Placeholder Image

Subtitles section Play video

  • - [Narrator] Plague is notorious for causing

  • mass sickness and devastation.

  • But as much tragedy as the disease has caused,

  • it also helped drive crucial scientific and social progress.

  • Plague is an infectious disease

  • caused by the bacterium Yersinia pestis.

  • It mainly affects rodents, and spreads by way of insects.

  • Because of these insect carriers,

  • plague has been passed onto humans

  • with devastating consequences.

  • Three major plague pandemics have occurred in human history.

  • And while they occurred centuries apart,

  • they shared similar traits

  • that paved the way for the spread of disease.

  • One cause of plague pandemics

  • was the rise of international trade.

  • Trade routes connected once-isolated communities

  • and created large economic networks.

  • But by facilitating the movement

  • of goods between communities,

  • trade routes also facilitated the movement of germs.

  • International trade was an impetus

  • for the first plague pandemic on record,

  • the Plague of Justinian.

  • In the sixth century, outbreaks began in Egypt

  • and, thanks to land and sea trade routes,

  • they spread throughout the Byzantine Empire.

  • Named after the emperor at the time,

  • the Plague of Justinian is estimated to have wiped out

  • about half of Europe's population.

  • Growing economies also made way for urbanization

  • and a rising urban population.

  • This resulted in crowded neighborhoods

  • and the accumulation of waste,

  • which created unsanitary living conditions.

  • Cities and their residents essentially became incubators

  • for germs and diseases.

  • This was particularly evident in the second

  • and most infamous plague pandemic.

  • In the 14th century,

  • Europe was experiencing an economic and population boom,

  • especially in cities.

  • Proper waste management did not exist at the time,

  • making cities vulnerable to disease.

  • After trade routes brought plague from Asia,

  • where it killed millions in China and the Middle East,

  • the disease wiped out about a third of Europe's population,

  • earning itself the moniker the Black Death.

  • What also aided in the transmission of the disease

  • was the lack of medical knowledge.

  • For most of human history,

  • the cause of illnesses, germs, was unknown,

  • making sicknesses like the plague a mystery.

  • This lack of knowledge drove the spread of disease

  • as recently as the 19th century.

  • Outbreaks in northwest India

  • eventually reached major port cities in China.

  • In just over a century,

  • plague was exported throughout the globe

  • and caused outbreaks in every continent except Antarctica,

  • making it the most widespread pandemic in history.

  • This plague pandemic, however, was the last.

  • In 1894, scientists discovered the bacteria

  • behind the plague outbreaks.

  • Their discovery helped further developments in microbiology,

  • medicine, urban planning, and sanitation methods,

  • which led to the treatment and prevention of the disease.

  • Economic expansion, urbanization,

  • and a lack of medical knowledge

  • contributed to the disastrous spread of plague.

  • In turn, however, the disease helped catapult

  • crucial advancements in science and public health,

  • very well making plague pandemics a thing of the past.

- [Narrator] Plague is notorious for causing

Subtitles and vocabulary

Click the word to look it up Click the word to find further inforamtion about it