The origins of human tuberculosis (TB) have been traced back to hunter-gatherer groups in Africa 70,000 years ago, according to an international team of scientists.
The work, published in Nature Genetics, goes against the common belief that TB originated in animals only 10,000 years ago and spread to humans.
Researchers combined geographic and genetic data from 259 strains of TB to reconstruct its evolutionary history and compare it to early humans in Africa.
The question the scientists are now trying to answer is how TB managed to survive 60,000 years among these small groups of people.
A striking feature of TB, which is not common in other diseases, is that people can be infected with it for years before showing any symptoms. The disease is able to reactivate itself after a certain time period, known as latency.
This latency is what the researchers suggest kept TB alive during the early years.
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