Built Environment Airborne Infection Control Strategies in Pandemic Alternative Care Sites

Abstract

Objectives, Purposes, or Aim:

To identify design strategies utilized in airborne infection isolation and biocontainment patient rooms that improve infection control potential in an alternative care environment.

Background:

As SARS-CoV-2 spreads and health care facilities near or exceed capacity, facilities may implement alternative care sites (ACSs). With COVID-19 surges predicted, developing additional capacity in alternative facilities, including hotels and convention centers, into patient care environments requires early careful consideration of the existing space constraints, infrastructure, and modifications needed for patient care and infection control. Design-based strategies utilizing engineering solutions have the greatest impact, followed by medical and operational strategies.

Methods:

This article evaluates infection control and environmental strategies in inpatient units and proposes system modifications to ACS surge facilities to reduce infection risk and improve care environments.

Results:

Although adequate for an acute infectious disease outbreak, existing capacity in U.S. biocontainment units and airborne infection isolation rooms is not sufficient for widespread infection control and isolation during a pandemic. To improve patients’ outcomes and decrease infection transmission risk in the alternative care facility, hospital planners, administrators, and clinicians can take cues from evidence-based strategies implemented in biocontainment units and standard inpatient rooms.

Conclusions:

Innovative technologies, including optimized air-handling systems with ultraviolet and particle filters, can be an essential part of an infection control strategy. For flexible surge capacity in future ACS and hospital projects, interdisciplinary design and management teams should apply strategies optimizing the treatment of both infectious patients and minimizing the risk to health care workers.

Keywords

COVID-19 infection control evidence-based design pandemic isolation units field hospital research-informed design Sars-CoV-2 airflow environment of care

The novel coronavirus SARS-CoV-2, first identified in Wuhan, has spread globally to overwhelm health systems with limited intensive care unit beds (White & Lo, 2020; Zhu et al., 2020). With the potential for novel pathogens burdening health systems, planning must critically focus on infection control and prevention strategies. Although acuity-adaptable patient rooms have been a part of the hospital facility design zeitgeist, infection control–adaptable rooms and flexible care environments are imperative for a resilient pandemic response. Facing a patient surge, alternative care sites (ACSs), including convention centers, hotels, and military hospitals, provide additional patient capacity. However, these facilities still require infection control measures and careful planning best completed prior to a crisis. Potential larger, additional waves of COVID-19 cases add urgency to develop protocols to control viral spread and accommodate future patient surge and monitoring capacities (Kissler et al., 2020; Moore et al., 2020). With ACS frequently used in disaster response, but not necessarily a pandemic context, an effective strategy needs to be developed to mitigate infection transmission in ACS.

Historically, ACS infection control design has not addressed potentially infectious aerosol spread. Increasingly, evidence points to aerosolized SARS-CoV-2 transmission, presenting a new challenge for ACS precautions and source control. COVID-19-positive patients may release sufficient quantities of virus to cause infection (Ma et al., 2020; Watanabe et al., 2010). With further research, the scientific understanding of SARS-CoV-2 transmission routes will continue to be refined. Regardless, gas cloud dynamics for respiratory transmission need to be considered throughout ACS design and facility selection for resilience. ACS and other facilities need design-driven solutions to improve resilience to airborne pathogen spread.

The Centers for Disease Control and Prevention and National Institute for Occupational Safety and Health (NIOSH, 2015) Hierarchy of Controls stratifies approaches to improve infection prevention and health care delivery through design (Figure 1). Striving to eliminate or reduce hazards through facility design serves as a first line of defense and augments tailored workflows. For example, engineering strategies as simple as increasing the number of air changes per hour in an enclosed space can decrease effective viral loads (Beggs et al., 2008). These layers of redundancy, starting with the facility design itself, become critical for infection control, prevention, and protection.

Figure 1.

The Hierarchy of Controls framework stratifies the effectiveness of different methods of infection control and prevention. Source: Adapted from Centers for Disease Control and Prevention and National Institute for Occupational Safety and Health (2015).

