Two cases of leprosy from Žatec (Bohemia), dated to the turn of the 12th century and confirmed by DNA analysis for Mycobacterium leprae

The leprosy known today primarily from tropical areas was a relatively common disease in European Middle Ages. This article describes two skeletons bearing palaeopathological indications of leprosy from a cemetery at Žatec in North-West Bohemia (Czech Republic). The archaeological context clearly shows that these individuals were buried prior to the second decade of the 12th century, and most probably in the second half of 11th century. This rules out the possibility that these individuals might have contracted the disease in connection with the Crusades, in which a Bohemian contingent under Prince Vladislav II participated from 1141 to 1142. Molecular genetic methods were applied to detect specific DNA fragments of the causative agent of leprosy, Mycobacterium leprae. The nasal concha of one individual yielded DNA that could be directly sequenced after isolation and amplification. The vertebral body of the second individual, on the other hand, did not provide DNA of sufficient quality for direct sequencing and only weak amplification was detectable. The morphological and genetic analyses both indicate that leprosy existed prior to the Crusades in medieval Bohemia, albeit that its prevalence was probably not as great as in northern or western Europe.