In October 2018, Davide Tanasi was off the coast of Italy, pulling teeth. His dental patients were 34 Sicilians who had been dead for the better part of 2,000 years. These Roman Christians were buried in the catacombs of St. Lucia in Syracuse, an underground city of some 8,000 dead stretched across an area about the size of the White House. Concealed among their no-longer-so-pearly whites was Bartonella quintana, a bacteria that causes a disease called trench fever, and which arrived in Roman mouths via the guts of lice. The…
