Clinical Edge

Summaries of Must-Read Clinical Literature, Guidelines, and FDA Actions

Seasonal Influenza A & Antiviral Tx for Patients

CDC Health Advisory; 2017 Dec 27; CDC

The Centers for Disease Control and Prevention (CDC) has issued a notice regarding increased influenza A(H3N2) activity and its clinical implications, a summary of influenza antiviral drug treatment recommendations, an update about approved treatment drugs and supply for the 2017-2018 season, and background information for patients about influenza treatment. Recommendations include:

  • CDC recommends antiviral medications for the treatment of influenza as an important adjunct to annual influenza vaccination.
  • All hospitalized, severely ill, and high-risk patients with suspected 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.
  • The most accurate influenza tests are molecular assays.
  • Neuraminidase inhibitors can benefit other individuals with influenza. Three prescription neuraminidase inhibitor antiviral medications are recommended for use the US during the 2017-2018 season: iseltamivir (Tamiflu), zanamivir (Relenza), and peramivir (Rapivab).
  • Additional considerations for clinicians include bacterial infections and adverse events with antiviral use.


Centers for Disease Control and Prevention. Seasonal influenza A(H3N2) activity and antiviral treatment of patients with influenza. December 27, 2017. Accessed December 30, 2017.


The CDC announced that the predominant circulating influenza virus this year is influenza A(H3N2). In general vaccine effectiveness in the past has been lower against A(H3N2) viruses than against influenza A(H1N1), and in the past the vaccine was only approximately 30% effective in protecting against A(H3N2). This means that the use of antiviral therapy for high-risk patients may be particularly important during this year’s flu outbreak. High risk individuals include:

  • Adults aged 65 years and older.
  • Persons with chronic pulmonary (including asthma), cardiovascular (except hypertension alone), renal, hepatic, hematological (including sickle cell disease), and metabolic disorders (including diabetes mellitus), or neurologic and neurodevelopment conditions (including disorders of the brain, spinal cord, peripheral nerve, and muscle such as cerebral palsy).
  • Epilepsy, stroke, intellectual disability [mental retardation], moderate to severe developmental delay, muscular dystrophy, or spinal cord injury.
  • People with immunosuppression, including that caused by medications or by HIV infection.

  • Women who are pregnant or postpartum (within 2 weeks after delivery). 

  • People aged younger than 19 years who are receiving long-term aspirin therapy. 

  • American Indians/Alaska Natives.
  • People with extreme obesity (ie, body-mass index ≥ 40).
  • Residents of nursing homes and other chronic-care facilities. 

  • Individuals hospitalized with flu-like illness, or with severe, complicated, or progressive flu-like illness. — Neil Skolnik, MD