SARS-CoV-2 infection, clinical features and outcome of COVID-19 in United Kingdom nursing homes

Abstract

Objectives: To understand SARS-Co-V-2 infection and transmission in UK nursing homes in order to develop preventive strategies for protecting the frail elderly residents.

Methods: An outbreak investigation involving 394 residents and 70 staff, was carried out in 4 nursing homes affected by COVID-19 outbreaks in central London. Two point-prevalence surveys were performed one week apart where residents underwent SARS-CoV-2 testing and had relevant symptoms documented. Asymptomatic staff from three of the four homes were also offered SARS-CoV-2 testing.

Results: Overall, 26% (95% CI 22-31) of residents died over the two-month period. All-cause mortality increased by 203% (95% CI 70-336) compared with previous years. Systematic testing identified 40% (95% CI 35-46) of residents as positive for SARS-CoV-2, and of these 43% (95% CI 34-52) were asymptomatic and 18% (95% CI 11-24) had only atypical symptoms; 4% (95% CI -1 to 9) of asymptomatic staff also tested positive.

Conclusions: The SARS-CoV-2 outbreak in four UK nursing homes was associated with very high infection and mortality rates. Many residents developed either atypical or had no discernible symptoms. A number of asymptomatic staff members also tested positive, suggesting a role for regular screening of both residents and staff in mitigating future outbreaks.

Keywords: COVID-19; Care home; Coronavirus; Diagnostic testing; Nursing home; SARS-CoV-2.

Fig. 1

Timeline of COVID-19 outbreak and associated mortality. Panel A – deaths per day throughout the outbreak timeline from 1 March to 1 May 2020 in all four homes, with key dates denoted. Colours relate to the presence of COVID-19 on medical certificate of cause of death (MCCD). Homes were closed to visitors on 16 March; a limited number of tests were made available for symptomatic testing on 2 April by Public Health England; systematic testing within the outbreak investigation commenced on 15 April. Panel B – deaths per day in each nursing home separately. Dates of first positive COVID-19 test (T1) and death-certificate coded COVID-19 death (D1) in each home are shown. Panel C – cumulative number of deaths of all causes, including non-COVID-19, throughout the two-month period (red). Historic average number of deaths throughout the same period in 2018 and 2019 is shown in grey for comparison.

Fig. 2

COVID-19 Symptoms, Outcomes and Comorbidities. (A) Relationship of COVID-19 symptoms in two weeks preceding swabbing with SARS-CoV-2 test result. ‘Confusion’ refers to altered mental status or behaviour. GI symptoms refers to diarrhoea and/or vomiting. (B) Relationship of comorbidities to all-cause mortality; CVD: cardiovascular disease; CKD: chronic kidney disease; lung disease refers to chronic lung disease.

Fig. 3

Association of symptoms with a positive SARS-CoV-2 rt-PCR result. Relationship of symptom in preceding two weeks to a positive SARS-CoV-2 result in all residents tested (n = 313), displayed as adjusted odds ratios with 95% confidence intervals. Significant predictors in model indicated by ** P<0.01; *** P<0.001.

Fig. 4

SARS-CoV-2 variants in nursing homes. Maximum likelihood phylogenetic tree showing SARS-CoV-2 sequence variation across and within the four nursing homes, in the UK context, by date of sample result. The Wuhan-Hu-1 2019 reference strain is shown to the far left. Coloured dots represent the sequences originating from residents (n=18) and staff (n=1, see asterisk), alongside 400 publicly shared sequences from England, Wales, Scotland and Northern Ireland (in grey, see supplementary). Phylogenetic analysis and figure obtained using Nextstrain.