Black death: DNA analyses finds plague bacteria in pandemic that killed 100 million and triggered decline of Roman empire

Mark Prigg
The Mail Online
Tue, 14 May 2013 14:41 UTC

© n/a

The same strain of killer bacteria that caused the Black Death and spread around the world in the mid 1800s may have helped finish off the Roman Empire, researchers have claimed.

DNA analyses of skeletal remains of plague victims from the 6th century AD found traces of Yersinia pestis, the bacterium that causes plague, has already been linked with at least two of the most devastating pandemics in recorded history.

Now researchers believe it also caused the Justinianic Plague of the sixth to eighth centuries, which killed more than 100 million people - and some historians believe contributed to the decline of the Roman Empire.

© Daily Mail

An artist’s recreation of the Byzantine Empire under Justinian I - which was decimated by the plague

The Great Plague, which lasted from the 14th to 17th centuries, included the infamous epidemic known as the Black Death, which may have killed nearly two-thirds of Europe in the mid-1300s.

The Modern Plague struck around the world in the 19th and 20th centuries, beginning in China in the mid-1800s and spreading to Africa, the Americas, Australia, Europe and other parts of Asia.

However, until now researchers have been unsure whether it was also responsible for the Justinianic Plague.

At its peak, 5,000 people per day in Constantinople died from it, killing half the population.

Some historians say the damage was so great to the Persian and Byzantine empires that it made them vulnerable to the Muslim conquests of the next century.

'For a long time scholars from different disciplines have intensively discussed about the actual etiological agents of the past pandemics', said Dr. Barbara Bramanti of the Palaeogenetics Group at the Institute of Anthropology at Johannes Gutenberg University Mainz (JGU).

'Only ancient DNA analyses carried out on skeletal remains of plague victims could finally conclude the debate.'

Dr Bramanti also headed the international team which demonstrated beyond any doubt that Y. pestis also caused the second pandemic of the 14th-17th centuries including the Black Death, the infamous epidemic that ravaged Europe from 1346-1351.

Comment: For an in-depth analysis of the problem of DNA testing and cross contamination read Return of the Black Death: The World's Greatest Serial Killer by Susan Scott and Christopher Duncan from the University of Liverpool. As it is pointed out in New Light on the Black Death: The Viral and Cosmic Connection:

... it is known that the Black Death was carried across the sea to Iceland and that there were two severe and well-authenticated epidemics in the fifteenth century. [...] Yet it is known that no rats were present on the island during the three centuries of the Black Death. Infections continued through the winter when the average temperature was below -3 degrees Celsius, where transmission by fleas is impossible. It is also agreed that there is no mention in any of the accounts of rat mortality during the Black Death. A temperature of between 18 degrees and 27 degrees Celsius and relative humidity of 70% are ideal for flea egg-laying, whereas temperatures below 18 degrees inhibit it. Researchers had collected all the available climatological data for central England during the Black Death and at no time was the average July-August temperature above 18.5 degrees Celsius.

Plagues helped bring down entire civilizations, but they were most likely caused by dangerous viral diseases. For more in-depth reading about the Black Death read Laura Knight-Jadczyk's latest new book Comets and the Horns of Moses.