Colorado public health officials have confirmed a human case of plague in a Pueblo County resident, according to the Pueblo Department of Public Health and Environment.
Plague is very rare, with an average of seven human plague cases reported annually in the U.S., according to the CDC.
While the disease killed millions of people in Europe during the Middle Ages, nowadays, it is a rare cause of illness in rural areas of the southwestern U.S., particularly in New Mexico, Arizona and Colorado, the agency said.
Certain regions of Africa and Asia have also reported cases over the past few years.
A potentially life-threatening disease, plague is caused by the bacterium Yersinia pestis. It is usually passed to humans through the bite of an infected rodent flea or by handling an infected animal, according to the Pueblo Department of Public Health.
Symptoms can include sudden fever, chills, severe headache, muscle aches, swollen lymph nodes, nausea and vomiting, per the CDC.
Plague can be cured with antibiotics, but they must be administered promptly to prevent serious illness or death.
Health officials urged anyone who develops symptoms of plague to seek medical care immediately.
In order to avoid infection, health officials suggest people take precautions, including avoiding contact with dead animals, regularly treating pets for fleas and eliminating places in and around the home where rodents can breed.