Evolution of human tuberculosis: a systematic review and meta-analysis of paleopathological evidence.

Tuberculosis is a re-emerging disease and is a major problem in both developing and developed countries today. An estimated one third of the world's population is infected and almost two million people die from the disease each year. Bone lesions occur in 3-5% of active tuberculosis cases and can be used to diagnose the disease in ancient skeletal remains. A meta-analysis was conducted on 531 palaeopathological tuberculosis cases from 221 sites (7250 BCE to 1899) on all continents for the purpose of testing two hypotheses; (1) the frequency of bone lesions does not change through time and (2) the distribution of lesions throughout the skeleton does not change over time. The frequency of bone lesions was found to significantly decrease over time (P<0.05). The distribution of bone lesions was found to change from mainly spinal in earlier time periods to include more cases in other regions of the skeleton (long bones, joints, hands, feet) in later time periods. This difference in distribution was evaluated using a Chi-squared test and found to be significant (P<0.01). These findings are an important addition to the current knowledge of the evolution of the disease and the Mycobacterium tuberculosis.