#3907
Anonymous
Guest

You are right about all of these viruses being linked genetically to a goose virus from Guangdong in 1996 but there have been a number of jumps in the evolution of some strains for which the immediate precursor is not known and so we can only specualte on where they came from.

The paper at the following website from Emerging Infectious Diseases provides more on the various ‘clades’

http://www.cdc.gov/ncidod/EID/vol11no10/05-0644.htm