Epidemiology of human influenza A and B viruses in Myanmar from 2005 to 2007

Intervirology. 2009;52(6):310-20. doi: 10.1159/000237738. Epub 2009 Sep 17.

Abstract

Objectives: To perform genetic analysis of influenza A and B viruses in Myanmar from 2005 to 2007 and to determine the prevalence of amantadine-resistant influenza A viruses.

Methods: Phylogenies of the HA and NA genes were analyzed and mutations in M2 that confer resistance to amantadine were screened.

Results: Influenza in Myanmar exhibited seasonality, which coincided during the rainy season from June to August. Out of 2,618 samples, 76 influenza A and 132 influenza B viruses were isolated. Phylogenetic analysis showed that in 2005, 11 A/H1N1 isolates formed one cluster with A/Solomon Islands/3/2006 and were amantadine-sensitive strains. One A/H3N2 isolate was amantadine-resistant harboring S31N mutation in M2 and possessing S193F and D225N substitutions in HA (clade N), similar to A/Wisconsin/67/2005. No viruses were isolated in 2006 due to sample storage failure. In 2007, all 64 A/H3N2 isolates were amantadine-resistant and similar to A/Brisbane/10/2007. For influenza B, 3 Yamagata-lineage and 17 Victoria-lineage isolates were detected in 2005 and 112 Victoria-lineage viruses were isolated in 2007. All Victoria-lineage isolates were reassortants possessing NA derived from the Yamagata lineage.

Conclusion: Continuous surveillance in tropical countries is important for elucidating the seasonality of influenza and determining the molecular characteristics of circulating strains.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amantadine / pharmacology
  • Antiviral Agents / pharmacology
  • Drug Resistance, Viral / genetics
  • Hemagglutinin Glycoproteins, Influenza Virus / genetics
  • Humans
  • Influenza A Virus, H1N1 Subtype / drug effects
  • Influenza A Virus, H1N1 Subtype / genetics*
  • Influenza A Virus, H3N2 Subtype / drug effects
  • Influenza A Virus, H3N2 Subtype / genetics*
  • Influenza B virus / drug effects
  • Influenza B virus / genetics*
  • Influenza, Human / drug therapy
  • Influenza, Human / epidemiology*
  • Influenza, Human / virology
  • Molecular Sequence Data
  • Myanmar / epidemiology
  • Neuraminidase / genetics
  • Phylogeny
  • RNA, Viral / analysis
  • RNA, Viral / genetics
  • Seasons
  • Sequence Analysis, RNA

Substances

  • Antiviral Agents
  • Hemagglutinin Glycoproteins, Influenza Virus
  • RNA, Viral
  • Amantadine
  • Neuraminidase

Associated data

  • GENBANK/FJ229839
  • GENBANK/FJ229840
  • GENBANK/FJ229841
  • GENBANK/FJ229842
  • GENBANK/FJ229843
  • GENBANK/FJ229844
  • GENBANK/FJ229845
  • GENBANK/FJ229846
  • GENBANK/FJ229847
  • GENBANK/FJ229848
  • GENBANK/FJ229849
  • GENBANK/FJ229850
  • GENBANK/FJ229851
  • GENBANK/FJ229852
  • GENBANK/FJ229853
  • GENBANK/FJ229854
  • GENBANK/FJ229855
  • GENBANK/FJ229856
  • GENBANK/FJ229857
  • GENBANK/FJ229858
  • GENBANK/FJ229859
  • GENBANK/FJ229860
  • GENBANK/FJ229861
  • GENBANK/FJ229862
  • GENBANK/FJ229863
  • GENBANK/FJ229864
  • GENBANK/FJ229865
  • GENBANK/FJ229866
  • GENBANK/FJ229867
  • GENBANK/FJ229868
  • GENBANK/FJ229869
  • GENBANK/FJ229870
  • GENBANK/FJ229871
  • GENBANK/FJ229872
  • GENBANK/FJ229873
  • GENBANK/FJ229874
  • GENBANK/FJ229875
  • GENBANK/FJ229876
  • GENBANK/FJ229877
  • GENBANK/FJ229878
  • GENBANK/FJ229879
  • GENBANK/FJ229880
  • GENBANK/FJ229881
  • GENBANK/FJ229882
  • GENBANK/FJ229883
  • GENBANK/FJ229884
  • GENBANK/FJ229885
  • GENBANK/FJ229886
  • GENBANK/FJ229887
  • GENBANK/FJ229888
  • GENBANK/FJ229889
  • GENBANK/FJ229890
  • GENBANK/FJ229891
  • GENBANK/FJ229892
  • GENBANK/FJ229893
  • GENBANK/FJ229894
  • GENBANK/FJ229895
  • GENBANK/FJ229896
  • GENBANK/FJ229897
  • GENBANK/FJ229898
  • GENBANK/FJ229899
  • GENBANK/FJ229900
  • GENBANK/FJ229901
  • GENBANK/FJ229902
  • GENBANK/FJ229903
  • GENBANK/FJ229904
  • GENBANK/FJ229905
  • GENBANK/FJ966231
  • GENBANK/FJ966232
  • GENBANK/FJ966233
  • GENBANK/FJ966234
  • GENBANK/FJ966235
  • GENBANK/FJ966236
  • GENBANK/FJ966237
  • GENBANK/FJ966238
  • GENBANK/FJ966239
  • GENBANK/FJ966240
  • GENBANK/FJ966241
  • GENBANK/FJ966242