For centuries, historians and scientists have puzzled over the calamitous plague of Athens, which decimated the ancient city-state between 430 and 427 B.C. As vividly described by the historian Thucydides, himself a survivor of the illness, the plague attacked suddenly, causing "violent heats" in the head, inflammation of the eyes and throat, "reddish, livid" skin, extreme diarrhea and high fever. Historians agree that the epidemic, which killed the great statesman Pericles, contributed to the fall of Athens in the Peloponnesian War. But there is no agreement on its cause. Was it smallpox? Scarlet fever? Typhus? Measles?
A more exotic explanation was...