Immunisation and Countermeasures Division, Public Health England, 61 Colindale Avenue, London NW9 5EQ, UK; Paediatric Infectious Diseases Research Group, St. George's University of London, UK.
London Health Protection team, National Infection Service, Public Health England, London, UK.
J Infect. 2020 Oct;81(4):621-624. doi: 10.1016/j.jinf.2020.07.027. Epub 2020 Jul 29.
Care homes have been disproportionately affected by the COVID-19 pandemic and continue to suffer large outbreaks even when community infection rates are declining, thus representing important pockets of transmission. We assessed occupational risk factors for SARS-CoV-2 infection among staff in six care homes experiencing a COVID-19 outbreak during the peak of the pandemic in London, England.
Care home staff were tested for SARS-COV-2 infection by RT-PCR and asked to report any symptoms, their contact with residents and if they worked in different care homes. Whole genome sequencing (WGS) was performed on RT-PCR positive samples.
In total, 53 (21%) of 254 staff were SARS-CoV-2 positive but only 12/53 (23%) were symptomatic. Among staff working in a single care home, SARS-CoV-2 positivity was 15% (2/13), 16% (7/45) and 18% (30/169) in those reporting no, occasional and regular contact with residents. In contrast, staff working across different care homes (14/27, 52%) had a 3.0-fold (95% CI, 1.9-4.8; P<0.001) higher risk of SARS-CoV-2 positivity than staff working in single care homes (39/227, 17%). WGS identified SARS-CoV-2 clusters involving staff only, including some that included staff working across different care homes.
SARS-CoV-2 positivity was significantly higher among staff working across different care homes than those who were working in the same care home. We found local clusters of SARS-CoV-2 infection between staff only, including those with minimal resident contact. Infection control should be extended for all contact, including those between staff, whilst on care home premises.
养老院受到 COVID-19 大流行的严重影响，即使社区感染率下降，仍持续发生大规模疫情爆发，因此代表着重要的传播点。我们评估了在英国伦敦 COVID-19 大流行高峰期期间，六家养老院中经历疫情爆发的员工中 SARS-CoV-2 感染的职业风险因素。
通过 RT-PCR 对养老院员工进行 SARS-COV-2 感染检测，并要求他们报告任何症状、与居民的接触情况以及是否在不同的养老院工作。对 RT-PCR 阳性样本进行全基因组测序（WGS）。
共有 254 名员工中的 53 名（21%）SARS-CoV-2 呈阳性，但只有 12/53 名（23%）出现症状。在同一家养老院工作的员工中，无、偶尔和经常与居民接触的员工 SARS-CoV-2 阳性率分别为 15%（2/13）、16%（7/45）和 18%（30/169）。相比之下，在不同养老院工作的员工（14/27，52%）感染 SARS-CoV-2 的风险比在同一家养老院工作的员工（39/227，17%）高 3.0 倍（95%CI，1.9-4.8；P<0.001）。WGS 确定了仅涉及员工的 SARS-CoV-2 集群，包括一些涉及跨不同养老院工作的员工。
在不同养老院工作的员工感染 SARS-CoV-2 的阳性率明显高于在同一家养老院工作的员工。我们发现员工之间存在 SARS-CoV-2 感染的本地集群，包括与居民接触极少的员工。感染控制应扩展到所有接触，包括员工之间的接触，同时在养老院场所内。
