Did Columbus and his men introduce the syphilis pathogen into Renaissance Europe after contracting it during their voyage to the New World? Or does syphilis have a much longer history in the Old World? The most comprehensive comparative genetic analysis conducted on the family of bacteria (the treponemes) that cause syphilis and related diseases such as yaws, published Tuesday, January 15 in PLoS Neglected Tropical Diseases, supports the so-called “Columbian theory” of syphilis’s origins.
Kristin Harper (Emory University, Atlanta, USA) approached this centuries-old debate by using phylogenetics — the study of the evolutionary relatedness between organisms — to study 26 geographically disparate strains of treponemes. The venereal syphilis-causing strains originated most recently, and their closest relatives were strains collected in South America that cause the treponemal disease yaws.
“That supports the hypothesis that syphilis — or some progenitor — came from the New World,” Harper says.
While it is generally agreed that the first recorded epidemic of syphilis occurred in Europe in 1495, controversy has raged ever since over the origin of the pathogen. Most of the evidence in recent years has come from bones of past civilizations in both New World and Old World sites, since chronic syphilis causes skeletal lesions. In many cases, however, skeletal analysis is inconclusive, due to problems with pinpointing the age of the bones and the lack of supporting epidemiological evidence.
Further complicating the research is the fact that the family of Treponema bacteria causes different diseases that share some symptoms but have different modes of transmission. Syphilis is sexually transmitted, but yaws and endemic syphilis are tropical diseases that are transmitted through skin-to-skin or oral contact. One hypothesis is that a subspecies of Treponema from the warm, moist climate of the tropical New World mutated into the venereal, syphilis-causing subspecies to survive in the cooler and relatively more hygienic European environment.
The phylogenetic analysis indicated that yaws is an ancient infection in humans while venereal syphilis arose relatively recently. The study results are especially significant due to the large number of different strains analyzed, including two never-before-sequenced strains of yaws from isolated inhabitants of Guyana's interior. At Harper's request, the Guyana samples were collected during a medical mission by Ve’ahavta, the Canadian Jewish Humanitarian and Relief Committee.
“Syphilis was a major killer in Europe during the Renaissance,” says co-author George Armelagos, a skeletal biologist whose research put him at the forefront of the syphilis debate 30 years ago. “Understanding its evolution is important not just for biology, but for understanding social and political history. 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.”
CITATION: Harper KN, Ocampo PS, Steiner BM, George RW, Silverman MS, et al. (2008) On the Origin of the Treponematoses: A Phylogenetic Approach. PLoS Negl Trop Dis 2(1): e148. doi:10.1371/journal.pntd.0000148
CONTACT:
Kristen Harper
Emory University
Population Biology, Ecology, and Evolution
207 Anthropology Building
1557 Dickey Dr.
Atlanta, GA 30322
United States of America
314 550-5191
knharpe@emory.edu
Beverly Cox Clark
Associate Director, Emory University Media Relations
404-712-8780
404-275-4771 (cell)
Disclaimer
This press release refers to an upcoming article in PLoS Neglected Tropical Diseases. The release is provided by journal staff. Any opinions expressed in these releases or articles are the personal views of the journal staff and/or article contributors, and do not necessarily represent the views or policies of PLoS. PLoS expressly disclaims any and all warranties and liability in connection with the information found in the releases and articles and your use of such information.
About PLoS Neglected Tropical Diseases
PLoS Neglected Tropical Diseases (http://www.plosntds.org/) is a peer-reviewed, open-access journal devoted to the pathology, epidemiology, prevention, treatment, and control of the neglected tropical diseases, as well as public policy relevant to this group of diseases. All works published in PLoS Neglected Tropical Diseases are open access, which means that everything is immediately and freely available subject only to the condition that the original authorship and source are properly attributed. The Public Library of Science uses the Creative Commons Attribution License, and copyright is retained by the authors.
About the Public Library of Science
The Public Library of Science (PLoS) is a non-profit organization of scientists and physicians committed to making the world's scientific and medical literature a freely available public resource. For more information, visit http://www.plos.org.
PLEASE MENTION THE OPEN-ACCESS JOURNAL PLoS NEGLECTED TROPICAL DISEASES (www.plosntds.org) AS THE SOURCE FOR THIS ARTICLE AND PROVIDE A LINK TO THE FREELY AVAILABLE TEXT. THANK YOU.
Journal
PLoS Neglected Tropical Diseases