Black Death, the historical plague pandemic in the mid-fourteenth century, may have been hiding in Europe for more than 400 years, a new study has found.

Black Death is undoubtedly the most famous historical pandemic. Within only five years it killed 30-50 per cent of the European population, researchers said. Unfortunately it did not stop there. Plague resurged throughout Europe leading to continued high mortality and social unrest over the next three centuries.

With its nearly worldwide distribution today, the once omnipr-esent threat of plague is all but absent in western Europe, the researchers said. Scie-ntists led by members of the Max Planck Institute for the Scie-nce of Human History in Germany, have taken one important step forward to understanding the European plagues of our not-so-distant past.

They report the reconstruction of complete pathogen genomes fro-m victims of the Great Plague of Marseille (1720-1722), which is conventionally assumed to be the last outbreak of medieval plague in Europe. Using teeth from plague pits in Marseille, the team was able to access tiny fragments of DNA that had been preserved for hundreds of years.

“We faced a significant challenge in reconstructing these ancient genomes,” said Alexander Herbig. “To our surprise, the 18th century plague seems to be a form that is no longer circulating, and it descends directly from the disease that entered Europe during the Black Death, several centuries earlier.”

Being distinct from all modern forms of plague, the scientists believe they have identified an extinct form of the disease. Lead author Kirsten Bos cautioned that the geographical source of the disease cannot be identified yet. Marseille was a big hub of trade in the Mediterranean, so the Great Plague co-uld have been imported from any number of places by ship.

“Our results suggest that the disease was hiding somewhere in Europe for several hundred years,” Bos said. “It’s a chilling thought that plague might have once been hiding right around the corner throughout Europe, living in a host which is not known to us yet,” said Johannes Krause, director of the department of Archaeoge-netics at MPI.