Once scientist have analyzed DNA samples taken from a mass grave where the bodies of people affected by leprosy were buried in the eleventh century, they have found out why the leprosy vanished from Western Europe.
According to experts it appears that a genetic change produced in the human body has led individuals immune to this disease.
In the fifteenth century, leprosy affect one in every 30 individuals from Western Europe and the number of cases is also indicated by the sculptures and paintings of that period. However, in the era of the Crusades, the disease has mysteriously disappeared from the continent.
Now, scientists have wondered whether the bacteria that cause leprosy mycobacterium leprae, mutated becoming less violent, or whether Europeans have become immune to it. According to the new study, the bacteria didn’t mutate, but men did.
Although DNA samples extracted from the bones very difficult, scientists have managed to collect a tooth of an individual who died 600 years ago. The material found was “a mix of human DNA and DNA microorganisms from contaminated soil and other bones nearby,” said Stewart Cole, one of the study authors, Ecole Polytechnique Fédérale in Lausanne. Based on these samples, scientists have rebuilt a strain of leprosy have sequenced the genome. The results indicated that this strain was identical to that found today in communities leper developing countries.
Scientists believe that certain genes that makes some people resistant to leprosy spread among the European population, individuals giving them immunity against the disease.
Today such infections are treated with antibiotics and can be quickly cured if detected in time.
Ecole also explained that understanding the history of a disease may inform scientists and doctors on the approach that can rein in current or future diseases. “Having them information on certain genes and disease-specific proteins can help us to develop prevention strategies,” he added.