SCIENTISTS AT AN Irish university have traced the origins of Europe’s deadliest plague wave – the Black Death – back to an ancient plague in China.

Dr Mark Achtman and his team of medical geneticists at University College Cork concluded that the Justinian plague which killed half the population of Europe in the 6th century; the Black Death, which raged through Europe intermittedly from 1347 to 1666; and a plague that began in China’s Yunnan province in 1894, reaching Hawaii in 1899 and San Francisco in 1900, could all be tied together in a plague ‘family tree’.

A team of biologists from France and Germany reported findings last month that the Black Death was caused by the bacterium known as Yersinia pestis. The scientists had analysed ancient DNA and proteins from mass plague graves from across Europe to come to their conclusion.

Then, Dr Achtman and his Cork-based team looked at genetic variations in living strains of Yersinia pestis in order to match up the points at which it mutated with major plague outbreaks.

In a report published in Nature Genetics yesterday, they found that the origin of their ‘plague tree’ was rooted in China. Dr Achtman said:

What’s exciting is that we are able to reconstruct the historical routes of bacterial disease over centuries.

The plagues would have been carried along the Silk Road to Europe. Dr Achtman said also that the bacterium probably originated in China because its natural hosts are species of rodents such as marmots and voles, which are common throughout that terrain.

The Black Death devastated Europe for over 300 years. It killed around 30 per cent of the continent’s population and struck every decade or so. Its last major outbreak was the Great Plague of London in 1665-6.