DNA Analysis taken at the cemetery of lepers of the XV century, helped to solve the mystery of why the terrible infection, once considered the curse of humanity, disappeared from Western Europe. As it turned out, the evolution of our body led to the victory over the disease, reports RawStory with reference to the journal Science.
Scientists find out why Europeans no longer suffer from leprosy
In the 15th century, 1 in 30 people in Western Europe fell victim to leprosy or leprosy. In drawings and engravings of the time, lepers are almost as common as Christ or the virgin Mary. But then, after the Crusades, a dangerous infection mysteriously left the continent.
Scientists wondered whether this was a consequence of a mutation of the causative agent of leprosy Mycobacteria leprae or changes in the immunity of the Europeans themselves. The results of the study proved the second.
One of the authors of the study, Stuart Cole, an employee Of the research Institute in Lausanne, said that he received a DNA sample from a tooth taken from a mass grave site in a former leper settlement. The resulting sample contained human DNA, micro-organisms, and foreign DNA from the surrounding soil, but Cole’s team was able to completely reconstruct the genome of the 600-year – old leprosy-causing bacterium. It turned out that it is identical to the one that affects people in developing countries today.
“If the reason that people stopped getting sick is not in the pathogen, then it must lie in the carrier – that is, in ourselves,” the scientist said.
Stuart Cole and his colleagues believe that modern Europeans have a gene responsible for immunity to leprosy. Today, this infection can be treated with antibiotics if it is diagnosed at an early stage. In developing countries, hostility towards patients often prevents them from seeking help, which encourages further transmission of the infection and causes irreversible damage to the patient and others.
“With information about specific genes and proteins, we can develop strategies to prevent and control the disease, as well as invent the necessary medications,” says Cole.
Leprosy is transmitted during close contact with infected people who are not undergoing treatment. Basically, leprosy affects the skin, the mucous membrane of the upper respiratory tract and superficially located nerves. In advanced cases, damage to the skin and nerves irreparably disfigures the person. Basically, leprosy is common in tropical countries. Although the number of cases worldwide continues to fall, the disease is still widespread in parts of Brazil, South Asia (India, Nepal, Burma), East Africa, and the Western Pacific.