When Napoleon marched into Russia in 1812, he brought with him the largest army Europe had ever seen. When he limped back out, he had 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.
Since 1812, “people have thought that typhus was the most common disease in the military,” says Nicolás Rascovan, head of the microbial paleogenomics unit at the Institut Pasteur and 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 have confirmed the presence of Salmonella enterica belonging to the Paratyphi C lineage,” he told NBC News, referring to the bacterium responsible for paratyphoid fever, as well as “Borrelia recurrentis, the bacterium responsible for relapsing fever,” which causes fever attacks.
These diseases would have thrived where people were “under very poor sanitary conditions or hygiene,” he added.
The findings fit historical descriptions of the symptoms experienced by soldiers in Napoleon’s army, such as fever and diarrhea, the researchers said in the study.
A “reasonable scenario” for the deaths would be a “combination of fatigue, cold and various illnesses, including paratyphoid fever and lice-borne relapsing fever,” they wrote.
“While not necessarily fatal, louse-borne relapsing fever can significantly weaken an already exhausted individual,” she added.
Unlike a 2006 study that found traces of the bacteria that cause typhoid or trench fever in four people in a group of 35, the team found no traces of these diseases.
But Rascovan said that while the earlier research was limited by the technology of the time, its results remained valid and, when combined with the new findings, provided a better picture of the conditions that devastated Napoleon’s army.
“Finding four different pathogens in such a number of individuals really shows that there was a high prevalence of all kinds of infectious diseases,” he said.
By the time Napoleon’s forces withdrew, an estimated 300,000 men had been killed. Not even an emperor, it seems, can outsmart a microbe.
This article was originally published on NBCNews.com
