Modern DNA Analysis Sheds Light on the Mystery of Napoleon’s Grande Armée’s Demise in 1812

لبنان اليوم

A recent study sheds light on the reasons for the collapse of the French army in Napoleon’s campaign on Russia in 1812.
Through the analysis of DNA extracted from the teeth of soldiers buried in mass graves near Vilnius (Lithuania), the study revealed the presence of two previously undocumented infections: Salmonella enterica, which causes paratyphoid fever, and Borrelia recurrentis, which causes louse-borne relapsing fever.
A team from the Pasteur Institute confirmed that “the plausible scenario for the death of these soldiers would be a combination of exhaustion, cold and several diseases, including paratyphoid fever and louse-borne relapsing fever.” The team noted that metagenomic analysis found no trace of “Rickettsia prowazekii” (typhus) or “Bartonella quintana” (trench fever).
The study, published in the journal “Current Biology” in 2025, analyzed 13 teeth and identified genetic material for Salmonella enterica serovar Paratyphi C in four individuals, and sequences matching Borrelia recurrentis in two others.
Lead author Nicolas Rascovan says: “It is extremely exciting to use the technology we have today to discover and diagnose something that has been buried for 200 years.” The researchers point out that relapsing fever is “not necessarily fatal, but it may significantly weaken an already exhausted person,” while not ruling out the presence of other pathogens.
These findings are consistent with contemporary medical accounts of the retreat; French army doctor J.R.L.D. de Kerckhove documented the prevalence of diarrhea and dysentery among soldiers in Lithuania, writing: “We came across, in almost every house, from Orsha to Wilna, large barrels of salted beets… We used to eat and drink its juice when thirsty, which caused us great discomfort and severely irritated the digestive system,” symptoms that mimic paratyphoid fever.
The study places the discovery in its historical context: the campaign that began with an army of about 600,000 men and ended with fewer than 30,000 returning alive, amid a devastating combination of exhaustion, hunger, cold, Russian and militia attacks, culminating in the bloody crossing of the Berezina. The authors warn of the limited sample size, stressing that “analyzing a larger number of samples will be necessary to fully understand the range of epidemic diseases that affected the Napoleonic army during the Russian retreat.”
The study concludes that disease was a hidden partner in the disaster; “Microbes also tell their story” when science listens to it, revealing that what defeated the “Great Army” was not direct combat alone, but a network of debilitating factors, primarily intestinal infections and louse-borne fever.