DNA from grave reveals pathogens that plagued Napoleon’s army

The retreat from Russia by Napoleon Bonaparte and the French Grande Armée in 1812 was a cataclysmic event that marked the beginning of the end for his empire and personal dominance in Europe, with about 300,000 soldiers perishing in a force that originally numbered roughly a half million.

A new study involving DNA extracted from the teeth of 13 French soldiers who were buried in a mass grave in Lithuania's capital Vilnius along the route of the retreat is offering a deeper understanding of the misery the Grande Armée experienced, detecting two pathogens not previously documented in this event.

"Vilnius was a key waypoint on the 1812 retreat route. Many soldiers arrived exhausted, starving and ill. A substantial number died there and were interred rapidly in mass graves," said molecular biologist and geneticist Nicolás Rascovan, head of the microbial paleogenomics unit at the Institut Pasteur in Paris and senior author of the study published in the journal Current Biology.

"While cold, starvation and typhus have long been emphasized, our results show that paratyphoid fever and louse-borne relapsing fever were also present and may have contributed to debilitation and mortality," Rascovan added.

Paratyphoid fever typically is food- or water-borne, with symptoms including fever, headache, abdominal pain, diarrhea or constipation, weakness and sometimes a rash.

The form of relapsing fever detected is transmitted by body lice and causes episodes of recurring high fever, with headache, muscle pain and weakness.