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 VirusesAntiviral Drug Class Targets*Antiviral Drug Specific Mutations Detected
PyrosequencingA/H1pdm09 and A/H3Neuraminidase and Polymerase Inhibitors (A/H1pdm09) I223, H275Y, (A/H3) E119, R292, N294 
DideoxyA/H1pdm09, A/H3, and BNeuraminidase Inhibitors All in NA Gene
Whole Genome SequencingAll influenza virusesAdamantanes and Neuraminidase Inhibitors Not Specific
Neuraminidase InhibitionAll influenza virusesNeuraminidase Inhibitors Not Specific
Polymerase InhibitionAll 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.