Avian influenza (bird flu) is a contagious disease of animals caused by influenza A viruses. These flu viruses occur naturally among birds. Actually, humans are not infected by bird flu viruses.. However, during an outbreak of bird flu among poultry, there is a possible risk to people who have contact infect birds or surface that have been contaminated with excreations from infected birds. Symptoms of bird flu in humans have ranged from typical flu-like symptoms to eye infections, pneumonia, severe respiratory diseases and other severe and life-threatening complications. In such situation, people should avoid contact with infected birds or contaminated surface, and should be careful when handling and cooking poultry.