The burden and dynamics of hospital-acquired SARS-CoV-2 in England

Abstract

Hospital-based transmission played a dominant role in MERS-CoV and SARS-CoV epidemics but large-scale studies of its role in the SARS-CoV-2 pandemic are lacking. Such transmission risks spreading the virus to the most vulnerable individuals and can have wider-scale impacts through hospital-community interactions. Using data from acute hospitals in England we quantify within-hospital transmission, evaluate likely pathways of spread and factors associated with heightened transmission risk, and explore the wider dynamical consequences. We show that hospital transmission is likely to have been a major contributor to the burden of COVID-19 in England. We estimate that between June 2020 and March 2021 between 95,000 and 167,000 patients acquired SARS-CoV-2 in hospitals with nosocomially-infected patients likely to have been the main sources of transmission to other patients. Increased transmission to patients was associated with hospitals having fewer single rooms and lower heated volume per bed. Moreover, we show that reducing hospital transmission could substantially enhance the efficiency of punctuated lockdown measures in suppressing community transmission. These findings reveal the previously unrecognised scale of hospital transmission, have direct implications for targeting of hospital control measures, and highlight the need to design hospitals better-equipped to limit the transmission of future high consequence pathogens.

How have mathematical models contributed to understanding the transmission and control of SARS-CoV-2 in healthcare settings? A systematic search and review

“…During the first wave in early 2020, they have been estimated to be the most important source of onward nosocomial transmission, both to patients and other HCWs [17,18]. However, other studies found that patient infection could result primarily from transmission from other patients [4,16,18].…”

“…Both patients and healthcare workers (HCWs) have been at high risk of SARS-CoV-2 infection throughout the pandemic, resulting in major nosocomial outbreaks worldwide [1,2]. In England, for instance, an estimated 20% of patients hospitalized with COVID-19 before August 2020 acquired their infection in hospital [3], while 95,000-167,000 patients became infected during their hospital stay between June 2020 and March 2021 [4]. Further, HCWs have experienced an estimated 1.6-to 3.4-fold higher risk of infection relative to the general population [5,6].…”

Nanopore sequencing of influenza A and B in Oxfordshire and the United Kingdom, 2022-23

“…This same pattern has also been observed for SARS-CoV-2 where patients are most infectious shortly after they are initially infected, such that nosocomial cases account for much hospital-based transmission. 18,19 Focusing infection control efforts around these cases is an important priority. It should also be considered that genomically and epidemiologically linked pairs, could also represent 'co-secondary' cases, where both are acquired from a common, but unascertained source.…”

Estimating the risk of incident SARS-CoV-2 infection among healthcare workers in quarantine hospitals: the Egyptian example

“…In conclusion, the key role played by healthcare settings during pandemic waves since 2020 worldwide [21] highlights the need for innovative strategies to control the nosocomial risk. Quarantine hospitals, which effectively isolated non-COVID patients from COVID patients and allowed to closely monitor at-risk HCWs, may provide interesting solutions to this challenge.…”