Survey of Influenza and Other Respiratory Viruses Diagnostic Testing in US Hospitals, 2012–2013

Su Su; Alicia M. Fry; Pam Daily Kirley; Deborah Aragon; Kimberly Yousey-Hindes; James Meek; Kyle Openo; Oluwakemi Oni; Ruta Sharangpani; Craig Morin; Gary Hollick; Krista Lung; Matt Laidler; Mary Lou Lindegren; William Schaffner; Annette Atkinson; Sandra S. Chaves

Disclosures

Influenza Resp Viruses. 2016;30(2):86-90. 

In This Article

Discussion

We demonstrated predominant use of rapid diagnostic tests for influenza and RSV during 2012–2013 among hospitals and laboratories from 15 states. While the use of molecular diagnostic assays for detection of influenza virus infection at hospital and associated commercial laboratories increased modestly since 2006–2007, the availability of influenza molecular diagnostics for clinical care at hospitals was still limited; only 26% of hospital laboratories reported availability of molecular diagnostic assays. Laboratory diagnostics for respiratory viruses other than influenza and RSV were uncommonly available. Also, a minority of hospitals included in our survey had policies in place to systematically test patients with acute respiratory infections (ARI) seen in the ED with influenza diagnostics during influenza season. As the number and type of commercially available laboratory diagnostics for respiratory pathogens evolve, an updated survey is warranted.

We showed that in most (67%) hospitals included in FluSurv-NET, a U.S. population-based surveillance network involving 15 states, RIDT was the clinician's primary or only option for influenza diagnostic testing. RIDTs are easy to use and have rapid turnaround time for results. However, RIDTs have been shown to have suboptimal sensitivity (40–70%) compared to RT-PCR or viral culture.[10–13] Several studies suggest that healthcare providers are more likely to prescribe antiviral drugs with a positive RIDTs.[13,14] Therefore, a false-negative result may affect clinicians' decision to provide appropriate treatment and infection control among patients with influenza. Given the suboptimal sensitivity of RIDT, patient management should not depend upon a positive RIDT result. If patient management depends upon a diagnosis (or rule out) of influenza, additional confirmatory test with a more sensitive assay is warranted and the initiation of antiviral treatment and implementation of infection control should be started empirically and not delayed while awaiting confirmation.[15] In our survey, only 31% of laboratories had protocols for confirmatory testing with a more sensitive assay following a negative rapid test result. This may reflect the limited usefulness of receiving testing results late in clinical care. Also, in our survey, the laboratories confirming RIDT test results reflects shipment of specimens to state public health laboratories as part of FluSurv-NET surveillance, in addition to clinician practice. New molecular assays may improve the accuracy of influenza diagnosis, but timeliness and cost of these new assays could affect future use.

Our survey has some limitations. The survey was completed in 2012–2013 and may not be representative of laboratories in more recent seasons, especially in light of expanding commercially available molecular assays, and may not be representative of all hospital laboratories in United States. Hospitals in the FluSurv-NET catchment area have regular correspondence with state health department and may have better access to laboratory diagnostics than elsewhere, and physicians in these settings may be more aware of the importance of early diagnosis of influenza and other viral pathogens. Nonetheless, it provided an overview of local laboratory capacity in the nation as it reflected over 260 hospitals of varying characteristics and 240 supporting laboratories. Finally, the hospital laboratories that did not respond to our survey provide few cases to FluSurv-NET and may be different from the participating laboratories.

In conclusion, our survey suggests that most hospitals in the United States in 2012–2013 were heavily dependent on RIDT to diagnose influenza. Reliance upon an insensitive assay may compromise patient treatment and infection control. Increasing use of molecular assays for respiratory viruses may improve patient care and surveillance for respiratory viruses.

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