Another aspect of COVID pandemic: where has all the Flu gone?

Abstract

Background: United Kingdom is officially in the Flu season since the beginning of October 2020. Flu season in the southern hemisphere particularly in Australia and New Zealand have shown dramatic reduction in cases of Influenza during the COVID pandemic.[1]

Aims: Our objective was to look at the incidence of Flu in our rural district general hospital, which has also been affected by the COVID pandemic.

Method: We carried out a retrospective analysis of all patients in hospital during the 3rd and 4th week of January 2021, who had a Flu swab taken. Our hospital used a kit to detect the presence of Flu A, Flu B, Respiratory Syncytial Virus(RSV) A &B and SARS-CoV2 at the same time. Data analysis was done on MS Excel.

Results: 247 patients in hospital had a swab performed for all 4 viruses. 52% were males(n=129) with a Mean Age(SD)73 (14.7) years.120 tested positive for SARS-CoV2 of which 55%(n=66) were males with a mean age(SD)73 (14.6) years. Zero tested positive for Influenza A/B and RSV A/B.

Conclusion: Our small cohort of hospital patients reflected the trend of flu cases present in the Southern Hemisphere, during peak Flu season. It is possible regular hand washing and masks donning contributed to this. In addition, competitive inhibition of the Flu virus by SARS-CoV2 is likely through its binding of sialic acid receptors on the host's cell surface, commonly used by Influenza viruses to gain entry into cells [2]. More laboratory studies are needed to confirm this.

References: 1. Hills T, et al. Influenza control during the COVID-19 pandemic. The Lancet.2020;396(10263):1633-4.

2. Bò L, et al. Exploring the association between sialic acid and SARS-CoV-2 spike protein through a molecular dynamics-based. Frontiers in medical technology.2020;2:24