Influenza

Influenza Virus magnified 100,000X

What is Influenza?

Virus; causes chills, fever, sore throat, fatigue

How many people die each year from Influenza?

250,000 – 500,00 worldwide; 40,000 in US

(7th leading cause of death)

USA

How many people died in 1918 from Influenza?

40 – 100 million people

(3% of world’s population; as many that died in all wars in 20th century combined)

How many people died in 1918 from Influenza?

Did more people die because more people were infected with

Influenza?Usually – 0.1% of people infected die

1918 – about 10% of all infected people died

Who was dying?Young adults

Have there been other influenza epidemics since 1918?

Asian Flu (1957) – 1.5 million people died

Hong Kong Flu (1968) – 1 million people died

Influenza which caused the Hong Kong Flu

What made the 1918 Influenza virus so powerful and why did scientists think that

this year’s virus would be so bad?

Hemagglutinin – helps with viral entry (16 types)

Neuraminidase – helps with viral release (9 types)Asian Flu (1957) – Type H2N2Hong Kong Flu (1968) – Type H3N2

1918 Flu - H1N1

How do new Influenza Viruses

form?

Influenza can infect birds, humans, and pigs

How do new Influenza Viruses form?

Antigenic Shift – Influenza can infect pigs, birds, humans; parts from different virus strains are mixed.

2006 – Avian FluH1N7H5N1

H1N1

Link to Nova SCIENCENOW Video