Increased risk of SARS-CoV-2 infection in staff working across different care homes: enhanced CoVID-19 outbreak investigations in London care Homes

Abstract

Background: Care homes have been disproportionately affected by the COVID-19 pandemic and continue to suffer lar ge 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. Methods: 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. Results: 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. Conclusions: 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.

SARS-CoV-2 Exposure and Infection Among Health Care Personnel — Minnesota, March 6–July 11, 2020

“…Congregate living or long-term care facilities often experience PPE shortages and chronic staffing shortages, and workers frequently lack formal training in infection prevention and control practices (6). HCP working in multiple long-term care facilities have been shown to be at higher risk for infection (7). The disparate exposure risks identified by MDH through HCP risk assessment and monitoring highlight a need for consistent PPE access and infection prevention and control training, especially in congregate living and long-term care settings.…”

Clinical Presentation, Course, and Risk Factors Associated with Mortality in a Severe Outbreak of COVID-19 in Rhode Island, USA, April–June 2020

“…While the facility itself was able to implement strict mitigation policies, including restriction of visitors, staff were routinely coming in from the community. Furthermore, staff members might be more likely to present as asymptomatic cases than nursing home residents [ 13 , 33 , 34 ]. While analysis of staff transmission was beyond the scope of this study, staff infection was identified as a strong risk factor for resident mortality, alongside a temporal relationship that suggests residents were infected by staff [ 35 ].…”

Nursing home staff networks and COVID-19

“…Further, ref. 21 also shows that whole-genome sequencing of positive samples from residents and staff indicated cross-infection between residents and staff as well as multiple introductions of the virus into individual care homes. In a different congregate setting, movement of staff and residents across three affiliated homeless shelters likely contributed to outbreaks in each location ( 22 ).…”

“…The CDC’s evaluation of the Kirkland, WA, outbreak pointed specifically to staff employed at multiple nursing homes as a factor in spreading the initial outbreak to additional homes ( 8 ). A study of four nursing homes in London ( 21 ) finds that 11% of staff worked in multiple homes, and these workers were 3 times as likely to be infected as workers in a single home. Further, ref.…”