Bird Flu Genetic Instability in Korea
Recombinomics Commentary
February 8, 2005
New Korean avian influenza sequences have become publicly available at GenBank. The 112 genes from 16 isolates from 2003 greatly expand the data base of recent Korean isolates. Included in the sequences are subtypes H9N2, H3N2, and H6N1 from chickens ducks and doves.
A/duck/Korea/S17/03(H6N1)
A/dove/Korea/S11/03(H3N2)
A/duck/Korea/S10/03(H3N2)
A/duck/Korea/S9/03(H3N2)
A/duck/Korea/S8/03(H3N2)
A/duck/Korea/S7/03(H3N2)
A/chicken/Korea/S6/03(H3N2)
A/chicken/Korea/S18/03(H9N2)
A/chicken/Korea/S16/03(H9N2)
A/chicken/Korea/S15/03(H9N2)
A/dove/Korea/S14/03(H9N2)
A/duck/Korea/S13/03(H9N2)
A/chicken/Korea/S12/03(H9N2)
A/chicken/Korea/S5/03(H9N2))
A/chicken/Korea/S4/03(H9N2)
A/silky chicken/Korea/S3/03(H9N2)
These sequences point to the extreme genetic diversity in Korea in 2003. Additional H9N2 and H1N1 isolates from chickens and pigs in 2004 has significantly added to this diversity since the swine sequences included genes from the human flu virus WSN/33. The swine isolates contain significant reassortment. 6 of the swine sequences contain human WSN/33 genes (7,5,4,3). In additional, there is recombination within the N2 (avian / avian) and PB2 (avian / human) genes and acquisition of swine sequences.
The 16 sequences from 2003 add to the genetic instability in Korea. The failure to acknowledge this volatile genetic mixture in Korea by the WHO is cause for additional concern since the WHO has known about this situation for at least 3 months, and the infections continue to spread, increasing the chances of a pandemic influenza to emerge. In addition, s H5N2 was recently detected, which could lead to H5N1 reassortants.
Monitoring of avian influenza remains scandalous.