Plague activity present in Colorado; people can take precautions to prevent exposure

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DENVER: After a squirrel tested positive for plague in Jefferson County last week, the Colorado Department of Public Health and Environment reminds residents that it’s not uncommon for plague to be present this time of year, and 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 Colorado 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 has been found this summer in animals in limited access areas of Adams and Broomfield counties. In addition, the first case of human plague infection in the state since 2015 was diagnosed earlier this summer in a resident from southwest Colorado who had exposure to sick squirrels. The patient had septicemic plague, which is in the blood and cannot be spread to other people. The resident recovered, and no other cases were identified.

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, weakness, and tender, painful lymph nodes. While there are no publically available vaccines to prevent plague in people, if caught early, it can be successfully treated with antibiotics in both people and pets.

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