Tuberculosis Originated From Humans Not animals in Africa 70,000 Years ago

Tuberculosis, one of the deadliest infectious diseases of humankind migrated out of Africa 70,000 years ago hand in hand with modern humans, a team of international scientists say.

Tuberculosis is one of the deadliest infectious diseases in humans. It is a global threat that kills 50 percent of the people if left untreated. Every year nearly 1-2 million deaths occur due to TB especially in the developing countries.  .

 It was believed by many that this deadly disease originated in animals nearly 10,000 years ago and gradually invaded humans. TB originated during the Neolithic Demogrpahic Transition (NDT) in Africa, the time when the human population was expanding and agriculture was gaining prominence.  

But the new study conducted by an international group of researchers led by Sebastien Gagneux from the Swiss Tropical and Public Health Institute (Swiss TPH) has opposed the previous findings stating humans and TB originated from the same place 70,000 years ago in humans in Africa and migrated and slowly spread all over the world.

In the latest finding, the researchers have offered a detailed genetic analysis of 259 mycobacterium tuberculosis strains that were collected from different parts of the world. Their genome comparison clearly revealed that TB mycobacteria originated nearly 70,000 years ago in Africa.

The modern human's migratory behavior accompanied with various alterations in lifestyle produced  favorable condition for the deadly disease to evolve and spread. This kept TB alive during the early years.

 "We see that the diversity of tuberculosis bacteria has increased markedly when human populations expanded," evolutionary biologist Sebastien Gagneux said in a statement.

The researchers now plan to use the genetic data to study the activation and deactivation mechanism of TB, said Inaka Comas, lead author of the research.

TB is one of the world's deadliest diseases and nearly one third of the world population is infected with this disease. In 2011, 9 million people around the world were infected with TB and 1.4 million deaths were TB related. It is a leading killer among people who are infected with HIV.