14 DAY TRIAL // Scientists writing in yesterday's, September 1, issue of the journal Nature Genetics argue that, according to their investigations, tuberculosis has been around for at least 70,000 years.
The infectious disease, which happens to be one of the deadliest known to science, is said to originate in Africa. What's more, it appears that it reached other continents together with the first migratory modern humans.
Specialists say that, as far as they can tell, the emergence and evolution of different tuberculosis strains is very much intertwined with the history of humanity.
Researcher Sebastien Gagneux says that “The evolutionary path of humans and the TB bacteria shows striking similarities.”
This suggests that humans have a very close relationship with tuberculosis. Thus, not only did the two emerge in the same part of the world, but they also traveled out of Africa and came to populate other regions together.
“We see that the diversity of tuberculosis bacteria has increased markedly when human populations expanded,” said biologist goes on to say.
Otherwise put, tuberculosis became more common and more virulent when humans started living in fairly large groups.
Researchers at the Swiss Tropical and Public Health Institute explain that, it order to pin down the age and the point of origin of this infectious disease, they sequenced the genome of as many as 259 different Mycobacterium tuberculosis strains.
These strains were collected from different parts of the world and allowed the researchers to piece together a so-called genetic pedigree of the deadly bacteria.
The fact that tuberculosis came into being about 70,000 years ago, long before humans started domesticating animals, indicates that, unlike other infectious diseases, this one did not jump from animals to people.
Presently, tuberculosis kills roughly 1-2 million people yearly. Most of the deaths are reported in developing countries.
Scientists hope that a better understanding of how the disease emerged and how it evolved will one day lead to the development of better treatment options for the people affected by it.