The expression “dance the night away” gained a more literal interpretation in 1518 when a “dancing plague” afflicted up to 400 people in Strasbourg, a modern-day French city. One woman, Frau Troffea, started the outbreak in July when she started boogying in the middle of the street on her own. She spent a whole week dancing by herself before the impulse to dance overcame the actions of several dozen other people. The number had increased to several hundred by the end of the month. After a while the enigmatic dance subsided and Strasbourg went back to its usual routine in September.
The unexplained increase in dance fever alarmed the authorities, but ignorant doctors dismissed it as “hot blood” and advised individuals to keep dancing until they lost the desire. As the weeks passed, a number of the dancers passed away from heart attacks and slumped from exhaustion. The people in the area looked for explanations, and some thought that St. Vitus, the patron saint of dance, had cursed them. Many contemporary historians speculate that this mass hysteria was probably caused by stress in addition to the emergence of new, untreated diseases like syphilis. Over the 500 years prior, there had been multiple documented outbreaks of “dancing plagues” throughout the Holy Roman Empire, with 1374 being one of the most notable. Another theory links ergot, a fungus that can occasionally be detected in bread, to bread. If ingested, the fungus induces convulsions, which could account for the uncontrollably dancing and other episodes of widespread panic.