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

The patient was recently treated at an emergency department in Flagstaff and died the same day, Northern Arizona Healthcare said.

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