Disease of influenza virus and SARS‐CoV‐2 coinfection: Flurona or Flucovid?

Abstract

To the Editor, Recently, the new term Flurona has emerged to describe coinfection of influenza virus and SARS-CoV-2, causing flu, and COVID-19, respectively. 1 This terminology, however, seems to suggest a recombinant virus with genes from both influenza virus and coronavirus, like Delmicron with gene fragments from SARS-CoV-2 variants Delta and Omicron. Indeed, Delmicron and Flurona were listed in parallel in the titles of some publications, and Flurona was hinted as "a new variant" in the header of some news reports.Instead, we propose the more precise term Flucovid which is indicated by a disease having syndromes of both flu and COVID-19, such as fever, cough, fatigue, headache, shortness of breath, and loss of taste or smell, but not those of cold, for example, sneezing, running or stuffy nose, and sore throat (Figure 1). In general, the patients with Flucovid are tested positive for both influenza virus and SARS-CoV-2.Results from a meta-analysis of 54 related publications indicated an overall proportion of coinfection with influenza viruses in SARS-CoV-2-positive patients of 0.7%. 2 An over 18-month period study with 17,011 adults with SARS-CoV-2 infection shows 1.3% of coinfection with influenza viruses. 3 However, the actual coinfection rate may be much higher in that some coinfected patients may have undetectable influenza virus at the time SARS-CoV-2 infection is diagnosed. This happens because the mean incubation and viral shedding times of influenza viruses (2 and 3 days, respectively) are much shorter than those of SARS-CoV-2 (6 and 17 days, respectively). 2 The proportion of coinfection with influenza virus and SARS-CoV-2 among children (3.2%) was remarkably higher than that in adult patients (0.3%), indicating that children are more susceptible to the coinfection. The proportion of coinfection with influenza viruses among critically ill COVID-19 patients (2.2%) was higher than that in overall patients (0.6%), suggesting that coinfection with influenza viruses may aggravate the severity of Indeed, animal studies have shown that simultaneous, or sequential, coinfection by influenza A virus (IAV) and SARS-CoV-2 resulted in more severe weight loss and lung inflammatory damage, as well as increased tissue cytokine/chemokine expression than infection by either IAV or SARS-CoV-2 alone. 4 These findings suggest that coinfection of AIV and SARS-CoV-2 may also result in more severe disease in human as described above.Treating Flucovid by combining such anti-influenza drugs as Tamiflu and such anti-COVID-19 drugs as Paxlovid is

Rapid and universal detection of SARS‐CoV‐2 and influenza A virus using a reusable dual‐channel optic fiber immunosensor

“…Many case reports show that, compared with a single virus infection, coinfection with SARS‐CoV‐2 and FluA leads to a rapid development of more serious clinical symptoms. 4 In fact, in vivo experiments have shown that FluA infection increases the susceptibility of cells to SARS‐CoV‐2 infection. 5 Thus, rapid and sensitive differentiation between SARS‐CoV‐2 and FluA infections has important implications for the management and treatment of patients with influenza‐like illness.…”

“…Moreover, the overlapping seasons of the SARS‐CoV‐2 pandemic and FluA epidemic may expose a large number of people to an increased risk of simultaneous infection with both viruses. Many case reports show that, compared with a single virus infection, coinfection with SARS‐CoV‐2 and FluA leads to a rapid development of more serious clinical symptoms 4 . In fact, in vivo experiments have shown that FluA infection increases the susceptibility of cells to SARS‐CoV‐2 infection 5 .…”

SARS-CoV-2 N protein enhances the anti-apoptotic activity of MCL-1 to promote viral replication

“…The results showed that IAV infection enhanced SARS-CoV-2 infection by promoting ACE2 expression. 33 , 51 , 52 However, the effects of SARS-CoV-2 on IAV infection remain unknown. Here, we showed that N promoted IAV replication but was repressed by MCL-1 knock-down or S63845 administration.…”

Development of a multi‐recombinase polymerase amplification assay for rapid identification of COVID‐19, influenza A and B

“…What's more serious is that the mixed infection of SARS‐CoV‐2 and influenza A or B has caused great trouble to clinical diagnosis and treatment. The susceptibility of COVID‐19 in influenza‐infected people is enhanced, and the condition of mixed infection of COVID‐19 is aggravated, which is easy to develop into severe pneumonia in the present work 28,29 . We developed a more convenient and faster method for detecting SARS‐CoV‐2, H1N1, H3N2, and influenza B based on recombinase polymerase amplification (RPA) technology.…”

“…The susceptibility of COVID‐19 in influenza‐infected people is enhanced, and the condition of mixed infection of COVID‐19 is aggravated, which is easy to develop into severe pneumonia in the present work. 28 , 29 We developed a more convenient and faster method for detecting SARS‐CoV‐2, H1N1, H3N2, and influenza B based on recombinase polymerase amplification (RPA) technology. In our study, N, E and ORF1ab genes of SARS‐CoV‐2 and genes encoding the matrix protein (M) for H1N1, and the hemagglutinin (HA) for H3N2, and the polymerase A (PA) for Influenza B were selected and specific primers were designed.…”