>>10 I think the scare you are refering to was SARS not H5N1. SARS was knew and had not been observed before. (See
http://www.answers.com/sars for background on SARS).
H5N1 is yet another flu. There is a long history of flu jumping from animals to humans and wiping out a good percentage of the human population. The 1918 Spanish flu is a good example, it resulted in over 20 million deaths world wide. The Spanish flu was also a bird flu.