 A foodborne illness was suspected, and among these it was originally believed to be a case of "cursed bread" ("pain maudit").Most academic sources accept ergot poisoning as the cause of the epidemic, while a few theorize other causes such as poisoning by mercury, mycotoxins, or nitrogen trichloride.Fringe theorists have speculated that the United States Central Intelligence Agency (CIA) intentionally poisoned the population in order to test a "deliriant incapacitating agent" during the Cold War.