{"id":11427,"date":"2026-02-11T17:09:16","date_gmt":"2026-02-11T23:09:16","guid":{"rendered":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/?p=11427"},"modified":"2026-02-11T17:09:20","modified_gmt":"2026-02-11T23:09:20","slug":"encephalitis-lethargica-the-strange-disease-that-killed-500000-people-and-then-abruptly-disappeared","status":"publish","type":"post","link":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/2026\/02\/11\/encephalitis-lethargica-the-strange-disease-that-killed-500000-people-and-then-abruptly-disappeared\/","title":{"rendered":"Encephalitis Lethargica: The Strange Disease That Killed 500,000 People, And Then Abruptly Disappeared"},"content":{"rendered":"<div class=\"panel body-content\"><div class=\"panel__container\">\n<p><a href=\"https:\/\/www.iflscience.com\/encephalitis-lethargica-the-strange-disease-that-killed-500000-people-and-then-abruptly-disappeared-82511\">IFL Science<\/a> The disease affected millions, but to this day has not been satisfactorily explained. The symptoms were pretty distressing. Around a century ago, and around the same time the 1918 influenza pandemic killed between\u00a0<a href=\"https:\/\/www.redcross.org.uk\/stories\/health-and-social-care\/health\/coronavirus-how-the-red-cross-helped-in-the-spanish-flu-pandemic\" target=\"_blank\" aria-label=\"50 and 100 million people worldwide, opens in a new window\" rel=\"noreferrer noopener\">50 and 100 million people worldwide<\/a>, humanity was met with a new and unusual disease. The disease, known as encephalitis lethargica (EL), first<em>\u00a0<\/em>began to spread across Europe in the winter of\u00a0<a href=\"https:\/\/academic.oup.com\/brain\/article\/140\/8\/2246\/3970828\" target=\"_blank\" aria-label=\"1916, opens in a new window\" rel=\"noreferrer noopener\">1916<\/a>. Constantin von Economo, a doctor at the Psychiatric-Neurological Clinic of the University of Vienna, was the first to describe the disease after several patients showed up with strange neurological symptoms. They were admitted with diagnoses ranging from meningitis and\u00a0<a href=\"https:\/\/www.iflscience.com\/groundbreaking-discovery-of-two-ms-subtypes-could-lead-to-new-targeted-treatments-82093\" target=\"_blank\" aria-label=\"multiple sclerosis, opens in a new window\" rel=\"noreferrer noopener\">multiple sclerosis<\/a>\u00a0to delirium. But none of these symptoms fit neatly into any known disease, and one new symptom \u2013 lethargy, or sleepiness \u2013 distinguished it as a new phenomenon. It was categorized as either acute or chronic, though the two phases often blended together.\u00a0<\/p>\n\n\n\n<figure class=\"wp-block-embed is-type-video is-provider-youtube wp-block-embed-youtube wp-embed-aspect-16-9 wp-has-aspect-ratio\"><div class=\"wp-block-embed__wrapper\">\n<iframe loading=\"lazy\" title=\"This Disease Turned 5 Million People Into Statues, And Then Vanished\" width=\"500\" height=\"281\" src=\"https:\/\/www.youtube.com\/embed\/tib0lgpjbu8?feature=oembed\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture; web-share\" referrerpolicy=\"strict-origin-when-cross-origin\" allowfullscreen><\/iframe>\n<\/div><\/figure>\n\n\n\n<p>&#8220;Acute encephalitis lethargica often presented as a gradual onset of non-descript flu-like symptoms, including malaise, low-grade fever, pharyngitis, shivering, headache, vertigo, and vomiting,&#8221; a 2017 review of the topic&nbsp;<a href=\"https:\/\/academic.oup.com\/brain\/article\/140\/8\/2246\/3970828\" target=\"_blank\" aria-label=\"explains, opens in a new window\" rel=\"noreferrer noopener\">explains<\/a>. &#8220;Neurological symptoms followed and could present very quickly, as in the case of a girl who experienced a sudden hemiplegia while walking home from a concert. Within half an hour she was asleep, and died 12 days later.&#8221;<\/p>\n<\/div><\/div>","protected":false},"excerpt":{"rendered":"<p>IFL Science The disease affected millions, but to this day has not been satisfactorily explained. The symptoms were pretty distressing. Around a century ago, and around the same time the 1918 influenza pandemic killed between\u00a050 and 100 million people worldwide, humanity was met with a new and unusual disease. The disease, known as encephalitis lethargica [&hellip;]<\/p>\n","protected":false},"author":11,"featured_media":11428,"comment_status":"open","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2}},"categories":[18],"tags":[],"class_list":["post-11427","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-coping-with-covid"],"jetpack_publicize_connections":[],"jetpack_featured_media_url":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-content\/uploads\/2026\/02\/Screenshot-2026-02-11-at-18.06.04.png","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/posts\/11427","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/users\/11"}],"replies":[{"embeddable":true,"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/comments?post=11427"}],"version-history":[{"count":1,"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/posts\/11427\/revisions"}],"predecessor-version":[{"id":11429,"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/posts\/11427\/revisions\/11429"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/media\/11428"}],"wp:attachment":[{"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/media?parent=11427"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/categories?post=11427"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.unmc.edu\/healthsecurity\/transmission\/wp-json\/wp\/v2\/tags?post=11427"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}