Environmental sampling for SARS-CoV-2 in long term care facilities: lessons from a pilot study

Rachel Kwiatkowska; Nicola Yaxley; Ginny Moore; Allan Bennett; Matthew Donati; Nicola Love; Roberto Vivancos; Matthew Hickman; Derren R Ready

doi:10.12688/wellcomeopenres.17047.2

Environmental sampling for SARS-CoV-2 in long term care facilities: lessons from a pilot study

Wellcome Open Res. 2023 Jun 28:6:235. doi: 10.12688/wellcomeopenres.17047.2. eCollection 2021.

Authors

Rachel Kwiatkowska^{1

2

3}, Nicola Yaxley⁴, Ginny Moore⁴, Allan Bennett⁴, Matthew Donati^{5

6}, Nicola Love⁷, Roberto Vivancos^{8

9}, Matthew Hickman^{1

2}, Derren R Ready^{2

3

10}

Affiliations

¹ Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, UK.
² NIHR Health Protection Research Unit in Behavioural Science and Evaluation, University of Bristol, Bristol, UK.
³ Field Service, Health Protection Operations, UKHSA, Bristol, UK.
⁴ Biosafety, Air and Water Microbiology Group, UKHSA, Porton Down, Salisbury, UK.
⁵ Severn Infection Sciences, North Bristol NHS Trust, Bristol, UK.
⁶ UKHSA Specialised Microbiology and Laboratories,, South West Regional Laboratory, Bristol, UK.
⁷ Field Service, Health Protection Operations, UKHSA, Newcastle, UK.
⁸ NIHR Health Protection Research Unit in Gastrointestinal Infections, University of Liverpool, Liverpool, UK.
⁹ Field Service, Health Protection Operations, UKHSA, Liverpool, UK.
¹⁰ Eastman Dental Institute, University College London, London, UK.

Abstract

Background: The SARS-CoV-2 pandemic has highlighted the risk of infection in long-term care facilities (LTCF) and the vulnerability of residents to severe outcomes. Environmental surveillance may help detect pathogens early and inform Infection Prevention and Control (IPC) measures in these settings. Methods: Upon notification of SARS-CoV-2 outbreaks, LTCF within a local authority in South West England were approached to take part in this pilot study. Investigators visited to swab common touch-points and elevated 'non-touch' surfaces (>1.5m above ground level) and samples were analysed for presence of SARS-CoV-2 genetic material (RNA). Data were collected regarding LTCF infrastructure, staff behaviours, clinical and epidemiological risk factors for infection (staff and residents), and IPC measures. Criteria for success were: recruitment of three LTCF; detection of SARS-COV-2 RNA; variation in proportion of SARS-CoV-2 positive surfaces by sampling zone; and collection of clinical and epidemiological data for context. Results: Three LTCFs were recruited, ranging in size and resident demographics. Outbreaks lasted 63, 50 and 30 days with resident attack rates of 53%, 40% and 8%, respectively. The proportion of sample sites on which SARS-CoV-2 was detected was highest in rooms occupied by infected residents and varied elsewhere in the LTCF, with low levels in a facility implementing enhanced IPC measures. The heterogeneity of settings and difficulty obtaining data made it unfeasible to assess association between environmental contamination and infection. A greater proportion of elevated surfaces tested positive for SARS-CoV-2 RNA than common touch-points. Conclusions: SARS-CoV-2 RNA can be detected in a variety of LTCF outbreak settings, both on common-touch items and in elevated sites out of reach. This suggests that further work is justified, to assess feasibility and utility of environmental sampling for infection surveillance in LTCF.

Keywords: infection control; infectious disease transmission; environmental exposure; fomites; disease outbreaks; long-term care; epidemiologic methods.

Grants and funding

RK is funded through the Wellcome GW4 Clinical Academic Training programme [203918]