CDC Issues Health Advisory about Seasonal Influenza A(H3N2) Activity and Antiviral Treatment of Patients with Influenza

PUBLISHED: Dec 28, 2017
Relevant to: Ambulatory Care, Critical Access Hospitals, Home Health, Hospitals, Long Term Care, Medical Office, Pharmacy

In the United States (U.S.), influenza activity has increased significantly over recent weeks with influenza A(H3N2) viruses predominating thus far this season. In the past, A(H3N2) virus-predominant influenza seasons have been associated with more hospitalizations and deaths in persons aged 65 years and older and young children compared to other age groups. In addition, influenza vaccine effectiveness (VE) in general has been lower against A(H3N2) viruses than against influenza A(H1N1)pdm09 or influenza B viruses.

The US Centers for Disease Control and Prevention (CDC) has issued a Health Advisory that:

  • Speaks to increased influenza A (H3N2) activity and its clinical implications
  • Provides a summary of influenza antiviral drug treatment recommendations
  • Gives an update about approved treatment drugs and supply this season
  • Provides background information for patients about influenza treatment

Please see the Health Advisory, link is below, to review all of the CDC recommendations. Highlights include:

  • Antiviral medications should be used for treatment of influenza as an important adjunct to annual influenza vaccination.
  • Hospitalized, Severely Ill, and High-Risk Patients with Suspected or Confirmed Influenza Should Be Treated with Antivirals.
  • Antiviral treatment should be started as soon as possible after illness onset and should not be delayed even for a few hours to wait for the results of testing. Ideally, treatment should be initiated within 48 hours of symptom onset. However, antiviral treatment initiated later than 48 hours after illness onset can still be beneficial for some patients. Because of the importance of early treatment, decisions about starting antiviral treatment should not wait for laboratory confirmation of influenza.
  • Information to assist clinicians about influenza testing decisions is available at
  • Antiviral treatment may also be prescribed on the basis of clinical judgment for any previously healthy (non-high risk) outpatient with suspected or confirmed influenza who presents within 2 days after illness onset.
  • Three prescription neuraminidase inhibitor antiviral medications are approved by the U.S. Food and Drug Administration (FDA) and are recommended for use in the U.S. during the 2017–2018 influenza season: oseltamivir (available as a generic version or under the trade name Tamiflu®), zanamivir (Relenza®), and peramivir (Rapivab®).
  • Adamantanes (rimantadine and amantadine) are not currently recommended for antiviral treatment or chemoprophylaxis of influenza A because of high levels of resistance among circulating influenza A viruses.

Included with today’s notice are example polices related to influenza care, treatment and prevention.

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