The paleopathological evidence on the origins of human tuberculosis: a review

Tuberculosis (TB) has been one of the most important infectious diseases affecting mankind and still represents a plague on a global scale. In this narrative review the origins of tuberculosis are outlined, according to the evidence of paleopathology. In particular the first cases of human TB in ancient skeletal remains are presented, together with the most recent discoveries resulting from the paleomicrobiology of the tubercle bacillus, which provide innovative information on the history of TB. The paleopathological evidence of TB attests the presence of the disease starting from Neolithic times. Traditionally, it was thought that TB has a zoonotic origin, being acquired by humans from cattle during the Neolithic revolution. However, the biomolecular studies proposed a new evolutionary scenario demonstrating that human TB has a human origin. The researches show that the disease was present in the early human populations of Africa at least 70000 years ago and that it expanded following the migrations of Homo sapiens out of Africa, adapting to the different human groups. The demographic success of TB during the Neolithic period was due to the growth of density and size of the human host population, and not the zoonotic transfer from cattle, as previously hypothesized. These data demonstrate a long coevolution of the disease and its human host. Understanding the changes of TB through time thanks to the advances in the field of paleopathology can help to solve the present problems and understand the future evolution of TB.