학술논문
Investigation of SARS-CoV-2 outbreaks in six care homes in London, April 2020
Document Type
article
Author
Shamez N Ladhani; J.Yimmy Chow; Roshni Janarthanan; Jonathan Fok; Emma Crawley-Boevey; Amoolya Vusirikala; Elena Fernandez; Marina Sanchez Perez; Suzanne Tang; Kate Dun-Campbell; Edward Wynne- Evans; Anita Bell; Bharat Patel; Zahin Amin-Chowdhury; Felicity Aiano; Karthik Paranthaman; Thomas Ma; Maria Saavedra-Campos; Richard Myers; Joanna Ellis; Angie Lackenby; Robin Gopal; Monika Patel; Colin Brown; Meera Chand; Kevin Brown; Mary E Ramsay; Susan Hopkins; Nandini Shetty; Maria Zambon
Source
EClinicalMedicine, Vol 26, Iss , Pp 100533- (2020)
Subject
Language
English
ISSN
2589-5370
Abstract
Background: Care homes are experiencing large outbreaks of COVID-19 associated with high case-fatality rates. We conducted detailed investigations in six London care homes reporting suspected COVID-19 outbreaks during April 2020.Methods: Residents and staff had nasal swabs for SARS CoV-2 testing using RT-PCR and were followed-up for 14 days. They were categorized as symptomatic, post-symptomatic or pre-symptomatic if they had symptoms at the time of testing, in the two weeks before or two weeks after testing, respectively, or asymptomatic throughout. Virus isolation and whole genome sequencing (WGS) was also performed.Findings: Across the six care homes, 105/264 (39.8%) residents were SARS CoV-2 positive, including 28 (26.7%) symptomatic, 10 (9.5%) post-symptomatic, 21 (20.0%) pre-symptomatic and 46 (43.8%) who remained asymptomatic. Case-fatality at 14-day follow-up was highest among symptomatic SARS-CoV-2 positive residents (10/28, 35.7%) compared to asymptomatic (2/46, 4.3%), post-symptomatic (2/10, 20.0%) or pre-symptomatic (3/21,14.3%) residents. Among staff, 53/254 (20.9%) were SARS-CoV-2 positive and 26/53 (49.1%) remained asymptomatic. RT-PCR cycle-thresholds and live-virus recovery were similar between symptomatic/asymptomatic residents/staff. Higher RT-PCR cycle threshold values (lower virus load) samples were associated with exponentially decreasing ability to recover infectious virus (P