DNA reveals the diseases that devastated Napoleon's doomed army

When Napoleon marched into Russia in 1812, he brought with him the largest army Europe had ever seen.

When Napoleon marched into Russia in 1812, he brought with him the largest army Europe had ever seen. When he limped back out, he’d met his match — not in muskets or cannon fire, but in microbes.

Researchers who analyzed DNA from the teeth of soldiers who died during the retreat from Moscow say they have identified two diseases that devastated the emperor’s vaunted Grande Armée.

Ever since 1812, “people have thought that typhus was the most prevalent disease in the army,” said Nicolás Rascovan, the head of the microbial paleogenomics unit at the Institut Pasteur and an author of the study, published in the journal Current Biology.

Using a technique called shotgun sequencing, Rascovan and his team were able to analyze ancient DNA from the dental remains of 13 soldiers found near Vilnius, Lithuania, and identify two “previously undocumented pathogens.”

“We confirmed the presence of Salmonella enterica belonging to the Paratyphi C lineage,” he told NBC News, referring to the bacteria responsible for paratyphoid fever, as well as “Borrelia recurrentis, the bacteria responsible for relapsing fever,” which causes episodes of fever.