H5N1 (Avian/Bird) flu is caused by influenza viruses that occur naturally among wild birds. Low pathogenic AI is common in birds and causes few problems. Highly pathogenic H5N1 is deadly to domestic fowl, can be transmitted from birds to humans, and is deadly to humans. There is virtually no human immunity and human vaccine availability is very limited.

Online Resources

• World Health Organization Avian Flu FAQs
• What is Avian Flu? - University of Virginia
• http://www.cdc.gov/flu/avian/