"Flurona" co-infection increases the risk of severe illness and death
Worse outcomes for patients infected with COVID-19 and influenza highlight the importance of vaccination against both diseases.
- 28 March 2022
- 3 min read
- by Linda Geddes
Adults who are infected with both COVID-19 and influenza while in hospital are at greater risk of severe disease and death compared with those who have COVID-19 alone, or are co-infected with a different virus.
A study published in The Lancet found that those with COVID-19 and flu were four times more likely to require breathing support and 2.4 times more likely to die – highlighting the importance of vaccination against both diseases, and the need to test patients for them upon admission to hospital.
Co-infections with respiratory viruses are more likely to occur as public health restrictions are lifted, meaning hospitals should be prepared for higher rates of admissions and greater demand for intensive care beds – particularly during the winter months and severe flu seasons.
What did the study do?
Various countries have reported cases of patients with so-called “Flurona” – the unlucky combination of flu and COVID-19 in the same individual at the same time – but it was unclear if they were at any greater risk of severe illness than people who had either infection alone.
To investigate, Dr Maaike Swets and colleagues at the University of Edinburgh, UK, analysed data from 305,000 UK patients who were hospitalised with COVID-19 between 6 February 2020 and 8 December 2021. Of the 6,965 who were tested for additional respiratory viruses, 583 (8·4%) were co-infected with either influenza, respiratory syncytial virus (RSV), or adenovirus (a cause of the common cold).
What did it find?
Those patients who had COVID-19 and influenza at the same time experienced significantly worse disease, compared to those who just had COVID-19: They were four times as likely to receive mechanical ventilation, and were 2.35 times more likely to die.
Study co-author Prof Calum Semple at the University of Liverpool, UK said: “We were surprised that the risk of death more than doubled when people were infected by both flu and COVID-19 viruses. It is now very important that people get fully vaccinated and boosted against both viruses, and not leave it until it is too late.”
Have you read?
The study also found that those co-infected with adenovirus and SARS-CoV-2 were 1.53 times more likely to die, compared with those who had COVID-19 alone.
What are the implications?
Co-infections with respiratory viruses are more likely to occur as public health restrictions are lifted, meaning hospitals should be prepared for higher rates of admissions and greater demand for intensive care beds – particularly during the winter months and severe flu seasons.
Since effective vaccines for both COVID-19 and influenza exist, it is important that people take up the offer of vaccination, to reduce their individual risk and pressure on healthcare systems.
These results also highlight the importance of testing for influenza viruses in hospital patients who are admitted with COVID-19, both to identify those at greater risk of severe disease, and to guide how they are treated, because they may respond differently to antiviral drugs and those given to suppress the immune response to COVID-19.
