key: cord-0938395-z2rstfm3
authors: Bramley, Alexandra; Crocker-Buque, Tim; Breuer, Judith; Mahungu, Tabitha W
title: Evidence of the reduction of acute circulating communicable viruses during the SARS-CoV-2 pandemic in London.
date: 2021-08-20
journal: J Infect
DOI: 10.1016/j.jinf.2021.08.029
sha: 242aeaead4d4431294ab01801dc1cdc0ae0c0f44
doc_id: 938395
cord_uid: z2rstfm3

nan

there was an 87.5% reduction in positive tests for gastrointestinal viruses at RFH and GOSH (585 vs. 73; Figure 1 ) and a 62.2% reduction in paediatric respiratory viruses at GOSH (2381 vs. 899; Figure   2 ). We observed 53.8% reduction in varicella at RFH (65 vs. 30), with the mean monthly number of 2 cases being 5.4 pre-pandemic and 2.7 during the pandemic. There was also a 98.8% reduction in respiratory viruses at RFH (969 vs. 12), however due to the pandemic, demand management of all RT-PCR tests was implemented from October 2020, limiting direct comparisons.

Further analysis is needed to infer causality however the markedly shorter and less severe flu influenza epidemic and rapid decline in respiratory viruses coincide with the introduction of the wide range of non-pharmaceutical public health interventions (NPI) such as: movement restrictions, social distancing, face coverings and increased personal hygiene. 2 It's also possible that the introduction of restrictions including the reduction in global travel may have a part to play. There is also the question of viral interference during a pandemic. However, the evidence we present here suggests the COVID-19 pandemic has had a profound effect on circulating varicella, gastrointestinal, respiratory viruses in the populations covered by two large hospitals in London.

These findings support the growing evidence base covering a range of localities around the world.

Data from the WHO Global Influenza Surveillance and Response system shows that across countries in the Southern Hemisphere there has been little Influenza activity since mid-April 2020, despite increased testing in some countries. 3 In the UK, Public Health England (PHE) have also reported that circulating seasonal respiratory viruses, other than SARS-CoV-2 was similar overall compared to levels reported in recent years with lower levels of Respiratory Syncytial Virus (RSV) seen than in previous seasons in England. 4 A significant reduction in RSV cases have also been shown in Australia. 5 In one area of the UK, rhinovirus detection in adults admitted to hospital was significantly lower in summer 2020 compared to 2019, however this increased once schools reopened in September 2020. 6 There is also evidence of reduced circulation of enteric viruses. PHE has reported an 89% reduction in reported cases of norovirus and rotavirus during the seasons affected by the pandemic, when compared to the average of 2015-2020 seasons. 7 A German study has shown an almost complete 3 reduction in positive norovirus tests; 8 and an Australian study demonstrated an 84.2% reduction in enterovirus detection. 9 The decrease in varicella cases may lead to potential increases in complications as older children will still be susceptible, as well as a potential rise in cases due to the reduction in boosting of adults with varicella exposure.

These findings are unprecedented and likely to be similar for other transmissible viruses for which data are not routinely collected. Taken together, these data suggest that there is likely to have been a build-up in numbers of children and adults susceptible to these common infections with potential for epidemics to occur following easing of lockdown. We suggest that there is a need for modelling to better understand the possible impact on healthcare services. 

SARS-CoV-2 has displaced other seasonal respiratory viruses: Results from a prospective cohort study

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Decreased Influenza Activity During the COVID-19 Pandemic -United States

PHE. Surveillance of influenza and other respiratory viruses in the UK. Winter 2019 to 2020. PHE publications gateway number

COVID-19 public health measures and respiratory syncytial virus

Physical distancing in schools for SARS-CoV-2 and the resurgence of rhinovirus

Potential future implications of the COVID-19 pandemic on Norovirus infections in England

Decrease in norovirus infections in Germany following COVID-19 containment measures

Decreased incidence of enterovirus and norovirus infections during the COVID-19 pandemic