3,500-year-old skeletons challenge what scientists thought they knew about syphilis

A groundbreaking study led by Dr. Melandri Vlok from Charles Sturt University and an international team of researchers has uncovered new evidence that challenges long-held beliefs about the transmission of ancient diseases, specifically treponemal diseases such as syphilis and yaws. The research, published in the International Journal of Osteoarchaeology, analyzed skeletal remains from prehistoric Vietnam, dating back 4,000 to 3,200 years ago, revealing that these diseases could have been passed from mother to child thousands of years ago.

Historically, congenital transmission has been viewed as a strong indicator of venereal syphilis, but this new study suggests that other forms of treponemal disease may also spread this way. The team examined 309 individuals from 16 archaeological sites in Vietnam, focusing on three children whose teeth and bones showed clear signs of congenital treponematosis.

While the overall pattern of infection points away from venereal syphilis, the findings indicate that nonvenereal treponemal diseases like yaws may be more common than previously thought. This discovery has significant implications for understanding the origin of syphilis, as it challenges the assumption that congenital infection is a definitive sign of venereal syphilis.

The research also highlights the challenges in studying ancient infectious diseases, particularly in tropical regions where ancient DNA is poorly preserved and ethical concerns arise regarding destructive sampling. The findings emphasize the complex history of treponemal diseases and the need to reconsider how we interpret skeletal evidence in understanding past epidemics.