H1N1 Flu - What It Is and Is Not
I heard that H1N1 flu is pandemic–what does that mean?
This means that influenza due to the H1N1 virus is occurring in multiple countries around the world and that human infection is widespread. However, this does not mean that the severity of the illness has increased. Despite its wide and quick spread, most people who have gotten H1N1 flu have had mild illness. Unfortunately, some people in New York State, in the United States, and in other countries have developed more severe illness and some have died. At this time, it is uncertain how many people with H1N1 flu will develop serious complications during this pandemic.
What is H1N1 flu?
H1N1 flu is an influenza virus that was seen for the first time in the United States in April 2009. Health officials initially called it "swine flu" because it looked similar to some flu viruses that pigs get. However, further study showed that H1N1 flu contains a combination of flu virus genes found in some pigs, humans, and birds. You may hear or see H1N1 flu called "2009 H1N1 flu," "H1N1 flu," or "pandemic (H1N1) 2009" - these all refer to the same H1N1 flu. Although H1N1 flu is often called "swine flu," it is not the same.
Is H1N1 flu the same as swine flu?
No. Swine flu is a respiratory disease that pigs get that is caused by a different influenza virus. Outbreaks of swine flu happen regularly in pigs. People do not normally get swine flu, although sometimes people who work or live around pigs can get it. Very rarely, people with swine flu can spread it to others.
Is H1N1 flu the same as seasonal flu?
No. Some differences between seasonal flu and H1N1 flu are:
| Seasonal Influenza | H1N1 Flu | |
|---|---|---|
| When flu occurs: | Every year; usually winter and early spring | First identified April 2009; continuing to present |
| Age group most affected: | People 65 years and older | Children and young adults (5-24 years old) |
| Vaccine available: | Yes, available every year; available now | Yes, available now |
Learn more about seasonal flu and the seasonal flu vaccine.
Is H1N1 flu the same as the avian flu (bird flu) that has been in the news in recent years?
No. Even though H1N1 flu contains avian (bird) genes, it is not the same. The bird flu virus that has been watched closely is categorized as influenza A (H5N1), and is transmitted primarily among birds. This strain of avian flu (bird flu) has not been found in the United States.
