The 1918-1919 Influenza Pandemic

During World War I, an influenza virus erupted worldwide, killing between 50-100 million, including 675,000 Americans, between March 1918 and January 1919. Medical scientists and historians are unsure of the virus’ origin, but most assume that the strain emerged in the US in Haskell County, KS, when a US Army cook at Camp Funston became the first American death in March. This pandemic is commonly known in the West as the “Spanish” flu, but this name is a misnomer. Belligerent nations engaging in the Great War censored their newspapers, so initial reports of influenza only appeared in the press in neutral nations, like Spain. Since many of the early reports came from Spain, many believed the pandemic originated in Spain.

The 1918 flu pandemic was unique and terrifying. Average influenza epidemics kill the very young and the very old, making the shape of a “U” on mortality charts. This flu, however, killed millions of people between the ages twenty and forty, making a “W” on mortality charts. While epidemiologists (scientists who use microbiology, sociology, and statistics to study diseases) are still baffled by this phenomenon, they speculate that the virus killed healthy people through “cytokine storms.” To fight an influenza virus, the human body produces cells called “cytokines” as part of an immune attack against pathogens. In healthy adults, cytokine response is robust. The 1918 flu strain overloaded the immune system, so that the body could not stop producing cytokines, causing patients to drown in their own fluids.

Three waves of pandemic flu occurred internationally in just one year. The first was mild, beginning in March and ending around June. The second eclipsed many historic pandemics, killing millions between August and November 1918. Mobilization associated with large military movements like the Spring Offensive facilitated the spread of the flu in the first wave, in March. Demobilization, or the return of troops from Europe to the US and the vast European empires, closer to the war’s final months, also facilitated the global spread of the flu’s second lethal wave. A mild, final wave occurred between January and March 1919. In the US, local governments shut down public places and gatherings. Just as quickly as the pandemic surfaced, it disappeared taking millions of people, worldwide, with it.

For More Information:

“1918 Pandemic (H1N1 virus).” Centers for Disease Control and Prevention. Accessed June 26, 2019, https://www.cdc.gov/flu/pandemic-resources/1918-pandemic-h1n1.html.

“The American Influenza Epidemic of 1918-1919: A Digital Encyclopedia.” University of Michigan Center for the History of Medicine and Michigan Publishing, University of Michigan Library. Accessed June 26, 2019, https://www.influenzaarchive.org/.

Barry, John. The Great Influenza: The Epic Story of the Deadliest Plague in History. New York: Penguin Books, 2004.