Science: Napoleon's Russian Defeat? It Was All the Fault of Two Bacteria

Napoleon's soldiers who fought in the Russian campaign of 1812 were decimated by the spread of two pathogens, responsible for enteric fever and relapsing fever. This curious finding emerges from a study published in the journal Current Biology , conducted by scientists at the Institut Pasteur in France . The team, led by Nicolas Rascovan, extracted and sequenced genetic material from the teeth of 13 soldiers buried in a mass grave in Vilnius, Lithuania, and exhumed in 2002. After removing environmental contamination, the authors identified DNA fragments and bacterial pathogens. In the summer of 1812, experts explain, French Emperor Napoleon Bonaparte led approximately half a million soldiers across Russian territory with the aim of conquering the region. However, in December, only a small portion of the valiant army was still alive. Historical records point to hunger, cold, and the spread of typhus as the main causes of this resounding defeat. However, researchers have identified two pathogens known to cause enteric fever and relapsing fever, which may have contributed to the army's defeat. "It's truly exciting to use modern technology," says Rascovan, " to shed light on events from 200 years ago. For decades, typhus was thought to be the main reason for Napoleon's defeat. In fact, we identified traces of Salmonella enterica, a bacterium that causes enteric fever, and Borrelia recurrentis, associated with relapsing fever." Previous research had detected the presence of other pathogens, but the researchers hypothesize that the discrepancy is related to the sequencing method used. "DNA," explains Rascovan, "degrades significantly over time. Our method is capable of analyzing even very short sequences." The research team also discovered that the B. recurrentis found on Napoleon's soldiers belonged to the same lineage identified in ancient Britain 2,000 years earlier. "This strain," they conclude, "has persisted for millennia in Europe, even though all current pathogens analyzed so far belong to a different form. This work, in fact, provides valuable insights for better understanding and addressing infectious diseases today."