Co–infection ofMycobacterium tuberculosisandMycobacterium lepraein human archaeological samples: a possible explanation for the historical decline of leprosy

Abstract

Both leprosy and tuberculosis were prevalent in Europe during the first millennium but thereafter leprosy declined. It is not known why this occurred, but one suggestion is that cross-immunity protected tuberculosis patients from leprosy. To investigate any relationship between the two diseases, selected archaeological samples, dating from the Roman period to the thirteenth century, were examined for both Mycobacterium leprae and Mycobacterium tuberculosis DNA, using PCR. The work was carried out and verified in geographically separate and independent laboratories. Several specimens with palaeopathological signs of leprosy were found to contain DNA from both pathogens, indicating that these diseases coexisted in the past. We suggest that the immunological changes found in multi-bacillary leprosy, in association with the socio-economic impact on those suffering from the disease, led to increased mortality from tuberculosis and therefore to the historical decline in leprosy.

Leprosy and Tuberculosis Co-Infection: Clinical and Immunological Report of Two Cases and Review of the Literature

“…Donoghue and others 20 demonstrated the presence of disseminated M. leprae and M. tuberculosis co-infection in human archaeological samples dating from the Roman period using polymerase chain reaction. They argued that the impaired cell-mediated response to M. leprae of lepromatous leprosy patients would favor the advance of the more virulent pathogen M. tuberculosis.…”

Co-Infection with M. tuberculosis and M. leprae-Case Report and Systematic Review

“…Recent analysis of bone material from human remains at sites in Israel, Egypt and Europe showed DNA traces of both M. tuberculosis and M. leprae infection in 42% of the samples. Since tuberculosis is a more aggressive illness than leprosy, the authors suggest that patients with tuberculosis and leprosy were more likely to have died faster, reducing the reservoir for M. leprae [26]. The relationship between the two mycobacterial diseases continues to be enigmatic despite decades of research.…”

Evaluating bacterial pathogen DNA preservation in museum osteological collections

“…However, a survey of the extensive ancient TB literature shows that while most positive identifications come from specimens with some sort of skeletal lesion, many of these samples are not from locations proximal to a lesion (e.g. Haas et al 2000;Donoghue et al 2005). On this evidence, we propose that the location of sampling is not critical, and that the recovered pathogen DNA must originally have been in the blood stream.…”

“…Recent reports have begun to incorporate these standards (Donoghue et al 2005;Taylor et al 2005), and demonstrate an increasing sophistication in approach.…”