title: Surveillance for neuraminidase inhibitor resistance in human influenza viruses from Australia.
abstract: Two hundred and forty-five human influenza A and B viruses isolated in Australia between 1996 and 2003 were tested for their sensitivity to the NA inhibitor drugs, zanamivir and oseltamivir using a fluorescence-based neuraminidase inhibition assay. Based on mean IC50 values, influenza A viruses (with neuraminidase subtypes N1 and N2) were more sensitive to both the NA inhibitors than were influenza B strains. Influenza A viruses with a N1 subtype and influenza B strains both demonstrated a greater sensitivity to zanamivir than to oseltamivir carboxylate, whereas influenza A strains with a N2 subtype were more susceptible to oseltamivir carboxylate. A comparison of IC50 values for viruses isolated before and after the release of the NA inhibitors in Australia, found there was no significant difference in the sensitivity of strains to either neuraminidase inhibitor and none of the isolates tested showed clinically significant resistance.
authors.affiliation: WHO Collaborating Centre for Reference and Research on Influenza, Melbourne, Australia. Aeron_Hurt@csl.com.au
authors.forename: Aeron C
authors.initials: AC
authors.lastname: Hurt
authors.forename: Ian G
authors.initials: IG
authors.lastname: Barr
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Durrant
authors.forename: Robert P
authors.initials: RP
authors.lastname: Shaw
authors.forename: Helen M
authors.initials: HM
authors.lastname: Sjogren
authors.forename: Alan W
authors.initials: AW
authors.lastname: Hampson
mesh_terms: D000081:Acetamides / Q000494:pharmacology / Q000627:therapeutic use; D000998:Antiviral Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001315:Australia / Q000453:epidemiology; D024882:Drug Resistance, Viral; D004791:Enzyme Inhibitors / Q000494:pharmacology* / Q000627:therapeutic use; D006146:Guanidines; D006801:Humans; D009980:Influenza A virus / Q000187:drug effects* / Q000302:isolation & purification; D009981:Influenza B virus / Q000187:drug effects* / Q000302:isolation & purification; D007251:Influenza, Human / Q000188:drug therapy / Q000453:epidemiology* / Q000209:etiology; D008826:Microbial Sensitivity Tests; D009439:Neuraminidase / Q000037:antagonists & inhibitors*; D053139:Oseltamivir; D011159:Population Surveillance / Q000379:methods; D011714:Pyrans; D012794:Sialic Acids / Q000494:pharmacology / Q000627:therapeutic use; D053243:Zanamivir
chemical_list: D000081:Acetamides; D000998:Antiviral Agents; D004791:Enzyme Inhibitors; D006146:Guanidines; D011714:Pyrans; D012794:Sialic Acids; D053139:Oseltamivir; D009439:Neuraminidase; D053243:Zanamivir