Fleas in two Arizona counties tested positive for the Bubonic plague — the same disease that killed millions of people in the 14th century throughout Africa, Asia, and Europe, public health officials say.
Navajo County public health officials announced Friday that fleas collected near the town of Taylor tested positive for Yersinia pestis, the bacteria that causes the Bubonic plague, the Associated Press reports.
The announcement came one week after Coconino County officials first discovered fleas in the area found to be carrying the plague.
KNXV reports that Coconino County officials first discovered the plague-infested fleas in the Red Lake area last week but also found fleas in the Doney Park area that tested positive for the disease.
Officials in both counties have notified residents and are monitoring the situation.
Arizona has been host to a host of plague outbreaks among prairie dogs over the years.
The International Business Times reported in 2015 that another outbreak of the plague took place among prairie dogs in Flagstaff. Public health officials became aware of the plague outbreak after testing several fleas in animal burrows for Yersinia pestis.
Authorities say indicators that the plague is spreading include the sudden death of a large number of prairie dogs and rodents at the same time.
Public health officials warn residents that if they notice a sudden decrease in rodents to call their local health department.
According to the Centers for Disease Control (CDC), 15 humans had been infected with the Bubonic plague in 2015. The CDC says that most outbreaks of the plague among humans take place in the Southwest region of the U.S.