What is swine flu?
HIN1 Influenza is a respiratory disease of pigs caused by type A influenza viruses that causes regular outbreaks in pigs. People do not normally get swine flu, but human infections can and do happen. Swine flu viruses have been reported to spread from person-to-person, but in the past, this transmission was limited and not sustained beyond three people.

Are there human infections with H1N1 flu in the U.S.?
In late March and early April 2009, cases of human infection with H1N1 influenza A viruses were first reported in Southern California and near Guadalupe County, Texas. Other U.S. states have reported cases of H1N1 flu infection in humans and cases have been reported internationally as well. Updated case counts of confirmed H1N1 flu infections in the United States is available on the CDC website. CDC and local and state health agencies are working together to investigate this situation.

Is this H1N1 flu virus contagious?
CDC has determined that this H1N1 influenza A virus is contagious and is spreading from human to human. However, at this time, it is not known how easily the virus spreads between people.

What are the signs and symptoms of H1N1 flu in people?
The symptoms of H1N1 flu in people are similar to the symptoms of regular human flu and include fever, cough, sore throat, body aches, headache, chills and fatigue. Some people have reported diarrhea and vomiting associated with H1N1 flu. In the past, severe illness (pneumonia and respiratory failure) and deaths have been reported with H1N1 flu infection in people. Like seasonal flu, H1N1 flu may cause a worsening of underlying chronic medical conditions.

How does H1N1 flu spread?
Spread of this H1N1 influenza A virus is thought to be happening in the same way that seasonal flu spreads. Flu viruses are spread mainly from person to person through coughing or sneezing of people with influenza. Sometimes people may become infected by touching something with flu viruses on it and then touching their mouth or nose.

How can someone with the flu infect someone else?
Infected people may be able to infect others beginning 1 day before symptoms develop and up to 7 or more days after becoming sick. That means that you may be able to pass on the flu to someone else before you know you are sick, as well as while you are sick.