health fairs. Flu Facts
What is influenza?
Influenza is commonly called the flu. It is an acute respiratory disease caused by the influenza viruses A, B, and C. The virus is spread from infected persons to the nose and throat of others. In the United States, the flu is most common between November and April.
How is it spread?
The flu usually spreads from person to person when an infected
person coughs, sneezes, or talks and the virus is sent into the
air. Unlike many other viral respiratory infections, such as the
common cold, the flu causes severe illness and life-threatening
complications in many people.
How many people get sick or die from the flu every year?
Each flu season is unique, but it is estimated that approximately
10% to 20% of U.S. residents get the flu, and an average of 114,000
persons are hospitalized for flu-related complications. About
20,000 Americans die on average per year from the complications
of flu.
Who can get the flu?
Anyone can get the flu, therefore getting the influenza vaccine
will reduce the risk of getting the infection, developing complications
or transmitting the virus to others. See "Who
should get a flu shot?" for more information on who is
at highest risk for getting influenza.
What is a pandemic?
A pandemic is a worldwide epidemic of a disease. When a new subtype of flu virus appears after antigenic shift and the new virus can cause illness in people and can be spread easily from person to person, an influenza pandemic can occur. During the last 100 years there have been three flu pandemics:
1918-19, “Spanish flu,” [influenza A(H1N1)], caused the highest number of known flu deaths: more than 500,000 people died in the United States, and 20-50 million people may have died worldwide. The flu virus that caused it was very deadly. Many died within the first few days after infection and others died of complications soon thereafter. The Spanish flu was unique because almost half of the people who died were young, healthy adults.
1957-58, “Asian flu,” [influenza A(H2N2)], caused
approximately 70,000 deaths in the United States. The Asian flu
was first identified in late February, 1957 in China and spread
to the United States by June, 1957.
1968-69, “Hong Kong flu,” [influenza A(H3N2)], caused approximately 34,000 deaths in the United States. This pandemic H3N2 virus was first detected in Hong Kong in early 1968 and spread to the United States later that year. A(H3N2) viruses still circulate today.