PhD Dissertations: Andrew Hickok, 2013

Palaeopathological and Palaeoepidemiological Analyses of
Treponemal Infection on the Northwest Coast:
A Unitarian Perspective


Bone and dental lesions characteristic of treponemal infection have been reported in the skeletal remains of indigenous peoples from a number of archaeological sites on the Northwest Coast.  Associated radiocarbon dates and material culture indicate that some cases are over 3000 years old.  The evidence identified to date includes diagnostic lesions indicative of the venereal treponemal syndrome, venereal syphilis.  This dissertation reviews the previously reported evidence and introduces new possible cases of treponematosis from recent archaeological findings in my work as a consulting bioarchaeologist, synthesizing these data to illuminate patterns of prevalence and distribution of treponemal skeletal lesions in time and space to evaluate the treponemal syndrome obtained on the Northwest Coast.  A novel system of diagnosing cases of treponemal infection by the composite scores of different lesion types to produce a rigorous and repeatable diagnostic index (Treponemal Index) is introduced and applied to 55 cases identified as possible treponematosis from archaeological populations.

In addition to caries sicca and gummatous osteomyelitis, evidence of congenital syphilis, aortitis and neroarthropathy are found, confirming that a venereal treponemal syndrome was present in archaeological populations of the Strait of Georgia region.  The prevalence of cases peaks in the Middle Period, and may have contributed to the decline observed in the Late Period in the archaeological record of the Strait of Georgia through the impact on fertility from congenital infection.

Longstanding debates about the nature and origin of venereal syphilis and the other human treponemes continue into the 21st century.  However, since the subsuming of endemic syphilis and yaws as subspecies of Treponema pallidum, the Unitarian Hypothesis has by definition been confirmed.  This dissertation embraces this perspective.  The data generated here are subsequently employed to test the predictions and principles of the Unitarian model against the Northwest Coast archaeological and ethnographic record.

Keywords:        Treponemal infection; syphilis; Unitarian Hypothesis; bioarchaeology; Northwest Coast archaeology; post-Marpole decline