The BRICS TimesDNA evidence from soldiers’ teeth reveals bacterial infections that likely compounded the disastrous 1812 withdrawal.
In 1812, Emperor Napoleon Bonaparte led his army on a doomed and disastrous Russian retreat. Hundreds of thousands of soldiers died as food became scarce. The harsh winter approached and diseases spread rapidly through the ranks. Scientists have now identified microbes potentially contributing to their collapse.
Bacteria Found in Teeth
Ancient DNA was taken from the teeth of Napoleonic soldiers. This DNA revealed two species of fever-causing bacteria. Geneticist Nicolás Rascovan of the Institut Pasteur in Paris shared this with his team. Their findings were reported on October 24 in Current Biology. Historians have long suggested the soldiers lived and died in a teeming pool of infectious diseases.
These findings match eyewitness accounts from over 200 years ago. Rafe Blaufarb is a historian specializing in Napoleonic history. Doctors back then recorded soldiers’ symptoms accurately. These included fever, diarrhea, pneumonia, and other signs of bacterial infection. The new study identified two bacteria types. They were not previously linked to the deadly retreat. Blaufarb, from Florida State University, says this adds “DNA-level biological details to the story.”
The Grinding Retreat
Napoleon’s ill-fated Russian invasion started quite successfully. The military leader had gathered over half a million troops. He had already conquered a large part of Europe. But the army reached Moscow to find a burned and abandoned city. The Russians had torched the city. Then the brutal winter began to set in.
Retreat was the only option left, according to Blaufarb. The army began a grueling march out of Russia. It was bitterly cold with very little food. There is little debate about the cause of so many deaths. Subzero temperatures, lack of food, and exhaustion were rampant. Walking hundreds of kilometers through ice and snow was deadly. “Any of this could kill you,” he notes. “It’s just a bad, bad, bad scene. It’s as bad as it can be.”
New Pathogens Revealed
Illnesses also seriously affected the troops. In 2006, DNA evidence confirmed bacteria causing typhus and trench fever. This was found in the remains of Napoleonic soldiers. This matched historical records well. However, in that first analysis, scientists only searched for those two specific bacteria. They didn’t look for others that may have been present.
The new research utilized a different method. “We went and searched for any known pathogen,” Rascovan explained. Their technique is called shotgun sequencing. It captures many small DNA fragments in a sample. This includes DNA from the soldiers’ bodies. It also includes bacteria that may have infected them. Even soil microbes living nearby are captured. It’s like fishing with a giant net instead of a rod.
Researchers analyzed the teeth of 13 soldiers. They were buried in a mass grave in Lithuania. The scientists found a type of Salmonella enterica in four soldiers. This bacteria causes paratyphoid fever. The team found evidence of the louse-borne Borrelia recurrentis in two soldiers. This bacteria is responsible for relapsing fever.
Rascovan stressed that they only studied a tiny fraction of the deceased soldiers. Hundreds of thousands perished. Therefore, judging the infection’s spread is impossible. “By no means are we trying to say that these two pathogens were a major cause of death in this army,” he asserted. But combined with cold and hunger, these pathogens likely worsened the soldiers’ downfall.
As Blaufarb summarized: “The real mystery is how any of them got out at all.”
