Bubonic Plague

Avery, Maddi, & Jade

Bubonic Plague

The Bubonic plague is a zoonotic disease, circulating mainly among small rodents and their fleas. It is one of three types of bacterial infections caused by Yersinia pestis, which belongs to the family Enterobacteriaceae. The Bubonic Plague is also known as The Black Death. Without treatment, the bubonic plague kills about two thirds of infected humans within 4 days. The plague killed many people of the working population. The deaths caused wages rise and some historians saw this as a turning point in European economic development.

Who did it impact?

The Bubonic Plague killed a third of Europe's population and it was most commonly found in places with high population density and poor sanitation. Although Europe was devastated by the disease, the rest of the world handed it much better. In India, the population rose from a population of 91 million in 1300, to 97 million in 1400, to 105 million in 1500. Sub-Saharan Africa and Scandinavia remained unaffected by the plagues.


Because medical technology was not developed until recently, doctors were only making educated guesses as to what they thought the plague was caused by. They thought that the plague was caused mostly by the combination of humidity, poor sanitation, and decaying unburied bodies. They recommended moving out of infected areas to get clean air. They thought that if you move out of densely populated areas, you will have more access to the so called "clean air". This did help, but the problem wasn't actually the "infected air", it was the poor sanitation and infected rats in the cities. The plague spread quickly in poor sanitational areas and high population density, but the doctors sent people away from these areas. The doctors thought that they were getting people away from "infected air" when they were actually getting people away from the poor sanitation.

How Did It Start & Spread

The Black Death is thought to have started in China or Central Asia. It then travelled along the Silk Road and reached the Crimea by 1346.It was then thought to have been carried by Oriental rat fleas living on the black rats that were regular passengers on merchant ships. The Black Death spread throughout the Mediterranean and Europe and is estimated to have killed 30–60 percent of Europe's population. In the 14th century, the plague reduced the world population from an estimated 450 million to a number between 350 and 375 million.

Essential Question

What were the effects of the Bubonic Plague on the people of Europe?