H1N1 (Swine Influenza) Information

H1N1 is a type of influenza (flu) virus that causes respiratory disease that can spread between people. Most people infected with this virus in the United States have had mild disease, but some have had more severe illness, and there have been some deaths. Young children, pregnant women, and people with chronic diseases like asthma, diabetes, or heart disease may be at higher risk for complications from this infection.