The emergence of adamantane resistance in influenza A(H1) viruses in Australia and regionally in 2006.
The adamantanes (amantadine and rimantadine) were the first antivirals licensed for use against influenza A viruses and have been used in some countries to control seasonal influenza. While increasing resistance of A(H3) viruses to this class of drug has been reported in recent years, only low levels of resistance were seen with A(H1) viruses until the 2005-2006 influenza season in the USA. In this study we analysed 101 human influenza A viruses isolated in 2006 that were referred to the WHO Collaborating Centre for Reference and Research in Melbourne, from Australia and the surrounding regions, for evidence of resistance to adamantanes. We found that whereas previously A(H1) resistant viruses were rare, 21.8% of the 2006 viruses had a resistant genotype. By comparison, 58.6% of influenza A(H3) viruses isolated in 2006 that were tested at the Centre, had a resistant genotype.
Barr
I G
IG
WHO Collaborating Centre for Reference and Research on Influenza, 45 Poplar Road, Parkville, Melbourne 3052, Australia. Ian.Barr@influenzacentre.org
Hurt
A C
AC
Deed
N
N
Iannello
P
P
Tomasov
C
C
Komadina
N
N
D000218:Adamantane / Q000494:pharmacology / Q000627:therapeutic use*; D000293:Adolescent; D000328:Adult; D000368:Aged; D019943:Amino Acid Substitution; D000998:Antiviral Agents / Q000494:pharmacology / Q000627:therapeutic use; D001210:Asia, Southeastern / Q000453:epidemiology; D001315:Australia / Q000453:epidemiology; D002648:Child; D002675:Child, Preschool; D024882:Drug Resistance, Viral / Q000235:genetics; D005202:Asia, Eastern / Q000453:epidemiology; D005838:Genotype; D006801:Humans; D007223:Infant; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D053122:Influenza A Virus, H3N2 Subtype / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D007251:Influenza, Human / Q000188:drug therapy* / Q000453:epidemiology / Q000821:virology; D008875:Middle Aged; D010139:Pacific Islands / Q000453:epidemiology; D015995:Prevalence; D012299:Rimantadine / Q000494:pharmacology / Q000627:therapeutic use*; D013019:South Africa / Q000453:epidemiology
D000998:Antiviral Agents; D012299:Rimantadine; D000218:Adamantane