Through administrative controls during the COVID-19 pandemic, facilities introduced operational changes, including patients and providers wearing masks, viral testing, and placing infected patients in isolation. While many of the protocol-driven controls developed for the COVID-19 pandemic may present future utility, it is important to consider how facility-based elimination, isolation, and engineering strategies can be incorporated into the ACS response playbook. Beyond SARS-CoV-2 outbreaks, facilities should be prepared to quickly and effectively adapt to emerging and novel infectious pathogens and appropriately modify infection control practices to account for transmission routes.

Learning From Infection Control Features in Airborne Infection Isolation Rooms

The Facility Guidelines Institute (FGI, 2018) Guidelines for the Design and Construction of Hospitals require facilities to have an adequate number of airborne infection isolation rooms based on infection control risk assessments. Best practices for negative-pressure patient room design and implementation enable airborne pathogens to be isolated through adequate recovery time in the anteroom and airflow directions that overcome air exchange (International Organization for Standardization, 2019; Sperna Weiland et al., 2020). By not recirculating unfiltered air outside the patient room, the risk of infecting others decreases. Specific requirements for SARS-CoV-2 viral loads, potentially stricter than the airborne guidelines developed for M. tuberculosis, should be considered as further research clarifies the SARS-CoV-2 concentrations, durations, and routes leading to infection.

In practice, however, only a limited quantity of patient rooms within the hospital are planned and built as negative-pressure airborne infection isolation rooms (American Hospital Association, 2020; Halpern, 2014). For a sufficient quantity of infection control care spaces, hospitals may need to adapt infection control features to existing patient rooms, dedicate units to infectious patients to increase resiliency, or turn to a purpose-built ACS.

Some medical centers have taken the airborne infection isolation concept further by developing independent biocontainment units equipped to handle highly infectious emerging pathogens and contain infection transmission (Courage, 2014; Garibaldi et al., 2016). Adapting evidence-based strategies developed for infection control into existing inpatient rooms and surge capacity designs may provide a more effective and flexible environment for infection control and health care worker safety.

While these biocontainment facilities offer the highest degree of infection control, they are in insufficient supply to be rapidly scaled for pandemics (Table 1). In pandemics, patient surges may overwhelm the health care system’s airborne infection isolation room capacity. It is neither realistic nor economical for each hospital to have adequate supply of biocontainment rooms or airborne infection isolation rooms to fully house infected patients in pandemics.

Table 1.

Supply of Inpatient Beds and Specialized Inpatient Beds in the United States.

Patient Bed Type	U.S. Quantity	United States per 100K	Reference
Staffed beds	534,964	163	American Hospital Association (2020)
Intensive care beds	96,596	29.4	American Hospital Association (2020)
Airborne infection isolation–capable beds (some airborne infection isolation beds are intensive care capable)	42,562	12.9	Halpern (2014)
Biocontainment-designed beds start (existing biocontainment unit beds are intensive care capable) Nebraska Medical Center (ten beds) Texas Children’s Hospital (eight beds) NIH Clinical Center (seven beds) Saint Patrick Hospital (three with six surge beds) Johns Hopkins Hospital (three beds) Emory University Hospital (two beds)	36	0.010

Learning From Infection Control Features in Biocontainment Facilities

Existing biocontainment patient rooms are acuity adaptable for intensive care, but insufficient in number. Lessons learned from these facilities beyond the FGI Guidelines airborne infection isolation code minimums can be incorporated into ACS design and workflows to help combat the spread of disease. These evidence-based strategies developed for infection control can create ACS that are safer for health care workers and more supportive for patient recovery. Effective personal protective equipment and protocols may provide acceptable infection control at reduced costs compared to biocontainment rooms, but without the resilience of engineering and design controls within the hierarchy of controls.

Biocontainment facilities are designed based on the concept of one-way airflow and segregated clean and soiled environments to strengthen infection control processes. As shown in Figure 2, maintaining spatial relationships with air flowing into the patient room and vented to the exterior results in safer conditions for providers and better infection containment. This design sequence, correlated with the clinical workflows of donning, doffing, and disposing protective gear, establishes a “hot zone” within the patient room, “warm zone” within the biocontainment unit, and one-way clean and soiled flow separation (Arrington, 2018).

