Influenza Clinical Management

These materials include updated recommendations form the New York City Health Department and from the Centers for Disease Control and Prevention (CDC) regarding clinical management of patients with suspected or confirmed influenza during the 2013-14 influenza season. Decisions regarding clinical management of patients should be based on local current surveillance data, patient underlying risk conditions, and severity of illness. In most cases, laboratory diagnostic testing to distinguish whether a patient has influenza or which type or subtype, will not be available in time for clinical decisions. Clinical judgment should always be used. Please consult information on vaccination.

Key points

When influenza is circulating in the community:

  • Use local current surveillance data to guide your decision-making.
  • Most cases of influenza are mild. Patients can be managed either in the outpatient setting or over the telephone. Patients with mild influenza-like illness* (ILI) who do not fall into a high risk group for severe illness and complications due to influenza generally do NOT require antiviral medication.
  • Patients who are in high risk groups should be treated with antiviral medications if they develop ILI when influenza is circulating.
  • Early empiric treatment of ILI with antiviral medications (ideally within 48 hours of illness onset) is recommended for:
    • Patients with severe illness, including those being hospitalized for unexplained acute febrile respiratory illness.
    • Patients with mild ILI in high risk groups.

* Influenza-like illness (ILI) is defined as fever ≥ 100°F (≥ 37.8°C) with cough and/or sore throat

See more information: general clinical management.

Treatment and Prophylaxis

Early empiric treatment of ILI (ideally within 48 hours of onset) is recommended for people with severe symptoms, hospitalized patients and those with underlying conditions increasing the risk of complications and severe illness. Treatment may be beneficial even if initiated after 48 hours post-onset. All patients being hospitalized for suspected or confirmed influenza should be treated, regardless of time since onset. Currently, oseltamivir or zanamavir are the drugs of choice to treat suspected or confirmed influenza.

See more information: antiviral treatment and prophylaxis.

Diagnostic Testing

Diagnostic testing for influenza is generally not necessary for most patients with mild influenza-like illness.

  • Commercially available rapid test kits (EIA) have poor sensitivity for detecting influenza. A positive result is indicative of infection but a negative result should not be used to rule out influenza.
  • Other, more sensitive, assays including RT-PCR for subtyping of influenza A are available commercially but are not available at the point of care. Results of these tests may not be back within 48 hours of illness onset (i.e., in time for treatment decisions).
  • The NYC Public Health Laboratory is not accepting individual specimens for influenza diagnostic testing except as part of ongoing surveillance programs.

See more information: