Influenza Diagnostic Tests (M00126)

To avoid the overuse of antibiotics and the potential risk of antibiotic resistance, point of care providers should test patients prior to prescribing treatment for a bacterial or influenza infection. The following summary provides a list of the main available types of diagnostics tests:

Rapid Antigen Tests:

  • Available at the point of care
  • Yields a Flu A and Flu B result in < 30 minutes
  • Less sensitive (50-70%) and specific (90-95%) compared to other methods and may require confirmation with another method
  • CDC recommendation:
    • During early winter months, providers should confirm negative rapid flu test results with a more sensitive method, such as viral culture or a nucleic acid amplification test (NAAT)
    • Outside of flu season, providers should consider confirming positive rapid flu test results

Targeted Molecular Methods:

  • Uses transcriptase-polymerase chain reaction (RT-PCR) or isothermal amplification methods to detect viral nucleic acids
  • Results available in < 24 hours
  • Detects from 1-2 to up to 20 respiratory pathogens from one specimen

Viral Culture: 

  • Confirms present active infection
  • Results available in 3-10 days
  • Misses opportunity for Tamiflu treatment for positive patients 

Test Selection:
During flu season and following preliminary patient examination and assessment of risk factors, providers should consider a targeted diagnostic evaluation to rule out influenza before ordering a larger respiratory virus panel, particularly if there is a high likelihood that the patient has flu (or RSV).