How does 2009 H1N1 flu compare to seasonal flu in its severity and infection rates?
The severity of seasonal flu varies from year to year, can cause mild to severe illness, and can sometimes lead to death. Each year, an average of 36,000 people in the United States die from flu-related complications, and more than 200,000 people are hospitalized from flu-related causes. The majority of deaths (about 90%) and about 60% of hospitalizations occur in people older than 65. Many children under age 5 are also hospitalized because of influenza. However, data gathered by the CDC indicates that H1N1 appears to cause more disease in people younger than 25 years of age than in older people. At this time, there are few cases and few deaths reported in people older than 64, which is unusual compared with seasonal flu. However, pregnancy and other previously recognized high-risk medical conditions from seasonal influenza may be associated with an increased chance of having severe illness resulting from H1N1 infection.