Send to

Choose Destination
See comment in PubMed Commons below
Antiviral Res. 2009 Nov;84(2):199-202. doi: 10.1016/j.antiviral.2009.08.006. Epub 2009 Aug 29.

Amantadine-resistant influenza A viruses isolated in South Korea from 2003 to 2009.

Author information

  • 1Division of Influenza and Respiratory Viruses, Center for Infectious Diseases, National Institute of Health, Korea Centers for Disease Control & Prevention, Seoul, Republic of Korea.


To investigate the frequency of amantadine resistance among influenza A viruses isolated in Korea during the 2003-2009 seasons, 369 (16.8%) 2199 A/H1N1 viruses and 780 (14.8%) of 5263 A/H3N2 viruses were randomly selected. The M2 and HA1 genes of each isolate were amplified by reverse transcription-polymerase chain reaction and followed by nucleotide sequencing. The results showed that the resistance rate to amantadine among A/H1N1 viruses increased significantly from 2004-2005 (33.3%) to 2007-2008 (97.8%) and then decreased dramatically in 2008-2009 (1.9%). The A/H1N1 isolates recently detected in 2008-2009 turned amantadine-sensitive containing two new substitutions at specific sites (S141N, G185A) in HA1. Compared with A/H1N1 viruses, the amantadine resistance among the A/H3N2 viruses increased from 2003-2004 (9.7%) to 2005-2006 (96.7%) and decreased in 2006-2007 (57.4%). During 2006-2007, both of amantadine-resistant and -sensitive A/H3N2 viruses co-circulated but clustered in different branches phylogenetically. All of A/H3N2 isolates tested during 2007-2009 appeared to cluster in the same group being resistant to amantadine.

[PubMed - indexed for MEDLINE]

Publication Types, MeSH Terms, Substances, Secondary Source ID

Publication Types

MeSH Terms


Secondary Source ID

PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science
    Loading ...
    Write to the Help Desk