The researchers are excavating the graveyard surrounding the abandoned Badia Pozzeveri church in the Tuscany region of Italy.

The site contains victims of the cholera epidemic that swept the world in the 1850s, said Clark Spencer Larsen, professor of anthropology at Ohio State University and one of the leaders of the excavation team.

Archaeologists and their students have spent the past four summers painstakingly excavating remains in a special section of the cemetery used for cholera victims. About 20 to 30 skeletons have been excavated during each of the past four field seasons.

Finding traces of the pathogen that caused cholera among the human remains could reveal details about how people lived – and died – in this region of Europe. “To our knowledge, these are the best preserved remains of cholera victims of this time period ever found,” Larsen said. “We’re very excited about what we may be able to learn.”

Larsen discussed the project earlier this week at the annual meeting of the American Association for the Advancement of Science in San Jose.

The bodies of the cholera victims were hastily buried and covered in lime, which hardened like concrete around the bodies. Researchers suspect residents were trying to keep the disease from spreading. “But the lime encasing is pretty amazing for bone preservation, too,” Larsen said.

Not just the bones were preserved. The lime trapped soil around the bodies that contains the ancient DNA of bacteria and other organisms that lived in the humans buried there. One of Larsen’s colleagues, Hendrik Poinar, a professor at McMaster University in Hamilton, Canada, is an expert in ancient DNA and is scanning the soil samples for DNA from Virbrio cholera, the bacterium that causes cholera.