Influenza: Fact or Fallacy?

Clinician Misperceptions Related to Influenza Testing and Treatment

Erin Burns, MA; Alicia Fry, MD


January 23, 2014

Editorial Collaboration

Medscape &

In This Article

Misperceptions About Testing and Treatment of Influenza

Many clinicians hold misperceptions about influenza testing and treatment. This article will identify a few of the more common myths surrounding this topic, which have been identified through Centers for Disease Control and Prevention (CDC) formative research with clinicians, including in-depth-interviews.

Myth: Rapid Influenza Diagnostics Are Very Accurate

Fact. Although commercially available rapid influenza diagnostic tests (RIDTs) that detect influenza virus nucleoprotein antigen are widely used in clinical practice for diagnosing influenza because they are simple to use and provide results within 15 minutes, evaluations of these RIDTs have shown variable performance. An evaluation of RIDTs available before the 2009 pandemic reported sensitivities ranging from 27% to 61% when compared with real-time reverse transcription–polymerase chain reaction (PCR) testing.

The November 2, 2012, issue of Morbidity and Mortality Weekly Report (MMWR)[1] described an evaluation of 11 US Food and Drug Administration (FDA)-cleared RIDTs, using 23 recently circulating influenza viruses under identical conditions in a laboratory setting to assess potential shortfalls in performance. Sensitivity of RIDTs continues to vary. Although most of the recently evaluated RIDTs detected viral antigens in samples with the highest influenza virus concentrations, detection varied by virus type and influenza A virus subtype at lower concentrations.

Clinicians and laboratorians should be aware of the limitations of RIDTs and use them cautiously for diagnostic, treatment, and infection control decisions in clinical settings. Positive test results are generally reliable. However, negative RIDT test results do not exclude influenza virus infection in patients with signs and symptoms suggestive of influenza. Therefore, antiviral treatment, if indicated, should not be withheld from patients with suspected influenza because they have a negative RIDT test result.

Clinicians and laboratorians can take measures to improve detection of influenza, such as:

Collecting specimens early in the course of illness;

Ensuring that the appropriate type and highest quality of respiratory specimen is collected; and

Using the current local prevalence of influenza activity in the community to raise or lower the suspicion of influenza and to assess the benefit of testing.

Since 2009 particularly, CDC has been engaged in an ongoing initiative to improve the clinical use and performance of RIDTs in the United States. In addition to reviewing the performance of 11 RIDTs, the November 2, 2012, MMWR established a methodology for routine evaluation of RIDTs.

Other products related to this initiative include instructional videos on specimen collection as well as a free continuing education (CE) course titled "Strategies for Improving Rapid Influenza Testing in Ambulatory Settings (SIRAS)" for physicians, physician assistants, and registered nurses. The CE course and the instructional videos were developed as part of a cooperative agreement between CDC and The Joint Commission, which is an independent, not-for-profit organization that accredits and certifies more than 19,000 healthcare organizations and programs in the United States.