Researchers have uncovered new DNA evidence that challenges established theories regarding Napoleon’s ill-fated 1812 invasion of Russia. As his Grand Army, comprising around 500,000 soldiers, advanced toward Moscow, it encountered severe resistance, dwindling resources, and the harshness of winter.

As the troops began their retreat, starvation and disease were rampant. Analyzing the remains of soldiers now indicates that multiple infectious diseases may have caused the significant loss of life in the French emperor’s army, rather than typhus being the singular primary cause of devastation.

A recent study led by Dr. Nicholas Raskovan at the Pasteur Institute in Paris involved extracting genetic material from the teeth of 13 soldiers interred in a mass grave in Vilnius, Lithuania.

Through ancient DNA sequencing, no evidence of typhus was identified. Instead of the long-suspected bacteria rickettsia, the team pinpointed two distinct pathogens: salmonella enterica, which causes enteric fever (like typhoid), and Borrelia recurrentis, linked to recurring fever.

Raskovan mentioned, “Our research alters the understanding of pathogens previously unrecognized,” as reported in BBC Science Focus.

Previous research employed PCR tests, akin to those used in contemporary COVID-19 testing, to search solely for specific microorganisms. Currently available technology enables scientists to “cast a wider net,” allowing them to detect DNA fragments from all microorganisms present, Raskovan explained.

“Thanks to advancements in technology, we now have insights that were unimaginable a decade ago,” Raskovan noted.

“When we integrate our prior and current research, we discover that four different diseases affected just a small group of individuals. This implies that a single pathogen didn’t account for all the 3,000 deaths, but rather, these individuals were infected with various pathogens.”

In essence, the situation for Napoleon’s army during their retreat from Russia was dire, facilitating the spread of various diseases. It was almost inevitable that if one illness was avoided, another would take hold.

The research also highlighted the strain Borrelia recurrentis found at the site, which is genetically identical to those from Iron Age Britain, approximately 2,000 years ago, a lineage that has since vanished.

Raskovan stated, “This strain derives from an ancestor that either no longer exists or is currently unknown. This emphasizes the significant changes in sanitation over the past two centuries, particularly with the advent of antibiotics that have virtually eradicated this once prevalent disease.”

For Raskovan, these ancient microorganisms are more than peculiar findings; they are historical witnesses. “For those infected, it’s not surprising,” he remarked. “For me, it’s fulfilling to reconstruct history.”

“These pathogens provide us with a means to learn about past populations and their dynamics.”

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