Continuing evolution of H9 influenza viruses in Korean poultry.
We analyzed the evolution of H9 influenza viruses isolated from Korean chicken farms from 2002 to 2004. Korean H9 viruses formed two antigenically distinct groups: those isolated from 1996 to mid-2003, and those isolated from late 2003 through 2004. Most of the 2004 isolates showed greater cross-reactivity with the second group than with the first group. Phylogenetic analysis of the 12 viruses studied revealed three genotypes of H9N2 viruses and showed that reassortment had occurred. One isolate, Ck/Kor/164/04, belonged to the H9N8 subtype. Its HA and PB1 genes were similar to those of the H9N2 viruses, but its other genes were closely related to H3N8 viruses. This report is the first (to our knowledge) of H9N8 infection in this host. The pathogenicity of the early isolates altered due to antigenic drift and reassortment, leading to H9 avian influenza viruses in Korea that potentially can expand their host range to mammalians.
Lee
Youn-Jeong
YJ
Avian Disease division, National Veterinary Research and Quarantine Service, 480 Anyang, Anyang city, 430-824, Korea.
Shin
Jin-Young
JY
Song
Min-Suk
MS
Lee
Young-Min
YM
Choi
Jun-Gu
JG
Lee
Eun-Kyoung
EK
Jeong
Ok-Mi
OM
Sung
Haan-Woo
HW
Kim
Jae-Hong
JH
Kwon
Yong-Kuk
YK
Kwon
Jun-Hun
JH
Kim
Chul-Joong
CJ
Webby
Richard J
RJ
Webster
Robert G
RG
Choi
Young Ki
YK
D000818:Animals; D000956:Antigens, Viral / Q000235:genetics; D002645:Chickens / Q000821:virology*; D019143:Evolution, Molecular; D005838:Genotype; D019267:Hemagglutinin Glycoproteins, Influenza Virus / Q000235:genetics; D053123:Influenza A Virus, H3N8 Subtype / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D053127:Influenza A Virus, H9N2 Subtype / Q000235:genetics* / Q000302:isolation & purification / Q000472:pathogenicity; D005585:Influenza in Birds / Q000453:epidemiology / Q000821:virology*; D007723:Korea / Q000453:epidemiology; D051379:Mice; D013047:Specific Pathogen-Free Organisms; D014779:Virus Replication
D000956:Antigens, Viral; D019267:Hemagglutinin Glycoproteins, Influenza Virus