FLAGSTAFF, Ariz. — A resident of northern Arizona has died of pneumonic plague, health officials said Friday. Plague is rare to humans, with on average of about seven cases reported annually in the U.S., most of them in the western states, according to federal health officials.

Officials said the resident died from pneumonic plague, a severe lung infection. The risk to the public remains low.

Pneumonic plague is both “the least common and most dangerous type of plague,” according to the Cleveland Clinic.