Background
COVID-19 outbreaks are still occurring in English care homes despite the non-pharmaceutical
interventions (NPIs) in place.
Methods
We developed a stochastic compartmental model to simulate the spread of SARS-CoV-2 within
an English care home. We quantified the outbreak risk under the NPIs already in place, the role
of community prevalence in driving outbreaks, and the relative contribution of all importation
routes into the care home. We also considered the potential impact of additional control
measures, namely: increasing staff and resident testing frequency, using lateral flow antigen
testing (LFD) tests instead of PCR, enhancing infection prevention and control (IPC), increasing
the proportion of residents isolated, shortening the delay to isolation, improving the
effectiveness of isolation, restricting visitors and limiting staff to working in one care home.
Findings
The model suggests that importation of SARS-CoV-2 by staff, from the community, is the main
driver of outbreaks, that importation by visitors or from hospitals is rare, and that the past testing
strategy (monthly testing of residents and daily testing of staff by PCR) likely provides negligible
benefit in preventing outbreaks. Daily staff testing by LFD was 39% (95% 18-55%) effective in
preventing outbreaks at 30 days compared to no testing.
Interpretation
Increasing the frequency of testing in staff and enhancing IPC are important to preventing
importations to the care home. Further work is needed to understand the impact of vaccination
in this population, which is likely to be very effective in preventing outbreaks.
Funding
The National Institute for Health Research, European Union Horizon 2020, Canadian Institutes
of Health Research, French National Research Agency, UK Medical Research Council. The
World Health Organisation funded the development of the COS-LTCF Shiny application.
Biomedical and health research: an analysis of country participation and research fields in the EU’s Horizon 2020