we see most plague activity during the summer, the disease can be found in rodents year-round and sometimes spills over into other wildlife species as well as domestic cats and dogs.”

Plague was found in animals last summer in areas of Adams and Broomfield counties, and two cases of human plague infection were reported in 2020. Both people had exposure to sick animals and both survived.

People should take the following precautions to protect themselves and their pets:

• Do not directly handle any wildlife.

• Keep pets away from wildlife, especially dead rodents and rabbits.

• Don’t let dogs or cats hunt prairie dogs, other rodents or rabbits.

• Don’t allow pets to roam freely.

• Treat all pets for fleas according to a veterinarian’s advice.

• Do not feed wildlife — this attracts them to your property, brings them in close contact and increases the risk of disease transmission.

• Be aware of rodent and rabbit populations in your area and report sudden die-offs or multiple dead animals to your local health department.

Plague is most commonly spread to people by the bite of an infected flea, but also may be transmitted by infected animal tissues, fluids or respiratory droplets. People with direct exposure to fleas or wildlife in the affected areas may be at risk. 

People who think they have been exposed should contact a health care provider immediately. Symptoms include sudden fever, headache, chills and weakness. Some patients may also have tender, painful lymph nodes. While there are no publicly available vaccines to prevent plague in people, if caught early, both people and pets can be successfully treated with antibiotics.

For more information about plague, visit CDPHE’s plague Web page or the Centers for Disease Control and Prevention.