Let’s Talk About Flurona

Influenza-coronavirus co-infections are nothing new, nor are they unexpected. Yet the word “Flurona” is making headlines as new COVID-19 cases continue to rise. But what exactly is “Flurona” and how concerned should we be?

“Flurona” is a social media buzzword describing a situation in which a single patient is diagnosed with both COVID-19 and influenza simultaneously. To clarify, Flurona is not the name of a new virus or strain of SARS-CoV-2, or some sort of combined superbug. It is also not an official diagnosis or medical term.

“Flurona” is not new, and co-infections are not unusual

As early as January 2020, shortly after the outbreak of COVID-19, a retrospective study found that 57% of the 307 patients hospitalized for COVID-19 in Wuhan, China, also tested positive for influenza. Notably, this percentage went down to 0.9% in March, likely due to the end of the classical flu season and stringent infection control during the COVID-19 pandemic.

In June 2021, a meta-analysis of eleven prevalence studies evaluated the data of a total of 3,070 patients with COVID-19. The frequency of influenza virus co-infection among patients with COVID-19 was found to be 4.5% in Asia and 0.4% from the American continent.¹

Simultaneous infections with multiple microorganisms are far from uncommon. In fact, the prevalence of viral coinfections has been identified in many studies, concluding that many patients hospitalized with influenza-like illness are in fact infected by more than one viral pathogen.² Bacterial co-infection was involved in one of every four severe or fatal cases during the 2009 influenza pandemic³, while bacterial pneumonia was thought to have caused the majority of deaths during the 1918 pandemic.⁴

The Importance of Detection and Differentiation of COVID-19 and Influenza

Viral co-infections aren’t uncommon, and more studies are needed to evaluate the exact effect of the COVID-19 and influenza co-infection in clinical outcomes.^5,6 It’s also difficult to estimate how prevalent this particular co-infection is, as cases are only detected with proper testing for both viruses – typically reserved for patients requiring hospitalization or treatment. For the majority of cases with milder symptoms, it’s unclear whether the “Flurona” phenomenon will become a larger public concern.

For the management of severe disease, on the other hand, proper testing and early medical attention are critical. Treatment could very well be impacted based on which virus you have. Respiratory panels which can test for both COVID-19 and influenza simultaneously, such as Thermo Fisher’s TaqPath^TM COVID-19 Flu A, Flu B Combo Kit, will be an important tool for healthcare providers this flu season.

In addition to determining individual instances of viral co-infection, the utilization of multiplex testing for respiratory infections is also crucial for the general detection and differentiation of disease during the forewarned Twindemic. Incredibly low flu activity was recorded during the 2020/21 season⁷, likely due to COVID-19 prevention measures such as social distancing, stay-at-home orders, school, venue, and nonessential business closure, bans on public gatherings, travel restrictions, contact tracing and quarantine. This was welcome news last year, but it comes with a few concerning implications for this year’s flu season:

Extremely limited data from last year’s influenza strains are available to inform this year’s vaccine designs, potentially lowering the overall efficacy.⁸
Record-low activity means a lower population immunity, putting us all at risk of increased disease this year.
Increased COVID-19 vaccination rates have led to easing of public health measures worldwide.⁹ Moving forward with more open social and travel policies, we can expect to see a surge of influenza infections this season.

Right now, we are in the midst of soaring COVID-19 cases in conjunction with an ongoing flu season, and the resulting overall stress on the healthcare system is a valid concern. Because it is difficult to differentiate between the two infections based on symptoms alone, healthcare providers need the tools necessary to quickly detect and differentiate infectious respiratory viruses in patients, for effective treatment plans and infection control.⁸ Multi-target assays such as Thermo Fisher’s TaqPath^TM COVID-19 Flu A, Flu B Combo Kit is an ideal solution for researchers and healthcare providers at this pivotal time.

Though “flurona” might not be live up to its media hype, viral co-infections are an important part of the story and the significance of rising influenza cases cannot be dismissed. As hospitals and researchers brace for the intersection of COVID-19 and the peak of this year’s flu season, it is critical that their diagnostic capabilities are supported by up-to-date, accurate, and effective technology.

To learn more about Thermo Fisher Scientific’s COVID-19 and flu testing options, please visit https://www.thermofisher.com/covid19flu for EUA solutions, or https://www.thermofisher.com/covid19flursv for CE-IVD solutions.

For Emergency Use Authorization (EUA) only. For prescription use only. For in vitro diagnostic use.

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