Napoleon’s soldiers who died in Russian retreat had unexpected diseases, study finds | Napoleon Bonaparte

Disaster struck when Napoleon ordered his army to withdraw from Russia in October 1812. An estimated 300,000 soldiers died from hunger, cold, exhaustion and disease.

Researchers now say they have identified two unexpected illnesses – paratyphoid fever and relapsing fever – among soldiers who died during the retreat, providing new insight into their plight.

“I think the most important reason for this is [the retreat] cold, hunger, etc., it was such a failure. “With or without infectious diseases, they would have died en masse,” said Nicolás Rascovan, head of the microbial paleogenomics unit at the Pasteur Institute and author of the study. “But I think it is what it is. [does] change is part of our knowledge of all infectious diseases.”

Writing in Current Biology magazineRascovan and colleagues describe how previous DNA analysis from soldiers buried in the same mass grave in Vilnius, Lithuania, revealed evidence of typhus and trench fever.

But this study relied on a very sensitive technique called nested PCR, which involves screening samples for specific pathogens.

Using a different technique, called shotgun sequencing, Rascovan’s team was able to look for DNA fragments that matched any of 185 bacteria known to cause disease in humans.

The results, based on DNA taken from the teeth of 13 soldiers who had not been studied before, revealed that one soldier was infected with lice-borne bacteria. Borrelia relapsings and the other four were infected with a type of bacteria that caused relapsing fever. Salmonella entericaIt causes paratyphoid fever, a disease spread through contaminated food or water. The team said that one of these four soldiers may have had a recurrence of fever.

The findings match historical descriptions of symptoms experienced by Napoleon’s soldiers, researchers say. Grand Armysuch as fever and diarrhea.

But unlike previous studies, the team found no trace of the bacteria that cause typhus or trench fever. Rascovan noted that these soldiers did not contract these diseases or may have only had a mild infection; however, the results could alternatively be explained by the degradation of ancient DNA over time or by the amount of DNA present being below the detection limit of the technique used.

The researchers performed a series of statistical tests and analyzes to ensure that their results were robust and pointed to real infections. These included looking for signs of DNA degradation that would be expected from the original ancient DNA, and investigating where the DNA belonged in the evolutionary “family tree” of the two bacteria.

“In light of our results, a plausible scenario for the deaths of these soldiers could be a combination of fatigue, cold, and various diseases, including paratyphoid fever and lice-induced relapsing fever. Although not fatal, lice-induced relapsing fever can significantly debilitate an already exhausted individual,” they write.

European history expert from King’s College London, Dr. Michael Rowe welcomed the work.

“Science is interesting because I think it does something that a historian cannot do,” he said, referring to the identification of diseases.

But he cautioned against the assumption that the devastation in the army was due to harsh weather conditions that left soldiers prone to starvation and disease; A view supported by Napoleon.

“That underestimates the Russians, and it underestimates the fact that they are doing some really smart things. [have] “They have a very good strategy and they actually have a very advanced army,” he said.