The bacterium that wiped out millions in Europe in the Black Death pandemic of the 1300s lives on, and officials say it's resurfaced in fleas in Arizona. Navajo County public health officials warn on Facebook that Yersinia pestis, better known as the plague, can be transmitted to humans and other animals through bites by infected fleas or via direct contact with an infected animal. The officials ask locals near Taylor, Ariz., to leash dogs, regularly treat pets to protect against flea bites, stay away from rodent burrows, and use insect repellent. Infected people tend to experience weakness, headaches, chills, fever, muscle pain, and swollen lymph glands within two weeks of exposure, reports Live Science.
The Washington Post reports that the bacterium poses a "potentially grave threat" to people and their pets, particularly cats. If treated early enough, antibiotics can cure the disease, per the county's health department. The disease is typically passed from fleas to prairie dogs and other rodents, so a sudden die-off of these animals can sometimes signal the presence of the bacterium. While a plague vaccine for prairie dogs reported in the journal EcoHealth looks promising, the disease can be deadly in humans if not treated right away. Most cases are reported in the Southwestern US, with about seven fatalities a year. (Santa Fe saw three cases in June alone.)