Fast Five Quiz: Influenza Practice Essentials

Michael Stuart Bronze, MD


November 03, 2021

Guidelines from the Infectious Diseases Society of America (IDSA) recommend the following:

  • Clinicians should use rapid molecular assays (ie, nucleic acid amplification tests) over rapid influenza diagnostic tests in outpatients to improve detection of influenza virus infection.

  • Clinicians should use reverse-transcription polymerase chain reaction or other molecular assays over other influenza tests in hospitalized patients to improve detection of influenza virus infection.

  • Nasopharyngeal specimens should be collected over other upper respiratory tract specimens to increase detection of influenza viruses. If nasopharyngeal specimens are not available, nasal and throat swab specimens should be collected and combined for testing over single specimens from either site. Mid-turbinate nasal swab specimens should be collected over throat swab specimens.

  • Clinicians should not collect or routinely test for influenza specimens from nonrespiratory sites such as blood, plasma, serum, cerebrospinal fluid, urine, and stool.

Rapid influenza diagnostic tests can directly detect influenza A or B virus-associated antigens or enzyme in throat swabs, nasal swabs, or nasal washes. These tests can produce results within 30 minutes. A meta-analysis examining the accuracy of rapid influenza diagnostic tests found that these tests tended to be more sensitive in children (67%) than in adults (54%) and were better at detecting influenza A (65%) than influenza B (52%).

Read more on the workup of influenza.


Comments on Medscape are moderated and should be professional in tone and on topic. You must declare any conflicts of interest related to your comments and responses. Please see our Commenting Guide for further information. We reserve the right to remove posts at our sole discretion.