Tuberculosis infection in a late-medieval Hungarian population

The AD 16-17(th) century skeletal series from Bácsalmás-Óalmás (southern Hungary) has already been the subject of previous paleopathological studies concerning TB-related bone lesions. Due to recent development of macroscopic and molecular diagnostic methods in paleopathology and paleomicrobiology, a five-year international research program was recently started in order to re-evaluate the TB-related lesions in the complete series, comprising 481 skeletons. The skeletal material of these individuals was examined using macromorphological methods focusing on both classical/advanced stage skeletal TB alterations and atypical/early-stage TB lesions. Paleomicrobial analysis was used to study the presence of Mycobacterium tuberculosis complex (MTBC) DNA both in morphologically positive and negative cases. Samples were tested for the repetitive element IS6110 and further characterized by spoligotyping. In the whole series, 283 possible cases of TB infections were identified based on morphological alterations. Skeletal samples of eighteen individuals, morphologically positive as well as negative cases, were selected for further biomolecular examinations. Among them, seven individuals were PCR positive for the repetitive IS6110 sequence of the MTBC genome. Compared to the few cases of TB from the Bácsalmás-Óalmás series previously described, a much higher prevalence of MTBC infected skeletons was revealed in this study. The atypical/early stage skeletal lesions occurred significantly more frequently than the so-called classical alterations. Paleomicrobial analysis confirmed a prevalence of MTBC infection nearing 40% among the selected sample. Preliminary results also indicated better preservation of bacterial DNA in the compact layer of long bones and teeth, while spoligotyping suggested infection by different MTBC pathogens.