The case marked the state’s first plague death since 2015, and the second confirmed incidence of plague in Colorado this year.

Two people in the state became infected with plague last year after having close contact with sick animals but survived, according to the Denver Post.

Across the U.S., there were five cases of plague in the United States in 2020, with one death.

Roughly 85 percent of human plague cases are transmitted through flea bites, although house cats that roam outdoors can bring infected fleas inside.

“And it spread from the city of San Francisco by the rats becoming infected in the city, and then having contact with wild animals in the counties outside of San Francisco—California ground squirrels were the right kind of ecological rodent host for the plague bacillus.

There are several different manifestations of plague, and about seven or eight plague-related deaths annually in the United States, Jones explained, describing the recent Colorado case as part of a normal level of plague infections seen each year.

So this is why people can still die of plague, because by the time the lymph nodes really start to swell up, especially in children, the bacteria will have spread and multiplied all around the body.”.

Things can get dire if a case of plague infects a victim’s lungs, a condition known as pneumonic plague, which makes up about 10 percent of all plague cases in the U.S.