Figure 2.

Biocontainment Unit Schematic Planning: Procession of flows in typical biocontainment patient isolation room pairs. Source: Adapted from the schematic layout of Texas Children’s Hospital biocontainment rooms.

Within the Johns Hopkins Biocontainment unit, laminar air diffusers are located above the patient bed, and the exhaust is located immediately behind the patient’s head. The unit air filtration captures 99% of 1.0-µm particles, exceeding airborne infection isolation code requirements (Garibaldi et al., 2016). Exhaust travels through high-efficiency particulate arrestance (HEPA) filters to the outside, capturing 99.99% of 0.3-µm particles.

Airflow Strategies and Infectious Diseases

Optimal airflows can mitigate infection risks within the built environment. Controlling airflow presents an opportunity to decrease airborne infection exposure including limiting potential viral particles traveling between hosts (American Society of Heating Refrigerating and Air-Conditioning Engineers [ASHRAE], 2020a). Personal protective equipment, including face masks, decreases exposure risk but does not eliminate the possibility of transmission entirely. The greatest results occur through elimination, isolation, and engineering controls (Centers for Disease Control and Prevention & National NIOSH, 2015).

Although aerosol pathogen concentration decreases as a function of the distance from the source, air clouds with potentially infectious droplets should be considered in ACS design. When researchers analyzed a cluster of cases in a poorly ventilated air-conditioned restaurant in Guangzhou, China, those positive for SARS-CoV-2 sat within the predominant airflow alongside the asymptomatic index-case patient (Lu et al., 2020). Those outside the predominant airflow were swab-negative for SARS-CoV-2. The researchers suggested the air conditioner’s airflow direction played a role transmitting infectious droplets or aerosol cloud. Further research applying a Wells–Riley model to an indoor choir practice where 53 of 61 individuals attending were infected showed consistencies between the model and potential COVID-19 airborne transmission (Miller et al., 2020).

ACSs

The U.S. Army Corps of Engineers (2020) sorts ACS into two categories: facilities with many small rooms and facilities with large open spaces suitable for 100 square foot patient pod deployments. Field hospital template designs promote rapid deployment (Figure 3A). Responding to patient surges, the ACS allows clinical care to proceed in controlled environments when beds in traditional facilities are fully occupied.

Responding to patient surges, the ACS allows clinical care to proceed in controlled environments when beds in traditional facilities are fully occupied.

Figure 3.

Models of Alternative Care Site Modules. Panel A: Typical 100 sf patient care module. Panel B: Airflow modifications to typical 100 sf module for the enclosed module with the exhaust on the patient headwall.

During Covid-19, ACS were initially considered for low-acuity noninfectious patients or mildly symptomatic infectious patients to reduce surge impact to hospitals and retain hospital capacity for more acute patients. With limited patient isolation capacity, military hospital ships, including the USNS Comfort and Mercy, were initially intended for noninfected patients (Ziezulewicz, 2020). The ships were designed for trauma care, not infection isolation. When hospitals in New York neared capacity, the Comfort prepared to treat SARS-CoV-2 patients while operating at 50% patient capacity, an administrative control. While a retrospective review will be informative to analyze ACS infection control effectiveness, generalizability may be limited by a reduced patient census on the Comfort and at other ACS facilities.

Field hospital deployment is reliant on and limited by the existing facility’s infrastructure. In addition to clarifying patient care requirements, ACS assessments should analyze existing fire safety, water, ventilation, sewage, utility, and communication systems. Converting interior spaces to ACS may require modifications to meet the anticipated clinical resilience. For individual rooms in a dormitory to convert to ACS, central ductwork may limit isolation potential. In large interior spaces within convention centers, airflow infrastructure may not support increasing air exchange to ventilate patient areas to the exterior.

