The English, Germans and Italians called it “the French disease”. The Poles nicknamed it “the German disease,” while the Russians attributed it to the Poles. In France, it was called “Neapolitan disease” after the French army was infected during the invasion of Naples, Italy, in the first documented syphilis epidemic.
The origins of syphilis – a sexually transmitted infection (STI) that ravaged Europe in the 15th century and is still prevalent today – have remained unclear, difficult to study and the subject of debate.
A long-standing theory suggests that the disease emerged in the Americas and migrated to Europe after expeditions led by Christopher Columbus returned from the “New World.” However, a new study suggests the real story is more complicated.
Genetic information about ancient pathogens can be preserved in bones, dental plates, mummified bodies and historical medical specimens, extracted and studied – a field known as paleopathology.
A survey published on Wednesday (24) in periodical Nature used paleopathology techniques on 2,000-year-old bones unearthed in Brazil, with the aim of shedding more light on when and where syphilis originated. The study resulted in the recovery of the oldest known genomic evidence of Treponema palliduma bacterium that causes syphilis and other related diseases, dating back to long before the first transatlantic contacts.
“This study is incredibly exciting because it is the first truly ancient treponemal DNA that has been recovered from human archaeological remains that are more than a few hundred years old,” said Brenda J. Baker, a professor of anthropology at Arizona State University who has not was involved in the study.
A complex disease caused by a complex bacteria
Without treatment, syphilis can cause physical deformities, blindness and mental impairment. As a sexually transmitted infection, the condition has always carried a stigma, and so there have been past attempts by different populations to blame outbreaks on neighboring groups or countries.
It is particularly complex to study both the disease and the pathogen responsible for syphilis, according to Molly Zuckerman, professor and co-director of the New and Old World Bioarchaeology Laboratories at Mississippi State University, who was not involved in the research.
“It was only in 2017 that researchers managed to cultivate the T. pallidum for the first time, even though we have known it is the cause of syphilis for over a hundred years,” Zuckerman said in an email. “It is still expensive and complicated to study it in the laboratory. There are many reasons why, despite our best efforts, syphilis is one of the least understood common bacterial infections.”
The temporality and sudden onset of the first documented syphilis epidemic at the end of the 15th century have led many historians to conclude that it arrived in Europe after Columbus's expeditions. Others believe that bacteria T. pallidum have always had a global distribution, but perhaps became more virulent after initially manifesting as a mild disease.
“It is very clear that Europeans brought several diseases (including smallpox) to the New World, decimating native populations, so the hypothesis that the New World 'gave Europe syphilis' was attractive to some,” noted Sheila A. Lukehart, professor emeritus in the department of medicine, infectious diseases and global health at the University of Washington, who was not involved in the study.
Syphilis is closely related to, but different from, two other subspecies or lineages of non-sexually transmitted treponemal diseases, which have similar symptoms and are known as bejel and yaws, which were also the focus of the new research.
The team behind the new study examined 99 bones from the archaeological site known as Jabuticabeira II, in the Laguna region of Santa Catarina, on the Brazilian coast. Some bones showed characteristic signs of infection by T. pallidum – the bacteria effectively corrode the bones, leaving concave lesions.
Bone samples from four people provided enough genetic data for the team to analyze. One of them produced what study author Verena Schünemann, an assistant professor at the Institute for Evolutionary Medicine at the University of Zurich, described as a “high-coverage genome” with enough detail for refined analysis.
The analysis revealed that the pathogen responsible for the lesions was most closely related to the modern subspecies of T. pallidium that causes bejel, a disease found today in arid regions of Africa and the Middle East, with symptoms similar to syphilis.
The discovery strengthens previous suggestions that civilizations in the Americas experienced treponemal infections in pre-Columbian times, and that treponemal disease was already present in the New World at least 500 years before Columbus left.
Revelations of a bacterial family tree
Schünemann said the new findings do not mean that venereal syphilis, which caused the 15th-century epidemic, arrived in Europe from the Americas in the time of Columbus. One similar study previously conducted by his team found bacteria T. pallidum in human remains in Finland, Estonia, and the Netherlands from the early modern period (early 1400s), suggesting that some forms of treponemal disease, if not syphilis, were already circulating on the continent at the time of Columbus' expeditions to the New World.
Furthermore, the genome recovered from the Brazilian sample provided a bacterial family tree dating back thousands of years, suggesting that bacteria T. pallidum evolved to infect humans at least 12,000 years ago. Schünemann said it is possible that the bacteria could have been brought to the Americas by its first inhabitants who crossed the continent from Asia.
“I believe the story is much more complex than the Colombian hypothesis could have imagined,” she said.
Mathew Beale, senior scientist in bacterial evolutionary genomics at the Institute Wellcome Sangernear Cambridge, England, agreed with Schünemann's assessment, stating, via email, that the study does not “prove or disprove the central tenet of the Colombian hypothesis itself – that Columbus' voyage led to the importation of Treponema and resulted in the outbreaks of the 1500s and then modern syphilis.”
“This is mainly because the bacteria sequenced is not a direct ancestor of the strain that causes modern syphilis. (…) It is a sister species. This could mean that the various treponematoses were already very widely spread around the world, and could even precede the ancient migration and settlement of the Americas,” said Beale, who was not involved in the research.
“This could alternatively mean that many different treponematoses were present in the New World and one of them, distant from the ancient genomes in this article, was in fact imported by Columbus and his peers,” he added.
Additional research into ancient genomes from around the world may be able to solve the mystery, illuminating which subspecies of the bacteria were present in Europe and the New World before Columbus's voyages, according to Lukehart.
“The biggest scientific question now is not about syphilis, but about the distribution of the three subspecies around the globe, especially in pre-Columbian samples,” Lukehart said.
“The modern tools available to extract DNA from ancient samples, to enrich treponemal DNA, and to obtain deep sequencing of samples have rapidly increased our understanding of the Treponema.”
Source: CNN Brasil
I am an experienced journalist and writer with a career in the news industry. My focus is on covering Top News stories for World Stock Market, where I provide comprehensive analysis and commentary on markets around the world. I have expertise in writing both long-form articles and shorter pieces that deliver timely, relevant updates to readers.
