[1] Shantou Univ, Coll Med, Joint Influenza Res Ctr, Shantou, Peoples R China
[2] Univ Hong Kong, Hong Kong, Hong Kong, Peoples R China
[3] St Jude Childrens Hosp, Dept Infect Dis, Memphis, TN 38105 USA
[4] Vet Publ Hlth Inst, Int Reference Lab Avian Influenza & Newcastle Dis, Legnaro, Italy
[5] Linnaeus Univ, Sch Nat Sci, Kalmar, Sweden