Category: Mysterious Diseases and Epidemics

Encephalitis Lethargica 1916-1928: The Sleeping-Sickness Pandemic That Vanished Without Cause

Encephalitis lethargica, the so-called sleeping sickness, swept across at least 64 countries between 1916 and 1928, infected an estimated one million people, killed roughly half of them, and then — without an identified pathogen, without an isolated antibody, without a vaccine — receded into clinical rarity by 1930 and never returned at epidemic scale [1][2]. […]