Investigation of hospital discharge cases and SARS-CoV-2 introduction into Lothian care homes.

BACKGROUND: The first epidemic wave of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in Scotland resulted in high case numbers and mortality in care homes. In Lothian, over a third of care homes reported an outbreak while there was limited testing of hospital patients discharged to care homes.

AIM: Investigate hospital discharges as a source of SARS-CoV-2 introduction into care homes during the first epidemic wave.

METHODS: A clinical review was performed for all discharges from hospitals to care homes starting 1st March 2020 to 31st May 2020. Episodes were ruled out based on coronavirus disease (COVID-19) test history, clinical assessment at discharge, whole genome sequencing (WGS) data and an infectious period of 14 days. Clinical samples were processed for WGS, and consensus genomes generated were used for analysis by cluster investigation and virus epidemiological tool (CIVET). Patient timelines were obtained using electronic hospital records.

FINDINGS: In total 787 hospital discharges to care homes were identified. Out of these 776 (99%) were ruled out for hospital discharge introduction. However, for 10 episodes the results were inconclusive as there was low genomic diversity in consensus genomes or no sequencing data. Only one discharge episode had a genomic, time and location link to positive cases during hospital admission leading to 10 further positive cases in the care home.

CONCLUSION: Majority of hospital discharges were ruled out for introduction into Lothian care homes highlighting the importance of screening all new admissions when faced with a novel emerging virus and no vaccine available.