What was the Black Death? Plague explained, how many people died and how it affects our health 700 years later

The Black Death is viewed by historians and scientists alike as one of the deadliest pandemics in human history. The devastating plague swept through large sections of Europe in the mid-1300s and even threatened to end human existence.

Nearly 700 years have passed since the bubonic plague, but, according to a new study, it’s still affecting our health nearly seven centuries later - here is everything you need to know.

What was the black death?

The Black Death was a highly contagious and fatal pandemic, and has been labelled by historians as the “Great Mortality” due to the number of deaths it caused. It was the second greatest natural disaster to strike Europe during the late middle ages, following the great famine that ran from 1315 to 1317.

During the Black Death, three different forms of the plague manifested itself across Europe and North Africa. The first signs of the plague came from Crimea and Asia in 1347, and it is believed that the bubonic plague was passed on from rats.

How many people died in Europe from the Black Death?

The plague was one of the greatest disasters in recorded history which took Europe’s population over 150 years to recover from the effects.

It is believed that at least 25 million people died in Europe between 1347 and 1352 - this number equates to over 40% of the population in Europe at the time.

The mortality rate of the Black Death is believed to have been over 200 times higher than the one estimated for Covid-19, according to geneticist Luis Barriero at the University of Chicago.

How did people survive Black Death?

According to Barriero, those that survived Black Death had a slightly different makeup in their genes that helped protect them against the plague pathogen. Those survivors then passed those genes down to their descendants and it is believed that many people in Europe still carry these mutations today.

Therefore, it’s thought that the Black Death actually had an effect on human evolution.

How does Black Death affect people today?

A new pioneering study analysing the DNA of old skeletons found a link between the mutations that helped people survive the plague and autoimmune diseases which are affecting people today.

The new findings were published in the journal Nature and focused on a gene called ERAP2. The evidence suggests that those with the right mutations had a 40% higher chance of surviving the plague 700 years ago. It is believed to be the biggest evolutionary advantage ever recorded in humans, according to David Enard at the University of Arizona.

The ERAP 2 gene plays a pivotal role in helping the immune system respond quickly to an infection. In turn it allows them to kill invading pathogens at a much quicker rate.

However, this gene can also come at a price as it is believed to be linked to autoimmune diseases such as Crohn’s disease and rheumatoid arthritis.

Maria Avila Arcos at the National Autonomous University of Mexico said: “If your immune system is super strong, then that can lead to autoimmune diseases. That’s kind of the balance.”