prairie dog in a grassy area


Plague is a disease caused by the bacteria Yersinia pestis. There are three different forms of plague, depending on how a person becomes infected:

Bubonic plague

is caused when the bacteria enter a break in the skin, like during a flea bite. This is the most common form.

Septicemic plague

is caused when the bacteria get into the bloodstream.

Pneumonic plague

happens when people breathe in droplets that have the bacteria in them when an infected person or animal coughs.

Anyone can get plague. The bacteria is usually found in rodents and the fleas that bite them. Pneumonic plague is the most serious form and the only one that can spread between people/

Common Signs and Symptoms

  • Fever
  • Chills
  • Weakness

Other symptoms of plague may occur, depending on how a person becomes infected. Symptoms appear 1-7 days after being exposed.

Bubonic plague causes headaches and swollen, tender lymph nodes (also called buboes).

Septicemic plague causes abdominal pain, bleeding into the skin and organs, and shock.

Pneumonic plague causes pneumonia with shortness of breath, chest pain, cough, and sometimes bloody or watery mucus.

Talk to your doctor if you think you have plague. Plague is diagnosed based on signs and symptoms and confirmed with a blood test or biopsy. Plague is a very serious illness but is treatable with antibiotics. Treatment is most effective when started as soon as possible.

Plague is widespread in the western United States. Plague was first seen in Colorado in San Miguel County on the Western Slope in 1941 and appeared in several Front Range locations in 1943. Plague is now firmly established and often detected in rock squirrels, prairie dogs, and other species of ground squirrels and chipmunks. In El Paso County, it is also seen in tree squirrels, common in city parks and Front Range residential areas.

What to look for:

If you notice an unusual number of dead wild rodents in your area, contact El Paso County Public Health at (719) 578-3199 and select the option for Environmental Health. Do not handle sick or dead animals.

What you can do:

Because plague is regularly found among wild rodents in El Paso County, it is important to always follow these precautions:

  • Do not feed or touch wild animals, such as prairie dogs, rabbits, chipmunks, squirrels, and other rodents. Do not touch sick or dead animals.
  • Make sure your residence is as rodent-proof as possible.
  • Before and while hiking, wear insect repellent to protect from fleas.
  • Protect pets with appropriate flea control – consult your veterinarian.
  • Keep pets and children away from wild animals.
  • In the United States, plague is most common in the southwest, including Arizona, Colorado, and New Mexico. Plague also occurs in other parts of the world.
  • People are at most risk of plague in areas where they may encounter rodents or their fleas, including ground squirrels, chipmunks, and rats. This may include homes that provide food and shelter for these rodents.
  • It is possible that plague could be used in a biological attack to sicken people. Maine CDC, along with other public health authorities, prepares for the possible, but unlikely, event that this could happen.

If you travel to areas where plague occurs:

  • Avoid contact with rodents and fleas. Do not camp near rodent burrows.
  • Keep fleas off of pets by applying flea control products.
  • Use an EPA-approved repellent during outdoor activities to prevent exposure to fleas.
  • Wear protective gloves when handling animals.

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