Airborne Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Hospitals : Effects of Aerosol-Generating Procedures, HEPA-Filtration Units, Patient Viral Load, and Physical Distance
(2022) In Clinical infectious diseases : an official publication of the Infectious Diseases Society of America 75(1). p.89-96- Abstract
BACKGROUND: Transmission of coronavirus disease 2019 (COVID-19) can occur through inhalation of fine droplets or aerosols containing infectious virus. The objective of this study was to identify situations, patient characteristics, environmental parameters, and aerosol-generating procedures (AGPs) associated with airborne severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus.
METHODS: Air samples were collected near hospitalized COVID-19 patients and analyzed by RT-qPCR. Results were related to distance to the patient, most recent patient diagnostic PCR cycle threshold (Ct) value, room ventilation, and ongoing potential AGPs.
RESULTS: In total, 310 air samples were collected; of these, 26 (8%) were positive for... (More)
BACKGROUND: Transmission of coronavirus disease 2019 (COVID-19) can occur through inhalation of fine droplets or aerosols containing infectious virus. The objective of this study was to identify situations, patient characteristics, environmental parameters, and aerosol-generating procedures (AGPs) associated with airborne severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus.
METHODS: Air samples were collected near hospitalized COVID-19 patients and analyzed by RT-qPCR. Results were related to distance to the patient, most recent patient diagnostic PCR cycle threshold (Ct) value, room ventilation, and ongoing potential AGPs.
RESULTS: In total, 310 air samples were collected; of these, 26 (8%) were positive for SARS-CoV-2. Of the 231 samples from patient rooms, 22 (10%) were positive for SARS-CoV-2. Positive air samples were associated with a low patient Ct value (OR, 5.0 for Ct <25 vs >25; P = .01; 95% CI: 1.18-29.5) and a shorter physical distance to the patient (OR, 2.0 for every meter closer to the patient; P = .05; 95% CI: 1.0-3.8). A mobile HEPA-filtration unit in the room decreased the proportion of positive samples (OR, .3; P = .02; 95% CI: .12-.98). No association was observed between SARS-CoV-2-positive air samples and mechanical ventilation, high-flow nasal cannula, nebulizer treatment, or noninvasive ventilation. An association was found with positive expiratory pressure training (P < .01) and a trend towards an association for airway manipulation, including bronchoscopies and in- and extubations.
CONCLUSIONS: Our results show that major risk factors for airborne SARS-CoV-2 include short physical distance, high patient viral load, and poor room ventilation. AGPs, as traditionally defined, seem to be of secondary importance.
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- author
- Thuresson, Sara LU ; Fraenkel, Carl Johan LU ; Sasinovich, Sviataslau LU ; Soldemyr, Jonathan LU ; Widell, Anders LU ; Medstrand, Patrik LU ; Alsved, Malin LU and Löndahl, Jakob LU
- organization
-
- Ergonomics and Aerosol Technology
- LTH Profile Area: Nanoscience and Semiconductor Technology
- LTH Profile Area: Aerosols
- LTH Profile Area: Engineering Health
- NanoLund: Centre for Nanoscience
- Infection Medicine (BMC)
- Clinical Virology, Malmö (research group)
- CCM BMC
- Clinical Microbiology, Malmö (research group)
- EpiHealth: Epidemiology for Health
- publishing date
- 2022-08-24
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- COVID-19, Hospitals, Humans, Physical Distancing, Respiratory Aerosols and Droplets, SARS-CoV-2, Viral Load
- in
- Clinical infectious diseases : an official publication of the Infectious Diseases Society of America
- volume
- 75
- issue
- 1
- pages
- 89 - 96
- publisher
- Oxford University Press
- external identifiers
-
- pmid:35226740
- scopus:85144521125
- ISSN
- 1537-6591
- DOI
- 10.1093/cid/ciac161
- language
- English
- LU publication?
- yes
- id
- 7e08ccaa-aab7-4d27-915c-2e5f0c2af23b
- date added to LUP
- 2022-10-17 14:48:53
- date last changed
- 2024-04-18 15:49:00
@article{7e08ccaa-aab7-4d27-915c-2e5f0c2af23b, abstract = {{<p>BACKGROUND: Transmission of coronavirus disease 2019 (COVID-19) can occur through inhalation of fine droplets or aerosols containing infectious virus. The objective of this study was to identify situations, patient characteristics, environmental parameters, and aerosol-generating procedures (AGPs) associated with airborne severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus.</p><p>METHODS: Air samples were collected near hospitalized COVID-19 patients and analyzed by RT-qPCR. Results were related to distance to the patient, most recent patient diagnostic PCR cycle threshold (Ct) value, room ventilation, and ongoing potential AGPs.</p><p>RESULTS: In total, 310 air samples were collected; of these, 26 (8%) were positive for SARS-CoV-2. Of the 231 samples from patient rooms, 22 (10%) were positive for SARS-CoV-2. Positive air samples were associated with a low patient Ct value (OR, 5.0 for Ct <25 vs >25; P = .01; 95% CI: 1.18-29.5) and a shorter physical distance to the patient (OR, 2.0 for every meter closer to the patient; P = .05; 95% CI: 1.0-3.8). A mobile HEPA-filtration unit in the room decreased the proportion of positive samples (OR, .3; P = .02; 95% CI: .12-.98). No association was observed between SARS-CoV-2-positive air samples and mechanical ventilation, high-flow nasal cannula, nebulizer treatment, or noninvasive ventilation. An association was found with positive expiratory pressure training (P < .01) and a trend towards an association for airway manipulation, including bronchoscopies and in- and extubations.</p><p>CONCLUSIONS: Our results show that major risk factors for airborne SARS-CoV-2 include short physical distance, high patient viral load, and poor room ventilation. AGPs, as traditionally defined, seem to be of secondary importance.</p>}}, author = {{Thuresson, Sara and Fraenkel, Carl Johan and Sasinovich, Sviataslau and Soldemyr, Jonathan and Widell, Anders and Medstrand, Patrik and Alsved, Malin and Löndahl, Jakob}}, issn = {{1537-6591}}, keywords = {{COVID-19; Hospitals; Humans; Physical Distancing; Respiratory Aerosols and Droplets; SARS-CoV-2; Viral Load}}, language = {{eng}}, month = {{08}}, number = {{1}}, pages = {{89--96}}, publisher = {{Oxford University Press}}, series = {{Clinical infectious diseases : an official publication of the Infectious Diseases Society of America}}, title = {{Airborne Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in Hospitals : Effects of Aerosol-Generating Procedures, HEPA-Filtration Units, Patient Viral Load, and Physical Distance}}, url = {{http://dx.doi.org/10.1093/cid/ciac161}}, doi = {{10.1093/cid/ciac161}}, volume = {{75}}, year = {{2022}}, }