Influenza susceptibility testing on influenza viruses was initiated in the Virology Laboratory in 2006.  The program has grown and developed substantially since its inception. A proportion of all submitted influenza positive specimens are routinely tested for resistance surveillance purposes. Aggregate results of this testing are posted weekly in the New York State Weekly Influenza Surveillance Report.  Additionally, influenza positive patients not responding to influenza antiviral therapy can be submitted for testing following consultation with the laboratory. Please contact the laboratory for approval of testing before shipping any specimens. The patient must fulfill the following initial criteria:

  • Confirmed influenza positive test results (by any method)
  • Completed a 5 day course of antiviral therapy with no clinical improvement

Other helpful information:

  • What type/subtype of influenza is the patient infected with?
  • What antiviral drug was administered?
    • start and end dates of treatment?
  • Is the patient immunocompromised?

Available Influenza Antiviral Drug Susceptibility Testing Methods

  Influenza Viruses Antiviral Drug Class Targets* Antiviral Drug Specific Mutations Detected
Pyrosequencing A/H1pdm09 and A/H3 Neuraminidase and Polymerase Inhibitors  (A/H1pdm09) I223, H275Y, (A/H3) E119, R292, N294 
Dideoxy A/H1pdm09, A/H3, and B Neuraminidase Inhibitors  All in NA Gene
Whole Genome Sequencing All influenza viruses Adamantanes and Neuraminidase Inhibitors  Not Specific
Neuraminidase Inhibition All influenza viruses Neuraminidase Inhibitors  Not Specific
Polymerase Inhibition All influenza viruses  Polymerase Inhibitors  

*FDA approved influenza antivirals

For further information on influenza anti-viral testing please contact the Team Lead Jennifer Laplante at 518-474-4177.

The CDC provides additional information on influenza antiviral drug resistance.