- Chapman T, et al. Another aspect of COVID pandemic: where has all the Flu gone? Poster 3255. ERS 2021, 5-8 September.
- Hills T, et al. Lancet. 2020 Nov 21;396(10263):1633–1634.
There has been a dramatic reduction in cases of influenza and RSV during the COVID pandemic globally. The current study looked at the incidence of respiratory viruses in a rural district general hospital in Shrewsbury, UK, during the (supposed) peak flu season. A retrospective analysis was carried out1 on all respiratory swab data of patients in the hospital during the third and fourth week of January 2021. Respiratory analysis was done for influenza, RSV, and SARS-CoV-2 simultaneously.
A respiratory sample was taken in 247 patients and tested for all viruses. In total, 120/247 (47%) tested positive for SARS-CoV-2, of which 66 (55%) were male with a mean age of 73 years; zero tested positive for influenza A/B and RSV A/B. Although the sample size was small, this cohort reflected the trend of flu cases represented in the Southern Hemisphere during the peak flu season2.
It might be that regular hand washing and masks prevented the spread of other respiratory viruses to happen. Moreover, competitive inhibition of influenza and RSV by SARS-CoV-2 is likely through its binding of sialic acid receptors on the host’s cell surface normally used by influenza viruses to gain entry into cells. However, future studies are needed to study this in vitro.