The Black Death: Plague that killed millions is able to rise from the dead

Black rats are also implicated in both outbreaks, which took place 800 years apart

Science Editor

Two of the most devastating outbreaks of plague in history, each of which killed more than half the population of Europe, were caused by different strains of the same infectious agent, a study has revealed.

The Justinian Plague of the 6th Century AD, which is credited with leading to the final demise of the Roman Empire, and the Black Death of the 14th Century, were both caused by the independent emergence of the plague bacterium from its natural host species, the black rat, scientists said.

An analysis of bacterial DNA extracted from the teeth of two plague victims who died in the early 6th Century in present-day Bavaria, Germany, has shown that they were infected with the bacterium Yersinia pestis, the same plague agent known to have caused the Black Death 800 years later.

However, a detailed comparison of the bacteria’s DNA sequences has revealed that the two outbreaks were quite independent of one another. Each pandemic was the result of different Yersinia strains, indicating the independent emergence from the black rat on two separate occasions, the researchers said.

Although the strain behind the Justinian Plague died out completely, the strain that caused the Black Death probably re-emerged a few centuries later to cause the so-called Third Plague pandemic which began in the mid-19th Century in China and went on to kill about 12 million people in China and India alone, although it did not travel to Europe.

The scientists behind the study, published in the journal The Lancet Infectious Diseases, warned that the findings suggest there is a possibility of another pandemic strain of plague to emerge from the existing reservoir of Yersinia bacteria living in the current rodent population.

“The key point here is that this bug can re-emerge in new forms in humans and can have a tremendous impact on human mortality. It’s done it three times in the past and we should be monitoring it for the future,” said Hendrik Poinar, director of the Ancient DNA Centre at Canada’s McMaster University in Hamilton, Ontario.

The Justinian Plague, named after the Roman emperor who died of it, probably began in Asia but first came to prominence when it swept through the eastern Roman capital of Constantinople. It killed at least 50 million people, almost half the global population at the time, and is generally regarded as the first documented outbreak of bubonic plague.

The DNA analysis of the full Yersinia genome extracted from the two Bavarian plague skeletons, however, has shown that the pandemic died out completely within a couple of centuries without leaving any bacterial descendants, Dr Poinar said.

“The research is both fascinating and perplexing. It generates new questions which need to be explored, for example why did this pandemic, which killed somewhere between 50 and 100 million people die out?” Dr Poinar said.

The scientists extracted overlapping fragments of Yersinia DNA from the teeth of the two plague victims and were able to build the entire genome of 4.6 million “base pairs” – the individual letters of the genetic alphabet that comprise the bacterium’s genetic code.

“We know the bacterium Y. pestis has jumped from rodents into humans throughout history and rodent reservoirs of plague still exist today in many parts of the world,” said Dave Wagner of Northern Arizona University in Flagstaff, Arizona, the lead author of the study.

“If the Justinian plague could erupt in the human population, cause a massive pandemic, and then die out, it suggests it could happen again. Fortunately, we now have antibiotics that could be used to effectively treat plague, which lessens the chances of another large scale human pandemic,” Dr Wagner said.

Long periods of warm, wet weather preceded both the Justinian Plague and the Black Death, which was thought to have resulted in an explosion in the rat population. Scientists suspect that plague outbreaks eventually die out as people develop a natural immunity to the bacteria.

“Another possibility is that changes in the climate became less suitable for the plague bacterium to survive in the wild,” Dr Wagner said.

Start your day with The Independent, sign up for daily news emails
ebooks
ebooksAn introduction to the ground rules of British democracy
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
SPONSORED FEATURES
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Recruitment Genius: Head Chef

£22000 - £25000 per annum: Recruitment Genius: This Garden Centre complex base...

Recruitment Genius: Buyer

£36000 - £38000 per annum: Recruitment Genius: A Buyer is required to join thi...

SThree: Trainee Recruitment Consultant

£20000 - £25000 per annum + OTE £45K: SThree: SThree Group have been well esta...

SThree: Trainee Recruitment Consultant

£20000 - £25000 per annum + OTE £45000: SThree: SThree Group have been well es...

Day In a Page

Turkey-Kurdish conflict: Obama's deal with Ankara is a betrayal of Syrian Kurds and may not even weaken Isis

US betrayal of old ally brings limited reward

Since the accord, the Turks have only waged war on Kurds while no US bomber has used Incirlik airbase, says Patrick Cockburn
VIPs gather for opening of second Suez Canal - but doubts linger over security

'A gift from Egypt to the rest of the world'

VIPs gather for opening of second Suez Canal - but is it really needed?
Jeremy Corbyn dresses abysmally. That's a great thing because it's genuine

Jeremy Corbyn dresses abysmally. That's a great thing because it's genuine

Fashion editor, Alexander Fury, applauds a man who clearly has more important things on his mind
The male menopause and intimations of mortality

Aches, pains and an inkling of mortality

So the male menopause is real, they say, but what would the Victorians, 'old' at 30, think of that, asks DJ Taylor
Man Booker Prize 2015: Anna Smaill - How can I possibly be on the list with these writers I have idolised?

'How can I possibly be on the list with these writers I have idolised?'

Man Booker Prize nominee Anna Smaill on the rise of Kiwi lit
Bettany Hughes interview: The historian on how Socrates would have solved Greece's problems

Bettany Hughes interview

The historian on how Socrates would have solved Greece's problems
Art of the state: Pyongyang propaganda posters to be exhibited in China

Art of the state

Pyongyang propaganda posters to be exhibited in China
Mildreds and Vanilla Black have given vegetarian food a makeover in new cookbooks

Vegetarian food gets a makeover

Long-time vegetarian Holly Williams tries to recreate some of the inventive recipes in Mildreds and Vanilla Black's new cookbooks
The haunting of Shirley Jackson: Was the gothic author's life really as bleak as her fiction?

The haunting of Shirley Jackson

Was the gothic author's life really as bleak as her fiction?
Bill Granger recipes: Heading off on holiday? Try out our chef's seaside-inspired dishes...

Bill Granger's seaside-inspired recipes

These dishes are so easy to make, our chef is almost embarrassed to call them recipes
Ashes 2015: Tourists are limp, leaderless and distinctly UnAustralian

Tourists are limp, leaderless and distinctly UnAustralian

A woefully out-of-form Michael Clarke embodies his team's fragile Ashes campaign, says Michael Calvin
Blairites be warned, this could be the moment Labour turns into Syriza

Andrew Grice: Inside Westminster

Blairites be warned, this could be the moment Labour turns into Syriza
HMS Victory: The mystery of Britain's worst naval disaster is finally solved - 271 years later

The mystery of Britain's worst naval disaster is finally solved - 271 years later

Exclusive: David Keys reveals the research that finally explains why HMS Victory went down with the loss of 1,100 lives
Survivors of the Nagasaki atomic bomb attack: Japan must not abandon its post-war pacifism

'I saw people so injured you couldn't tell if they were dead or alive'

Nagasaki survivors on why Japan must not abandon its post-war pacifism
Jon Stewart: The voice of Democrats who felt Obama had failed to deliver on his 'Yes We Can' slogan, and the voter he tried hardest to keep onside

The voter Obama tried hardest to keep onside

Outgoing The Daily Show host, Jon Stewart, became the voice of Democrats who felt the President had failed to deliver on his ‘Yes We Can’ slogan. Tim Walker charts the ups and downs of their 10-year relationship on screen