Adapting ACSs

As ACSs are being considered to meet pandemic surges, adopting airborne infection isolation strategies will expand resilience. These sites may utilize a standard module that can be upgraded, depending on patient infection status and potential patient volume surge (Figure 3B).

For acute care, facilities with many small rooms such as hotels and dormitories are difficult to convert due to shared ventilation systems, narrow corridors, and difficult sightlines for providers, plus the challenge of cleaning to return the site to its original use. In the event social distancing continues and shelters are required in response to a disaster (a hurricane, wildfire, and extended power outage), these facilities may be adapted to “noncongregating” shelters with infection control precautions (Federal Emergency Management Agency, 2020).

A modular airflow system for ACS could be stored ready for deployment as surge capacity demands. At facilities with large floor areas anticipated to handle potentially infectious patients, pods with three walls and a curtain are constructed to provide barriers between patients. Since the pod’s curtain does not form a seal and the ceiling is often exposed, air may circulate between patient rooms and the corridor. To better regulate airflow similar to the biocontainment and airborne infection isolation units, the framework for patient pods could include a modular ventilation system added to direct airflow out of the patient corridor and into a HEPA-filtered exhaust to the exterior. This isolates air to specific patients and controls predominant flow, even without creating a full pressurized seal.

To better regulate airflow similar to the biocontainment and airborne infection isolation units, the framework for patient pods could include a modular ventilation system added to direct airflow out of the patient corridor and into a HEPA-filtered exhaust to the exterior.

ASHRAE (2020b) and NIOSH have developed strategies to leverage existing technologies to improve patient airflow. A portable snorkel exhaust establishes an airflow gradient with HEPA filtration at the patient headwall to control potentially infectious exhaled patient air and should be clearly labeled. Control, capture, and removal of infectious particles at their source reduce potential pathogen spread. Ventilated headboard designs filter air directly from the patient, decreasing the infectious agent concentration where a provider conducts their assessment (Mead, 2020). To improve field hospital efficiency, multiple headwall exhausts may be connected via temporary ductwork to a single HEPA filter (Figure 4A). In a NIOSH design, exhaled exhaust travels from the patient headwall through a HEPA filter before being released (Figure 4B).

Control, capture, and removal of infectious particles at their source reduce potential pathogen spread.

Figure 4.

Headboard Ventilation Strategies within Alternative Care Site Module. Panel A: Ventilated headboard and hood frame as constructed for research. Panel B: Airflow modifications to the typical 100sf module for a ventilated headboard exhaust and filtration system.

For ACS where infection control becomes a major concern and supply networks are intact, field hospital units can use prefabricated modular components including doors and a roof to enable better flexibility to direct airflow and a patient care environment designed in consultation with the hierarchy of controls. Creating airflow zones within the patient space improves margins of safety and decreases disease transmission risk (Mead & Johnson, 2004). Viral transmission and airflow dynamics for field hospital pods remain a topic of further study.

Some existing HVAC systems utilize filters and ultraviolet (UV) radiation to trap and inactivate particles, reducing hazards to maintenance staff as the filter is changed. Continuous low-dose far-UV-C (207–222 nm) exposure has shown promise in reducing airborne and fomite coronavirus concentration (Buonanno et al., 2020; Kitagawa et al., 2020). In practice, UV-C 254nm units integrated into a building’s design improve resilience. A longitudinal study in an acute care hospital investigating shielded UV-C units installed in negatively pressured patient rooms found reduced airborne bacteria colonies and reduced health care–acquired infections (Ethington et al., 2018). With a privacy curtain instead of a door or wall between the room and the corridor, air circulation may transmit from the corridor to the patient. When possible, systems should strive to utilize fresh air instead of a recirculation and filtration approach. An inlet system, potentially integrated into a headwall or area surrounding a patient’s bed, could facilitate airflow direction and exhaled air removal. Templates from NIOSH provide flexible approaches to such a headwall within the constraints of the typical ACS module (Mead, 2020; NIOSH, 2020). Future refinements to deployable patient rooms should consider methods to provide clean air within the ACS care environment.

