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About avian influenza (flu)
- Differences between avian flu, seasonal flu and pandemic flu
Pandemic influenza is caused by a virus that is new to the human species, so the population does not have immunity to it. Seasonal flu is caused by one of many subtypes of influenza A and B viruses that circulate each year.
- Understanding avian influenza
Avian (bird) flu mainly affects birds, and only rarely infects humans. There are two bird flu viruses with limited circulation in humans. One has recently emerged in 2013 (H7N9). The other first emerged in humans in 2003 (H5N1).
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- Pandemic flu
A pandemic flu is a new influenza virus that could be a much more serious flu virus than seen in a typical flu season. Different from the typical strains of flu, humans would have no or little natural resistance to a new strain of influenza.
- Seasonal flu
Influenza is a contagious respiratory disease caused by a virus which infects many parts of the body, including the lungs. Someone who has the flu spreads the virus by sneezing, coughing, or even talking. Flu may be transmitted by direct hand contact.