A team of researchers has made significant progress in addressing a long-standing debate: was syphilis brought to Europe from the Americas at the end of the 15th century, or had it always existed there? Genomic analysis of ancient pathogens from skeletons that date back before 1492 supports the idea of an introduction from the Americas, yet the global spread of the disease remains a dark chapter from the colonial era.
A team from the Max Planck Institute for Evolutionary Anthropology has made vital strides in settling a long-source of contention — was syphilis introduced to Europe from the Americas near the close of the 15th century, or had it always been present? Genomic analysis of ancient pathogens from bones predating 1492 substantiates its arrival from the Americas; however, the resulting global proliferation is a noteworthy consequence of the colonial period.
In the spring of 1495, the Italian campaign led by Charles VIII of France faced disruption due to a severe outbreak of an unfamiliar illness, marked by high mortality rates that swiftly spread across Europe, leaving many of its survivors with significant physical and mental impairments. This documented epidemic is now viewed as the first historical evidence of syphilis.
The origins of syphilis have been debated for decades. The outbreak in the late 15th century came shortly after Columbus’ return from his initial voyages to the Americas, which led some to speculate that contact with these new lands and peoples may have triggered the sudden emergence of the disease. While numerous communicable illnesses traveled from Europe to the Americas in the early colonial age, causing devastation among indigenous populations, syphilis is among the rare diseases believed to have possibly originated in the opposite direction. The “Columbian theory” regarding syphilis has gained traction over time, yet it still faces skepticism. The theory begins to lose coherence when experts examine the skeletal lesions found in Medieval European remains. Individuals suffering from long-term infections, as well as those born with it, often exhibit bone or dental changes. In recent decades, numerous skeletons from Europe that predate 1492 have been discovered. Many scholars now suggest that the history of syphilis in Europe predates Columbus’s arrival, with the pandemic of the late 15th century occurring due to reasons unrelated to new contacts. However, neither theory has been conclusively verified.
Examining five ancient pathogen genomes
Retrieving pathogen DNA from archaeological bones has the potential to provide critical insights that may favor one theory over the other. Such analyses have significantly expanded our understanding of the historical trajectories of diseases like plague, tuberculosis, leprosy, and smallpox. However, tracing the history of syphilis has proven to be more complex. “While we have reconstructed genomes from the syphilis family from ancient remains, these have not resolved pivotal questions regarding the pre- or post-Columbian associations with syphilis,” says Kirsten Bos, leader of the molecular paleopathology group at the Max Planck Institute for Evolutionary Anthropology.
A new study, spearheaded by Bos and Johannes Krause, the director of the Department of Archaeogenetics at the Max Planck Institute in Leipzig, marks a significant advancement toward shedding light on this debate. Collaborating with scientists and archaeologists from several countries in the Americas, the study examined archaeological bones from these regions, which showed infection patterns resembling syphilis from ancient times. “We have long recognized that syphilis-like infections existed in the Americas for thousands of years, but it’s impossible to fully characterize the disease solely based on lesions,” notes Casey Kirkpatrick, a postdoctoral researcher and paleopathologist involved in the research. Bone pathology leaves uncertainties regarding whether the disease originated in the Americas or if it traveled from Asia deep into our past alongside early human migrations to the Americas around 15,000 years ago.
Using advanced techniques, the research team successfully recovered and analyzed five ancient genomes belonging to the syphilis disease family from Mexico, Chile, Peru, and Argentina. Computational microbiologist and postdoctoral researcher Lesley Sitter tackled the task of deciphering these ancient genetic puzzles, stating, “Although preservation posed some challenges for our analyses, we were able to reliably outline the relationships among these extinct variants and the strains that affect global health today.”
Syphilis and its related diseases existed in the Americas before “Columbus”
Syphilis belongs to a small group of diseases that also includes yaws and bejel, both recognized as neglected tropical diseases found in equatorial regions worldwide. Postdoctoral researcher Rodrigo Barquera, who previously worked with archaeological remains from colonial Mexico, confirmed the presence of both syphilis and yaws in Mexico City as early as the 17th century. Drawing upon the newest ancient genomic information, it is evident that the Americas were a center for the historical diversity of this disease group well before Columbus’s arrival. “We have identified extinct relatives of all known forms of this disease family, implying that syphilis, yaws, and bejel are modern descendants of pathogens that were present in the Americas,” asserts Barquera.
“The data clearly indicate that syphilis and its relatives originated in the Americas, and their introduction to Europe starting in the late 15th century aligns well with this evidence,” Bos adds. Following this period, there appears to have been a surge in syphilis and yaws cases around AD 1500. This spike likely fueled the widespread and severe outbreak of the 16th century in Europe, which was driven by human trafficking networks and European expansions across the Americas and Africa in subsequent decades and centuries. “While early forms of these diseases existed among indigenous American peoples, it was Europeans who played a crucial role in disseminating them globally,” she concludes.
With strong evidence suggesting an American origin for syphilis, how do we reconcile this with the claims of syphilis-like bone lesions identified in pre-1492 Europe? “The quest will persist to define these earlier forms, and ancient DNA will undoubtedly be a valuable asset,” Krause comments. “It remains to be seen what older related diseases may have spread around the globe through humans or other animals before the emergence of the syphilis family.”
