Scientists have found out when and where did the tuberculosis. The journal Nature Genetics on Sunday published as four papers on tuberculosis and its agents - in particular, the scientists found that the disease that annually kills one to two million people, has appeared in Africa about 70,000 years ago, and has since followed for humanity .
The causative agent of tuberculosis, mycobacterium Mycobacterium tuberculosis, better known as the tubercle bacillus. German microbiologist Robert Koch discovered the organism in March 1882. The current vaccine against tuberculosis, BCG, which is usually administered to kids in the first days after birth, can not prevent the disease in adults, especially in areas where the infection is prevalent.
A major problem in the treatment of tuberculosis is its ability to rapidly develop resistance to medicines. Thus, according to senior phthisiatrician Russian Peter Jablonski, in 2012, in Russia 24%, or nearly one in four cases of TB had drug-resistant form of the disease. The authors of an article in Nature Genetics write that today in some parts of Eastern Europe multidrug resistance recorded in almost 50% of cases, and some strains are found in India and Iraq, is almost terminally.
Sebastien Gagne from the Swiss Institute of Tropical and Public Health, and his colleagues have decoded the genome of 259 strains of Koch#39;s bacillus and restored the evolutionary tree of the deadly disease. It turned out that the agent of tuberculosis appeared in Africa at least 70,000 years since man nazad.S and tuberculosis alongside migrated out of Africa and spread around the world, with which accompanied this change in the lifestyle of ancient people were a powerful stimulus for the evolution of the disease . Gagne said that the diversity of strains has increased dramatically, when people began to actively settle in new areas.
The researchers conclude that TB, unlike many other infectious diseases not transmitted to humans from domesticated animals - simply because it appeared much earlier than the last, said Gagne. Transmission from person to person, most likely, was made possible in the so-called Neolithic demographic transition: after the occurrence of Agriculture about 9-10 thousand years ago, the birth rate has increased dramatically as the number of people residing in stable groups.
The authors believe that the analysis of the history of Mycobacterium tuberculosis can help to predict future directions of its development, including the development of new effective treatments for the disease, which without proper kills half of all patients.
