Study: Napoleon's Army Destroyed by Lice

Discovery Channel News
Lice played a key role in Napoleon Bonaparte's disastrous invasion of Russia in 1812, according to genetic research into the skeletal remains of the ill-fated army.

Napoleon marched into Russia in the summer of 1812, leading the largest army Europe had ever seen, some half million soldiers, toward Moscow.

The invasion was the French emperor's answer to tzar Alexander I's refusal of the Continental System, a system of economic preference and protection within Europe aimed to exclude British trade and reinforce the French economy at the expense of the other states.

Six months later, the Grande Armée was reduced to 25,000 men who retreated to Vilnius, Lithuania, in the freezing cold. Only 3,000 survived the war, weather and disease to continue the retreat. The dead were buried in mass graves.

One such grave, containing between 2,000 and 3,000 corpses, was discovered in 2001 in Vilnius during some construction work.

Analysis of the remains produced hard genetic evidence that louse-borne pathogens were a major factor in the French retreat from Russia, Didier Raoult, of the Université de la Méditerranée in Marseille, and colleagues reported in the January issue of The Journal of Infectious Diseases.

"We believe that louse-borne diseases caused much of the death of Napoleon's army," Raoult told Discovery News.

Human body lice transmit Borrelia recurrentis, Bartonella quintana and Rickettsia prowazekii, the agents of louse-borne relapsing fever, trench fever and epidemic typhus, respectively.

Raoult and colleagues analyzed two kilograms of earth from the mass grave containing bone fragments and remnants of clothing and identified body segments of five lice.

Three of them carried DNA from relapsing fever.

The scientists then analyzed dental pulp from 72 teeth, taken from the remains of 35 soldiers. The sequencing revealed DNA of Bartonella quintana in seven soldiers.

"We believe that these findings provide firm evidence that the soldiers had trench fever," wrote the researchers.

The team also detected the DNA of Rickettsia prowazekii in three other soldiers, indicating that Napoleon's army also suffered from epidemic typhus.

Overall, nearly one-third of Napoleon's soldiers buried in Vilnius were affected by louse-borne infectious diseases, the researchers concluded.

"This is very important and exciting research because it provides compelling physical evidence for the impact of louse-borne diseases on Grand Army troops during Napoleon's invasion of, and retreat from, Russia," Robert Peterson, an expert of insect ecology and agricultural and biological risk assessment at Montana State University, told Discovery News.