A systematic review of evidence presented at the 2020 ESCMID Conference on Coronavirus Disease (ECCVID) showed that air around patients with COVID-19, as well as patient toilets, and staff and public areas in surveyed hospitals all showed significant levels of contamination with SARS-CoV-2.
Controversy remains worldwide regarding the transmission mode of SARS-CoV-2 virus in hospital settings. In this study, the authors reviewed the current evidence on air contamination with SARS-CoV-2 in hospital settings, viral load and particle size, and factors associated with contamination.
Dr Gabriel Birgand, University Hospital Centre Nantes, France, and colleagues, searched online databases for articles detailing SARS-CoV-2 air contamination in hospital settings between 1 December 2019 and 21 July 2020. The positivity rate of SARS-CoV-2 viral RNA and culture were described and compared according to the setting, clinical context, air ventilation system, and distance from patient.
A total of 17 articles, which included 646 air samples, were deemed eligible and included in the review.
Question: What are the clinical implications of this research?
"This review suggests very few infectivity of the air around covid-19 patients. We find RNA but not viable virus.
Birgand: "This is confirming that current personal protective equipment, including the use of surgical facemask is efficient in preventing patient to professional transmission in most cares, except aerosol generating procedures where FFP2 is required."
Overall, 27.5% (68/247) of air sampled from close patients' environment were positive for SARS-CoV-2 RNA, with no difference between settings (ICU: 27/97, 27.8%; non-ICU: 41/150, 27.3%).
Only 1/64 (1.5%) of samples in the air less than one metre from the patient tested positive for SARS-CoV-2, and 4/67 (6%) of samples one-to-five metres away.
In other areas, the positivity rate was 23.8% (5/21) in patient toilets, 9.5% (20/221) in clinical areas, 12.4% (15/121) in staff areas, and 34.1% (14/41) in public areas.
Of 78 viral cultures performed, three (4%) were positive, all from close patient environments (3/39, 7.7%) in non-ICU settings.
The median SARS-CoV-2 RNA concentrations were found to be 10 times higher in patient toilets than in the patients’ rooms.
The authors said “the high viral loads found in toilet/bathrooms, staff and public hallways means these areas require strong compliance with cleaning measures and personal protective equipment".