Tuberculosis in medieval Iceland: evidence from Hofstaðir, Keldudalur and Skeljastaðir.

As part of a larger research project, 274 skeletons from three medieval Icelandic sites were evaluated for signs of infectious disease and 32 were found to have lesions at least consistent with a diagnosis of tuberculosis (TB): eight non-adults ranging in age from infancy to up to 17 years of age, and 24 adults. A higher proportion of individuals from Skeljastaðir and Keldudalur were affected than at Hofstaðir, an observation which may be compatible with Hofstaðir's higher status. A higher number of male skeletons overall (n. 17) than female skeletons (n. 8) exhibited pathological change. The sample is unique for its high numbers of well-preserved infants, and the appearance of TB in children is indicative of continual transmission in a community. The changes recorded in infant remains are marked by destruction and minimal periosteal new bone formation, while one adult skeleton exhibits the classic sign of Pott's disease. Other signs on the skeletons include evidence for past lymphadenitis and iliopsoas (cold) abscess. These cases indicate that TB was likely introduced to Iceland soon after the settlement period and became endemic in different regions from at least the late 10^th - mid 13^th centuries.