Discussion

Lessons learned from the COVID-19 ACS deployments will further improve designs and operations for future patient surges, infection control challenges, and resilience approaches to airborne pathogen transmissions. Responding to SARS-CoV-2, facilities deployed temporary retrofits to increase the resilience of their clinical care system. Infection control successes and failures at ACS should be considered in reference to evidence-based metrics for airborne infection isolation protocols and biocontainment units. Airflow simulation studies can verify the effectiveness of the retrofit, improve renovations of existing spaces, and establish infection control thresholds for future ACS and hospital designs. Hospital planning may include rooms that can modulate pressurization, airflow direction, recovery time, or air changes per hour to create an engineering control responsive to patients’ infection and exposure risk. Although this article specifically addresses ACS, these strategies may also apply to dedicated postacute COVID-19 recovery spaces, skilled nursing facilities, and other indoor environments to reduce the risk of infection transmission.

Hospital planning may include rooms that can modulate pressurization, airflow direction, recovery time, or air changes per hour to create an engineering control responsive to patients’ infection and exposure risk.

Knowledge gained from experiences handling COVID-19 patient surges will lead to changes in facilities design and construction that better reduce communicable infection risks while facilitating efficient and effective care. Capital projects must target prevention measures and ways to limit infection spread to safeguard staff, patients, and visitors (Gan et al., 2020).

Thoughtful infection control planning, controlled airflow, and filtration in ACS potentially lessen complications and comorbidities during hospitalization. Improved care decreases length of stay and system costs. Although new infections may increase with length of stay in a confined space, dedicated airflow headwalls for each patient in the open environment of the ACS potentially reduces the spread of the source patient’s infectious materials.

Beyond the SARS-CoV-2 patient surges, prioritizing facility engineering controls that adequately ventilate, filter, and treat air (humidity, UV-C) in patient care areas may decrease infection spread. Facilities may consider strategies to increase air changes per hour or further control relative humidity to create infection control–adaptable rooms with cleaner air. If adaptable equipment is installed when existing equipment is replaced, the facility can increase infection resilience, while only incurring the differential expenses. Further validation will be needed to characterize airflow within the spaces and identify opportunities and potential differences between ventilation systems. At the same time, other measures beyond engineering controls in the hierarchy of controls should also be considered to increase the facility’s infection control and risk reduction. Given the often-rapid need for an ACS, planners should consider construction costs, supply chain feasibility, and anticipated use time lines in the ACS assessment.

Conclusions

The design of the built environment is a major determinant of the success of global public health efforts and the health care system’s resilience. The greatest return on investment in the hierarchy of controls are elimination, isolation, and engineering strategies. Validating innovative technologies that are affordable, safe, and clinically feasible within the ACS will allow for greater infection control resilience. Innovative systems, including air-handling systems with HEPA, UV-C, and particle filters integrated into ACS patient headwall modules can be an essential part of that optimization strategy. For flexible surge capacity in future ACS and hospital projects, interdisciplinary design and facility management teams should apply strategies to optimize infectious and noninfectious patient treatment and minimize the risk of pathogen transmission by reducing the spread routes in each patient’s care space.

Implications for Practice

Planning for infection control is required within alternative care facility design and development.

Strategies implemented in airborne infection isolation and biocontainment patient care rooms can be translated to the alternative care facility design.

A carefully considered infection control design contributes to improved patient outcomes and treatments and a decreased risk to health care workers.

A robust infection control design within alternative care facilities may increase the health system’s resiliency to respond to a patient surge, especially during a pandemic.

Supplemental Material

Supplemental Material, sj-pdf-1-her-10.1177_1937586720979832 - Built Environment Airborne Infection Control Strategies in Pandemic Alternative Care Sites

Supplemental Material, sj-pdf-1-her-10.1177_1937586720979832 for Built Environment Airborne Infection Control Strategies in Pandemic Alternative Care Sites by David Gordon, Jane Ward, Christopher J. Yao and Joyce Lee in HERD: Health Environments Research & Design Journal

Footnotes

Declaration of Conflicting Interests

The authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The authors received no financial support for the research, authorship, and/or publication of this article.

