Distribution of amantadine-resistant H5N1 avian influenza variants in Asia

J Infect Dis. 2006 Jun 15;193(12):1626-9. doi: 10.1086/504723. Epub 2006 May 9.


We examined the distribution of genetic mutations associated with resistance to the M2 ion channel-blocking adamantane derivatives, amantadine and rimantadine, among H5N1 viruses isolated in Vietnam, Thailand, Cambodia, Indonesia, Hong Kong, and China. More than 95% of the viruses isolated in Vietnam and Thailand contained resistance mutations, but resistant mutants were less commonly isolated in Indonesia (6.3% of isolates) and China (8.9% of isolates), where human infection was recently reported. The dual mutation motif Leu26Ile-Ser31Asn (leucine-->isoleucine at aa 26 and serine-->asparagine at aa 31) was found almost exclusively in all resistant isolates from Vietnam, Thailand, and Cambodia, suggesting the biological selection of these mutations.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amantadine / pharmacology*
  • Amino Acid Substitution
  • Animals
  • Antiviral Agents / pharmacology
  • Asia
  • Birds
  • Drug Resistance, Viral / genetics*
  • Humans
  • Influenza A Virus, H5N1 Subtype / drug effects*
  • Influenza A Virus, H5N1 Subtype / genetics*
  • Influenza A Virus, H5N1 Subtype / isolation & purification
  • Influenza in Birds / virology
  • Influenza, Human / virology
  • Microbial Sensitivity Tests
  • Mutation, Missense
  • Rimantadine / pharmacology*


  • Antiviral Agents
  • Rimantadine
  • Amantadine