One of the oldest diseases of mankind leprosy originated in Europe?

Origin of leprosy could be in Europe

In this country, leprosy has long since been eradicated. In other parts of the world, however, infectious disease still poses a major threat to humans. Researchers have now found indications that the origins of the disease may be in Europe.

Every year around 200,000 new cases

Leprosy was widespread in Europe until the 16th century, but today the disease is almost eradicated in countries with developed health care. In some parts of the world, however, it continues to pose a major health threat. More than 200,000 new cases are reported worldwide each year. New insights about the disease are still being gained. Only recently, an international team of researchers reported on studies that showed that leprosy could change the genetic makeup of all Europeans. And now scientists from Germany and Switzerland have found evidence that the origins of the disease could be in Europe.

Leprosy is one of the oldest known diseases of human history. Researchers have now found evidence that the origin of the disease could be in Europe. (Image: pepe / fotolia.com)

New evidence of the history and origin of the disease

Leprosy is one of the oldest known diseases of human history. Sick people were and are exposed to strong stigmatization.

The main cause of the disease is the bacterium Mycobacterium leprae.

But unlike previously thought, not only two, but significantly more leprosy bacteria strains were common in the Middle Ages in Europe, as an international research team with the participation of the Max Planck Institute for the History of Mankind and the Universities of Tübingen and Zurich has found.

These results give scientists new clues to the history and origin of the disease.

Their study was recently published in the journal "PLOS Pathogens".

Medieval genomes reconstructed

The oldest sequenced genome to date is from one of Britain's oldest known leprosy camps, Great Chesterford, England, and dates back to 415-545 AD.

The research team from Germany and Switzerland has now examined samples from around 90 individuals from all over Europe, which showed the bone deformities characteristic of leprosy.

From these samples, which date back to about 400 to 1400 AD, ten medieval genomes were reconstructed. Overall, the genomes include all known strains of leprosy pathogens, including those that occur today in Asia, Africa or North and South America.

"In some cases we have isolated very different bone leprosy strains from the same cemetery", reports the first author of the study Professor Verena Schünemann, who recently moved from the University of Tübingen to the University of Zurich, in a statement.

This demonstrates particularly well the variety of leprosy tribes that circulated on the continent.

The oldest genome of a leprosy pathogen so far

"We have found much more genetic diversity in the leprosy pathogens of ancient Europe than expected," summarizes the lead author of the study Professor Johannes Krause, Director at the Max Planck Institute for the History of Mankind and Research Group Leader at the University of Tübingen.

"All known leprosy tribes have already appeared in medieval Europe, suggesting that leprosy has been widespread in ancient times in Asia and Europe, and that the disease may have its origins in western Eurasia."

The oldest reconstructed genome of M. leprae from England belongs to the same leprosy strain that was discovered in today living squirrels.

"This supports the hypothesis that squirrels and the trade in their skins are factors in the spread of leprosy among middle-aged people in Europe," says Krause.

Even today, most red squirrels in the British Isles are infected with leprosy pathogens.

Leprosy bacteria may already exist much longer than expected

"The dynamics of transmission of leprosy pathogens in human history is not fully understood. It is also unclear exactly where the leprosy originally came from, "says Schünemann.

"We have written testimonies of pre-Christian leprosy, but so far we do not have the samples to confirm at the molecular level."

The new study results lead to the assessment that leprosy bacteria exist for much longer than expected. They are at least several thousand years old.

"The next step is to look for even older samples of leprosy-deformed bones. Well-established methods are now available for identifying potential leprosy cases, "explains Krause. (Ad)