What you need to know about the Bubonic Plague that has China on high alert

Published July 8, 2020, 4:33 PM

by Paola Navarette

A city in northern China has put control measures in place after one confirmed case of the disease, which caused the Black Death in the Middle Ages. 

A herdsman from a city in Inner Mongolia was confirmed to be infected with bubonic plague, health officials said, a reminder how even as the world battles a pandemic, old infectious threats remain.

Authorities raised the plague warning on July 5, warning residents against hunting, eating, or transporting potentially infected animals such as marmots. 

The bubonic plague was once the world’s most deadly disease, and it still remains rare despite its fearsome reputation. Here’s what you need to know.

What is bubonic plague?

Plague is one of the deadliest bacterial infections in human history. It has killed tens of millions of people around the world in three major pandemics, with about a third of Europe’s population wiped out in the 1300s. 

It is caused by a bacterium called Yersinia pestis, which live in some animals—mainly rodents—and their fleas. The China Center for Disease Control said the plague can be treated clinically with a variety of effective antibiotics if caught early.

How does infection occur?

The bacteria are transmitted to humans through the bites of fleas who have bitten infected animals like rats, rabbits, and squirrels. 

Bites from infected fleas are the most common cause of bubonic plague infection, but the pneumonic variant—where the bacterium is breathed into the lungs—is more dangerous because it is spread through coughing. A rarer variant of the diseases is septicaemic plague, which infects the bloodstream.

What are the symptoms?

People infected with the plague usually develop symptoms two to six days after infection. Along with painful, swollen lymph nodes, they may also experience fever, chills, cough, fatigue, muscle ache. Infection can also affect the lungs, causing chest pain, cough, and difficulty in breathing. 

Is there a treatment or cure? 

Plague can be successfully treated with antibiotics. Once a patient is diagnosed with suspected plague they should be hospitalized and, in the case of pneumonic plague, medically isolated. Laboratory tests should be done, including blood cultures for plague bacteria and microscopic examination of lymph nodes and blood. To prevent a high risk of death in patients, antibiotics should be given as soon as possible, preferably within 24 hours of the first symptoms.