Influenza Pandemic, 1918-1919

**Definition:** The influenza outbreaks of 1918 to 1919 also known as Spanish flu pandemic. First reported in Haskell County in Kansas in March of 1918 the disease spread throughout the world and may have killed as many as 25 million people.

**Tree numbers:** - K01.400.504.968.450

**Synonyms:** - H1N1 Influenza Pandemic, 1918-1919 - Spanish Flu Pandemic, 1918-1919