Paleopathology of human tuberculosis and the potential role of climate

Abstract

Both origin and evolution of tuberculosis and its pathogens (Mycobacterium tuberculosis complex) are not fully understood. The paleopathological investigation of human remains offers a unique insight into the molecular evolution and spread including correlative data of the environment. The molecular analysis of material from Egypt (3000-500 BC), Sudan (200-600 AD), Hungary (600-1700 AD), Latvia (1200-1600 AD), and South Germany (1400-1800 AD) urprisingly revealed constantly high frequencies of tuberculosis in all different time periods excluding significant environmental influence on tuberculosis spread. The typing of various mycobacteria strains provides evidence for ancestral M. tuberculosis strains in Pre- to early Egyptian dynastic material (3500-2650 BC), while typical M. africanum signatures were detected in a Middle Kingdom tomb (2050-1650 BC). Samples from the New Kingdom to Late Period (1500-500 BC) indicated modern M. tuberculosis strains. No evidence was seen for M. bovis in Egyptian material while M. bovis signatures were first identified in Siberian biomaterial dating 2000 years before present. These results contraindicates the theory that M. tuberculosis evolved from M. bovis during early domestication in the region of the "Fertile Crescent," but supports the scenario that M. tuberculosis probably derived from an ancestral progenitor strain. The environmental influence of this evolutionary scenario deserves continuing intense evaluation.

Figure 1

Schematic diagram of the potential evolution of the various tuberculosis strains (modified according to Brosch et al. [3]) and its impact on ancient Egyptian findings. The circles indicate the presumed location of the TB main strains as identified by spoligotyping and typical mutations in the various ancient Egyptian populations.

Figure 2

Typical macrophology of spinal tuberculosis with (a) ventral destruction of the affected vertebral bodies and (b) fistular defects of the bone.

Figure 3

Macromorphology of nonsepcific pathological alteration of the ventral side of the vertebral body, which is still suggestive for a very early phase of osseous tuberculosis.