Chinese news agency Xinhua recently reported a case of what is believed to be the bubonic plague.

Bubonic plague is the most fatal pandemic in human history. It was responsible for the Black Death, a period in the mid-1300s when half of Europe’s population fell ill and died.

The case was identified in the Chinese region of Inner Mongolia. The affected patient is currently under treatment at a local hospital and in a stable condition, but authorities are cautioning the public of human-to-human infection and urging citizens in the region to report any dead animals or suspected cases of the plague.

A citywide Level 3 warning for plague prevention was issued on Sunday. The warning is expected to be in place until the end of 2020. 

Bubonic plague, known for its high mortality rate if left untreated, causes swollen lymph nodes, fever, chills, and coughing.

China Daily reported a statement from the local health authority: "At present, there is a risk of a human plague epidemic spreading in this city. The public should improve its self-protection awareness and ability, and report abnormal health conditions promptly."

Bubonic Plague can now be treated with the use of antibiotics, but according to the CDC, “plague can still be fatal despite effective antibiotics.” Still, the mortality rate for treated individuals decreases significantly, landing at 1 to 15 percent.