ORCID iD

David Gordon, EDAC

References

American Hospital Association. (2020). Fast facts on US hospitals. AHA Hospital Statistics. https://www.aha.org/statistics/fast-facts-us-hospitals

American Society of Heating Refrigerating and Air-Conditioning Engineers. (2020a). ASHRAE position document on aerosols.

American Society of Heating Refrigerating and Air-Conditioning Engineers. (2020b). Healthcare. Technical Resources. https://www.ashrae.org/technical-resources/healthcare#2person

Arrington

A. S.

(2018). Biocontainment principles for pediatric patients. In Bioemergency planning (pp. 117–128). Springer International Publishing. https://doi.org/10.1007/978-3-319-77032-1_10

Beggs

C. B.

Kerr

K. G.

Noakes

C. J.

Hathway

E. A.

Sleigh

P. A.

(2008). The ventilation of multiple-bed hospital wards: Review and analysis. American Journal of Infection Control, 36(4), 250–259. https://doi.org/10.1016/j.ajic.2007.07.012

Buonanno

Welch

Shuryak

Brenner

D. J.

(2020). Far-UVC light (222 nm) efficiently and safely inactivates airborne human coronaviruses. Scientific Reports, 10(1), 10285. https://doi.org/10.1038/s41598-020-67211-2

Centers for Disease Control and Prevention, & National Institute for Occupational Safety and Health. (2015). Hierarchy of Controls.

Courage

K. H.

(2014). Inside the 4 U.S. biocontainment hospitals that are stopping Ebola. Scientific American. https://www.scientificamerican.com/article/inside-the-4-u-s-biocontainment-hospitals-that-are-stopping-ebola-video/

Ethington

Newsome

Waugh

Lee

L. D.

(2018). Cleaning the air with ultraviolet germicidal irradiation lessened contact infections in a long-term acute care hospital. American Journal of Infection Control, 46(5), 482–486. https://doi.org/10.1016/j.ajic.2017.11.008

10.

Facilities Guidelines Institute. (2018). FGI Guidelines for Design and Construction of Hospitals, 2018. The Facilities Guidelines Institute.

11.

Federal Emergency Management Agency. (2020). Coronavirus (COVID-19) pandemic: Non-congregate sheltering.

12.

Gan

W. H.

Lim

J. W.

Koh

(2020). Preventing intra-hospital infection and transmission of Coronavirus disease 2019 in health-care workers. Safety and Health at Work, 11(2), 241–243. https://doi.org/10.1016/j.shaw.2020.03.001

13.

Garibaldi

B. T.

Kelen

G. D.

Brower

R. G.

Bova

Ernst

Reimers

Langlotz

Gimburg

Iati

Smith

MacConnell

James

Lewin

J. J.

Trexler

Black

M. A.

Lynch

Clarke

Marzinke

M. A.

Sokoll

L. J.

… Maragakis

L. L.

(2016). The creation of a biocontainment unit at a Tertiary Care Hospital: The Johns Hopkins medicine experience. Annals of the American Thoracic Society, 13(5), 600–608. https://doi.org/10.1513/AnnalsATS.201509-587PS

14.

Halpern

N. A.

(2014). Innovative designs for the smart ICU Part 2: The ICU. Chest, 145(3), 646–658. https://doi.org/10.1378/chest.13-0004

15.

International Organization for Standardization. (2019). Cleanrooms and associated controlled environments (ISO-EN Standard No. 14644-3). https://www.iso.org/obp/ui/#iso:std:iso:14644:-3:ed-2:v2:en

16.

Kissler

S. M.

Tedijanto

Goldstein

Grad

Y. H.

Lipsitch

(2020). Projecting the transmission dynamics of SARS-CoV-2 through the postpandemic period. Science, 368(6493), 860–868. https://doi.org/10.1126/science.abb5793

17.

