DNA analysis of soldiers' remains reveals bacterial causes differing from historical accounts

In the summer of 1812, French Emperor Napoleon Bonaparte led approximately 500,000 soldiers on a campaign to conquer Russia but suffered a devastating defeat. It is widely reported that a significant portion of the French army perished that winter. For decades, historians have attributed the collapse of Napoleon's forces to starvation, cold, and infectious diseases such as typhus. However, a recent study has challenged this long-held belief.

According to international journals Nature and The New York Times, a research team led by Nicolas Rascovan, head of the microbial genomics group at France's Pasteur Institute, published their findings in the journal Current Biology on the 24th of last month. The team analyzed DNA extracted from the remains of 13 French soldiers discovered in a mass grave in Vilnius, Lithuania -- a key retreat route during the French army's withdrawal from Russia. Using advanced technology to extract and sequence DNA from ancient teeth, the researchers identified two bacterial species: Salmonella enterica and Borrelia recurrentis, which cause typhoid fever and relapsing fever, respectively. Notably, the bacteria responsible for typhus were absent.

This suggests that Napoleon's troops may have succumbed to typhoid fever or relapsing fever rather than typhus. Typhoid fever is characterized by high fever and abdominal pain, while relapsing fever involves recurring cycles of high temperatures (39-40°C) followed by remission. The soldiers, malnourished, unable to maintain hygiene, and exposed to extreme cold, likely faced a deadly combination of these factors and infectious diseases.

The study also revealed that the Borrelia strain causing relapsing fever matched a lineage present in Britain during the Iron Age, approximately 2,000 years ago. This indicates the bacterium's survival in Europe over millennia, offering critical insights into the evolutionary history of infectious diseases.

Napoleon's Army Collapsed From Typhoid, Relapsing Fever, Study Finds