DHAKA: Plague has been a scourge on humanity for far longer than previously thought, ancient DNA shows.

Samples taken from the teeth of seven bodies contained traces of the bacterial infection in the Bronze Age, bbc.com reported.

They also showed it had, at the time, been unable to cause the bubonic form of plague or spread through fleas - abilities it evolved later.

The researchers, at the University of Copenhagen, say plague may have shaped early human populations.

Human history tells of three plague pandemics:

    The Plague of Justinian began in AD541 and killed more than 25 million people
    The Black Death started in China in 1334 and claimed the lives of up to half of Europeans
    The Modern Plague, in China, emerged in the 1860s and led to 10 million deaths

There have also been suggestions of earlier plagues, such as the Plague of Athens in 430BC.

But now scientists have hurtled millennia back in time by studying 101 ancient skeletons.

The teeth of seven of them, from across western Europe and central Asia, contained evidence of Yersinia pestis infection - the killer bacterium that causes plague.

The oldest was 5,783 years old.

The analysis of those samples, published in the journal Cell, showed the bacterium was still lacking some of the killer traits that led it to cause death on a global scale.

BDST: 1149 HRS, OCT 23, 2015
RS