COVID-19 testing in outbreak free care homes: What are the public health benefits?

BACKGROUND: COVID-19 care home outbreaks represent a significant proportion of COVID-19 morbidity and mortality in the UK. National testing initially focused on symptomatic care home residents, before extending to asymptomatic cohorts.

AIM: The aim was to describe the epidemiology and transmission of COVID-19 in outbreak free care homes.

METHODS: A two-point prevalence survey of COVID-19, in 34 Liverpool care homes, was performed in April and May 2020. Changes in prevalence were analysed. Associations between care home characteristics, reported infection, prevention and control interventions, and COVID-19 status were described and analysed.

FINDINGS: No resident developed COVID-19 symptoms during the study. There was no significant difference between: the number of care homes containing at least one test positive resident between the first (17.6%, 95%CI 6.8-34.5) and second round (14.7%, 95%CI 5.0-31.1) of testing (p>0.99); and the number of residents testing positive between the first (2.1%, 95%CI 1.2-3.4) and second round (1.0%, 95%CI 0.5-2.1) of testing (p=0.11). Care homes providing nursing care (RR 7.99, 95%CI 1.1-57.3) and employing agency staff (RR 8.4, 95%CI 1.2-60.8) were more likely to contain test positive residents. Closing residents shared space was not associated with residents testing positive (RR 2.63, 95%CI 0.4-18.5).

CONCLUSIONS: Asymptomatic COVID-19 care homes showed no evidence of disease transmission or development of outbreaks; suggesting that current infection prevention and control measures are effective in preventing transmission. Repeat testing at 2-3 weeks had limited or no public health benefits over regular daily monitoring of staff and residents for symptoms. These results should inform policies calling for regular testing of asymptomatic residents.