Bluesman Commentary

Genetic Study Bolsters Columbus Link to Syphilis

Published: January 15, 2008 NY Times – Science

In her investigation, Ms. Harper studied 22 human Treponemal pallidum strains. The DNA in their genes was sequenced in nearly all cases, examined for changes and eventually used in constructing phylogenetic trees incorporating all variations in the strains. 

An Old World yaws subspecies was found to occupy the base of the tree, indicating its ancestral position in the treponemal family, she said. The terminal position of the venereal syphilis subspecies on the tree showed it had diverged most recently from the rest of the bacterial family.  Specimens from two Guyana yaws cases were included in the study, after they were collected and processed by Dr. Silverman. Genetic analysis showed that this yaws strain was the closest known relative to venereal syphilis. 

Ms. Harper’s team concluded that New World yaws belonged to a group distinct from Old World strains, thus occupying the place on the tree more likely to be intermediate between the nonvenereal strains previously existing in Europe and the one for modern syphilis.  If this seemed to solidify the Columbus hypothesis, the researchers cautioned that a “transfer agent between humans and nonhuman primates cannot be ruled out using the available genetic data.” 

Dr. Armelagos said research into the origins of syphilis would continue, because “understanding its evolution is important not just for biology, but for understanding social and political history.”  Noting that the disease was a major killer in Renaissance Europe, he said, “It could be argued that syphilis is one of the important early examples of globalization and disease, and globalization remains an important factor in emerging diseases.”