A Study of Universal Severe Acute Respiratory Syndrome Coronavirus 2 RNA Testing Among Residents and Staff in a Large Group of Care Homes in South London

J Infect Dis. 2021 Feb 13;223(3):381-388. doi: 10.1093/infdis/jiaa565.


Background: Care homes have experienced a high number of coronavirus disease 2019 (COVID-19)-related deaths among residents since the onset of the pandemic. However, up to May 2020, there has been a lack of information about the extent of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among residents and staff in care homes and limited testing in this setting.

Methods: Combined nose and throat swab testing for SARS-CoV-2 RNA was carried out in 2455 residents and staff across 37 care homes in the London Borough of Bromley across a 3-week period. Results were reported within 24 hours of sample delivery, and data were collected on the presence or absence of symptoms.

Results: Overall, the point prevalence of SARS-CoV-2 infection was 6.5%, with a higher rate in residents (9.0%) than in staff (4.7%). A key finding was the high proportion of asymptomatic infection detected in staff (69%) and residents (51%), with evidence of underdetection of symptoms by care home staff.

Conclusions: The high proportion of asymptomatic infection combined with underdetection of symptoms by care home staff indicates that offering a test to all residents and staff in care homes with rapid reporting of results would assist accurate identification of infected individuals, facilitating prompt infection prevention and control action.

Keywords: COVID-19; Coronavirus; SARS-CoV-2; care homes; diagnostic testing.

MeSH terms

  • Adolescent
  • Adult
  • Aged
  • Aged, 80 and over
  • Asymptomatic Infections / epidemiology
  • COVID-19 / diagnosis
  • COVID-19 / epidemiology
  • COVID-19 / virology*
  • COVID-19 Testing / methods
  • Female
  • Homes for the Aged / statistics & numerical data*
  • Humans
  • London / epidemiology
  • Male
  • Middle Aged
  • Pandemics
  • Prevalence
  • RNA, Viral / genetics*
  • RNA, Viral / isolation & purification
  • SARS-CoV-2 / genetics*
  • SARS-CoV-2 / isolation & purification
  • Young Adult


  • RNA, Viral