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Swine Flu

This information is provided by the Center for Disease Control

What is novel H1N1 (swine flu)?



Why is novel H1N1 virus sometimes called swine flu?



How does novel H1N1 virus spread?

Spread of novel H1N1 virus is thought to occur in the same way that seasonal flu spreads. Flu viruses are spread mainly from person to person through coughing or sneezing by people with influenza. Sometimes people may become infected by touching something such as a surface or object with flu viruses on it and then touching their mouth or nose.


What are the signs and symptoms of this virus in people?

The symptoms of novel H1N1 flu virus in people include fever, cough, sore throat, runny or stuffy nose, body aches, headache, chills and fatigue. A significant number of people who have been infected with this virus also have reported diarrhea and vomiting. As with seasonal flu, severe illnesses and death have occurred as a result of illness associated with this virus.


How severe is illness associated with novel H1N1 flu virus?


In seasonal flu, certain people are at high risk of serious complications. This includes people 65 years and older, children younger than five years old, pregnant women, and people of any age with certain chronic medical conditions. About 70 percent of people who have been hospitalized with this novel H1N1 virus have had one or more medical conditions previously recognized as placing people at high risk of serious seasonal flu-related complications. This includes pregnancy, diabetes, heart disease, asthma and kidney disease.

One thing that appears to be different from seasonal influenza is that adults older than 64 years do not yet appear to be at increased risk of novel H1N1-related complications thus far. CDC laboratory studies have shown that no children and very few adults younger than 60 years old have existing antibody to novel H1N1 flu virus; however, about one-third of adults older than 60 may have antibodies against this virus. It is unknown how much, if any, protection may be afforded against novel H1N1 flu by any existing antibody.




When the novel H1N1 outbreak was first detected in mid-April 2009, CDC began working with states to collect, compile and analyze information regarding the novel H1N1 flu outbreak, including the numbers of confirmed and probable cases and the ages of these people.

The information analyzed by CDC supports the conclusion that novel H1N1 flu has caused greater disease burden in people younger than 25 years of age than older people. At this time, there are few cases and few deaths reported in people older than 64 years old, which is unusual when compared with seasonal flu. However, pregnancy and other previously recognized high risk medical conditions from seasonal influenza appear to be associated with increased risk of complications from this novel H1N1. These underlying conditions include asthma, diabetes, suppressed immune systems, heart disease, kidney disease, neurocognitive and neuromuscular disorders and pregnancy.


How long can an infected person spread this virus to others?



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Reviewed 9/5/2009
By Daniel Feiten MD
Greenwood Pediatrics