Scientists can now tell the world what is the main factor that makes plague responsible for many deaths.
The fact that the disease killed many researchers made this name "black death", but until now, the sound is not authorized to certify to the facts of what led to such rapid growth, great.
Scientists have found the answer after they learn some medieval bodies from a cemetery in London.
They were tested in their laboratory plague germs and they are able to say what makes the bacteria responsible for Black Death expansion is so strong.
It seems that DNA Yersinia pestis view of the fact that Europe from the 14th century did not have strong enough immune system to fight the deadly microbes.
"This is the first pandemic Black Death plague human history. People (immunology) a sophisticated and adapted to it, "said Johannes Krause, a highly respected scientist and professor at University of Tuebingen, Germany.
His findings were published on Wednesday, the British journal Nature.
Scientists have determined that, because of their inability to fight microbes, people have no other way to protect themselves against pathogens feared by many, that seems to retain its shape and characteristics of an historic sixth century.
The effect was devastating, because the study proves that no viruses or other types of pain managed to erase from the face of the earth so many individuals.
People living in the 14th century facing the most deadly epidemic ever experienced by mankind.
Its development began in China. Later, he began to perform millions of victims in Europe. From 1347-1351, Black Death kill one of three European populations, and 1 in 12 people worldwide.
Surprisingly, the scientists discovered that microbes are still medieval in connection with the researchers plagues to remain under control at this time.
Never the less, modern can not be compared, in terms of effects, with their fathers are far more formidable.
"Based on the reconstructed genome, we can say that the medieval plague close to the root of all modern humans pathogenic plague strain," concluded Krause.