DNA Uncovers the Illness that Plagued Napoleon’s Defeated Army

As Napoleon advanced into Russia in 1812, he commanded the largest army ever assembled in Europe. However, his return was marked not by gunfire, but by the chilling impact of microscopic foes.

Scientists examining DNA from the teeth of soldiers who perished during the retreat from Moscow have uncovered two diseases that devastated the Tsar’s grand army.

Historically, “typhus has been regarded as the most widespread illness in the military,” stated Nicolas Raskovan, director of the microbial paleogenomics department at the Pasteur Institute and lead author of the research. The findings were published in “Current Biology”.

Employing a method known as shotgun sequencing, Raskovan and his team investigated ancient DNA from the dental remains of 13 soldiers discovered near Vilnius, Lithuania, and identified two “previously undocumented pathogens.”

“We have confirmed the presence of Salmonella enterica, which is part of the Paratyphoid C strain,” he explained to NBC News, noting this bacteria is responsible for paratyphoid fever, along with Borrelia ricerentis, the agent of relapsing fever.

These diseases would likely have thrived in environments where “sanitation and hygiene were severely lacking,” he added.

The results align with historical accounts detailing symptoms like fever and diarrhea that plagued Napoleon’s troops, according to the study.

A “reasonable scenario” for the fatalities might include “extreme fatigue, cold weather, and multiple illnesses, such as paratyphoid fever or louse-borne relapsing fever,” the researchers noted.

“Although not necessarily deadly, louse-borne relapsing fever can be profoundly debilitating for someone already worn down,” they added.

In contrast to a 2006 study that discovered traces of bacteria causing typhus and trench fever in four out of 35 individuals, this research found no evidence of those illnesses.

However, Raskovan noted that while early research was constrained by the technology at the time, both old and new findings paint a clearer picture of the factors that led to the downfall of Napoleon’s forces.

“The discovery of four different pathogens in such a significant number of individuals strongly indicates that a variety of infections were widespread,” he remarked.

Approximately 300,000 lives were lost before Napoleon’s army retreated. It appears even an emperor cannot conquer the realm of microorganisms.

Source: www.nbcnews.com

New DNA Evidence Uncovers the True Reasons Behind Napoleon’s Army Defeat

Researchers have uncovered new DNA evidence that challenges established theories regarding Napoleon’s ill-fated 1812 invasion of Russia. As his Grand Army, comprising around 500,000 soldiers, advanced toward Moscow, it encountered severe resistance, dwindling resources, and the harshness of winter.

As the troops began their retreat, starvation and disease were rampant. Analyzing the remains of soldiers now indicates that multiple infectious diseases may have caused the significant loss of life in the French emperor’s army, rather than typhus being the singular primary cause of devastation.

A recent study led by Dr. Nicholas Raskovan at the Pasteur Institute in Paris involved extracting genetic material from the teeth of 13 soldiers interred in a mass grave in Vilnius, Lithuania.

Through ancient DNA sequencing, no evidence of typhus was identified. Instead of the long-suspected bacteria rickettsia, the team pinpointed two distinct pathogens: salmonella enterica, which causes enteric fever (like typhoid), and Borrelia recurrentis, linked to recurring fever.

Raskovan mentioned, “Our research alters the understanding of pathogens previously unrecognized,” as reported in BBC Science Focus.

Previous research employed PCR tests, akin to those used in contemporary COVID-19 testing, to search solely for specific microorganisms. Currently available technology enables scientists to “cast a wider net,” allowing them to detect DNA fragments from all microorganisms present, Raskovan explained.

“Thanks to advancements in technology, we now have insights that were unimaginable a decade ago,” Raskovan noted.

“When we integrate our prior and current research, we discover that four different diseases affected just a small group of individuals. This implies that a single pathogen didn’t account for all the 3,000 deaths, but rather, these individuals were infected with various pathogens.”

The DNA extracted from these teeth was analyzed using cutting-edge technology to identify pathogens, even in trace amounts. Credit: © European Commission / Claudio Centonze

In essence, the situation for Napoleon’s army during their retreat from Russia was dire, facilitating the spread of various diseases. It was almost inevitable that if one illness was avoided, another would take hold.

The research also highlighted the strain Borrelia recurrentis found at the site, which is genetically identical to those from Iron Age Britain, approximately 2,000 years ago, a lineage that has since vanished.

Raskovan stated, “This strain derives from an ancestor that either no longer exists or is currently unknown. This emphasizes the significant changes in sanitation over the past two centuries, particularly with the advent of antibiotics that have virtually eradicated this once prevalent disease.”

For Raskovan, these ancient microorganisms are more than peculiar findings; they are historical witnesses. “For those infected, it’s not surprising,” he remarked. “For me, it’s fulfilling to reconstruct history.”

“These pathogens provide us with a means to learn about past populations and their dynamics.”

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Source: www.sciencefocus.com

DNA Analysis Uncovers the True Cause Behind the Demise of Napoleon’s Army in 1812

Napoleon’s retreat from Russia in 1812 Ary Scheffer

Iandagnall Computing / Alamy Stock Photo

During the retreat of Napoleon’s formidable 500,000-strong army from Russia in 1812, nearly half of the troops fell victim to disease, starvation, and freezing temperatures. Recent advanced DNA analysis is shedding light on the pathogens involved in this tragic demise.

In the summer of 1812, Napoleon amassed an army of 600,000 to invade Russia but was compelled to withdraw from Moscow, depleting the city of resources, and retreat toward the Polish border for the winter. From October to December 1812, around 300,000 French soldiers perished from famine, exposure, and illness.

Survivor accounts from that era indicate that typhoid fever and trench fever were leading causes of mortality and suffering among the troops, a premise that was further validated by genetic testing conducted nearly two decades ago.

Recently, Nicholas Rascovan and his team at the Pasteur Institute in Paris analyzed DNA extracted from the teeth of 13 soldiers interred in Vilnius, Lithuania.

The research team identified the presence of Salmonella enterica, which triggers peritoneal fever, and Borrelia recurrentis, a louse-borne pathogen that leads to recurrent fever.

Unlike earlier studies that relied on methods to amplify specific DNA sequences, Rascovan and his colleagues utilized advanced metagenomic techniques to detect genetic material from pathogens in the samples, allowing for a more extensive analysis.

“Considering our findings, it is plausible that the deaths of these soldiers were due to a combination of various illnesses, including fatigue, colds, lactophoreal fever, and louse-borne recurrent fever,” Rascovan and his team noted in an unpublished report. The team opted not to comment further on the story.

While not always lethal, louse-borne recurrent fever can considerably debilitate individuals who are already in a weakened state, according to the researchers.

Sally Wasef from the Queensland Institute of Technology in Australia opines that historical accounts of symptoms may correspond to multiple infectious diseases beyond those identified in the recent study.

Traces of microbial DNA were isolated from ancient remains, according to Wasef. “In my opinion, this implies that the conclusions drawn are more suggestive than definitive.”

Rascovan and his colleagues also acknowledge the necessity of examining a greater number of soldiers who perished during 1812.

The research underscores the potential of novel methodologies to identify possible infectious agents in historical populations, Wasef explains. She advocates for applying these techniques to study diseases in populations post-contact in regions like the US or Australia.

“Such research holds great promise for uncovering the impact of disease on historical population declines, particularly when written records are sparse or biased,” states Wasef.

topic:

  • Archaeology/
  • Infectious diseases

Source: www.newscientist.com