The plague, the rare bacterial infection infamously known for killing tens of millions in 14th-century Europe, never went away . It is now easily treated with antibiotics. Since the 1990s, most human cases have been reported in Africa, especially Congo and Madagascar, according to the World Health Organization . There are an average of about seven human cases per year in the U.S., according to the Centers for Disease Control and Prevention , mostly in rural areas of the American West. A worker at a plague research institute in Siberia recently died of pneumonia. The case has raised alarm in Russia after unconfirmed media reports suggested she might have died of pneumonic plague. Russian authorities say testing showed no evidence of plague, but the research institute has been quarantined. “People think the plague is gone, it was something that occurred 500 years ago. It’s not. It’s here amongst us,” said Simon Clarke of the University of Reading in the U.K. “Unless you get rid of those wild animals, which of course is not possible, then you’re not going to get rid of the bacte