Kitagawa

Nomura

Nazmul

Omori

Shigemoto

Sakaguchi

Ohge

(2020). Effectiveness of 222-nm ultraviolet light on disinfecting SARS-CoV-2 surface contamination. American Journal of Infection Control. https://doi.org/10.1016/j.ajic.2020.08.022

18.

Lai

Zhou

Yang

(2020). COVID-19 outbreak associated with air conditioning in restaurant, Guangzhou, China, 2020. Emerging Infectious Diseases, 26(7). https://doi.org/10.3201/eid2607.200764

19.

Chen

Zhang

Wang

Sun

Zhang

Guo

Morawska

Grinshpun

S. A.

Biswas

Flagan

R. C.

Yao

(2020). COVID-19 patients in earlier stages exhaled millions of SARS-CoV-2 per hour. Clinical Infectious Diseases. https://doi.org/10.1093/cid/ciaa1283

20.

Mead

(2020). NIOSH ventilated headboard provides solution to patient isolation during an epidemic. https://blogs.cdc.gov/niosh-science-blog/2020/04/14/ventilated-headboard/

21.

Mead

Johnson

D. L.

(2004). An evaluation of portable high-efficiency particulate air filtration for expedient patient isolation in epidemic and emergency response. Annals of Emergency Medicine, 44(6), 635–645. https://doi.org/10.1016/j.annemergmed.2004.07.451

22.

Miller

S. L.

Nazaroff

W. W.

Jimenez

J. L.

Boerstra

Buonanno

Dancer

S. J.

Kurnitski

Marr

L. C.

Morawska

Noakes

(2020). Transmission of SARS-CoV-2 by inhalation of respiratory aerosol in the Skagit Valley Chorale superspreading event. Indoor Air. https://doi.org/10.1111/ina.12751

23.

Moore

K. A.

Lipsitch

Barry

J. M.

Osterholm

M. T.

(2020). The CIDRAP Viewpoint. Part 1: the future of the COVID-19 pandemic: lessons learned from pandemic influenza. University of Minnesota.

24.

National Institute for Occupational Safety and Health. (2020). Engineering controls to reduce airborne, droplet and contact exposures during epidemic/pandemic response: ventilated headboard. https://www.cdc.gov/niosh/topics/healthcare/engcontrolsolutions/ventilated-headboard.html

25.

Sperna Weiland

N. H.

Traversari

R. A. A. L.

Sinnige

J. S.

van Someren Gréve

Timmermans

Spijkerman

I. J. B.

Ganzevoort

Hollmann

M. W.

(2020). Influence of room ventilation settings on aerosol clearance and distribution. British Journal of Anaesthesia. https://doi.org/10.1016/j.bja.2020.10.018

26.

U.S. Army Corps of Engineers. (2020). Alternate care sites (ACS) implementation support materials. https://www.usace.army.mil/Portals/2/docs/Contracting/AlternateCareSites/OverviewandRecommendations-20200322.pdf

27.

Watanabe

Bartrand

T. A.

Weir

M. H.

Omura

Haas

C. N.

(2010). Development of a dose-response model for SARS Coronavirus. Risk Analysis, 30(7), 1129–1138. https://doi.org/10.1111/j.1539-6924.2010.01427.x

28.

White

D. B.

(2020). A framework for rationing ventilators and critical care beds during the COVID-19 pandemic. JAMA, 323(18), 1773–1774. https://doi.org/10.1001/jama.2020.5046

29.

Zhu

Zhang

Wang

Yang

Song

Zhao

Huang

Shi

Niu

Zhan

Wang

Gao

G. F.

Tan

(2020). A novel Coronavirus from patients with pneumonia in China, 2019. New England Journal of Medicine, 382(8), 727–733. https://doi.org/10.1056/NEJMoa2001017

30.

Ziezulewicz

(2020, April 8). “The U.S.N.S. Comfort Is Now Taking Covid-19 Patients. Here’s What to Expect.” The New York Times Magazine. https://nyti.ms/3c1I4yk

Supplementary Material

Please find the following supplemental material available below.

For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.

For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.

0.00 MB

0.21 MB