Review and Discussion Time line courtesy of: Background image courtesy of: The History of Influenza

1918 ~ The Spanish Influenza Pandemic H1N1 The most devastating flu pandemic in recent history Killing more than 500,000 people in the United States 20 million to 50 million people worldwide An emergency hospital for influenza patients Image courtesy of:

Discussion Points from “The Enigma of the 1918 Influenza Pandemic ” Why was the Spanish Flu Pandemic so catastrophic? –Describe some of the hypotheses in the article Why was it difficult to identify the cause of the Spanish Flu? Describe the first wave of the Spanish Flu Describe the second wave of the Spanish Flu Describe the third wave of the Spanish Flu Describe some of the measures that were taken in San Francisco to combat the flu. Image courtesy of:

~ The Asian Flu Pandemic H2N2 First identified in China  spread to the rest of Asia, the Middle East and Europe, and the Americas Due to advances in scientific technology, the virus was quickly identified and a vaccine was available by August of 1957 The Asian Flu hit young people and children especially hard, the elderly suffered the highest death rates from the disease Influenza peaked in the United States between September and December, with a second wave emerging in January and February Caused roughly 70,000 deaths in the United States during the season

~ Hong Kong Flu Pandemic H3N2 First detected in Hong Kong –significant impact on Hong Kong, infecting 15% of the population –Quickly spread throughout the world following a pattern similar to that of the Asian Flu pandemic Caused roughly 34,000 deaths in the United States during the season –Much lower than that of the Asian Flu – may be because the Hong Kong strain had only a surface antigenic shift from pre-existing A-strains which resulted in partial pre-existing immunity in individuals H3N2 viruses still circulate today

Major Flu Pandemics: Number of Deaths in the USA Image courtesy of: