Clinical Infectious Diseases
IDSA GUIDELINES
Infectious Diseases Society of America Guidelines on
Infection Prevention for Healthcare Personnel Caring for
Patients With Suspected or Known COVID-19
(November 2021)
Downloaded from https://academic.oup.com/cid/article/78/7/e230/6428563 by University of Texas - Arlington user on 27 April 2025
John B. Lynch,1, Perica Davitkov,2 Deverick J. Anderson,3 Adarsh Bhimraj,4 Vincent Chi-Chung Cheng,5 Judith Guzman-Cottrill,6 Jasmine Dhindsa7,
Abhijit Duggal,8 Mamta K. Jain,9 Grace M. Lee,10 Stephen Y. Liang,11 Allison McGeer,12 Jamie Varghese,13 Valery Lavergne,14 M. Hassan Murad,15
Reem A. Mustafa,16 Shahnaz Sultan,17 Yngve Falck-Ytter,2 and Rebecca L. Morgan13
1
Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, USA; 2VA Northeast Ohio Healthcare System, Case Western Reserve University
School of Medicine, Cleveland, Ohio, USA; 3Duke Center for Antimicrobial Stewardship and Infection Prevention, Duke University School of Medicine, Durham, North Carolina, USA; 4Department of
Infectious Diseases, Cleveland Clinic, Cleveland, Ohio, USA; 5Queen Mary Hospital, Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special
Administrative Region, China; 6Department of Pediatrics, Division of Infectious Diseases, Oregon Health and Science University, Portland, Oregon, USA; 7Renown Health, University of Nevada, Reno,
Nevada, USA; 8Department of Critical Care, Cleveland Clinic, Cleveland, Ohio, USA; 9Department of Internal Medicine, Division of Infectious Diseases, UT Southwestern Medical Center, Dallas, Texas,
USA; 10Department of Pediatrics-Infectious Disease, Stanford University School of Medicine, Stanford, California, USA; 11Divisions of Infectious Diseases and Emergency Medicine, Washington
University School of Medicine, St. Louis, Missouri, USA; 12Department of Microbiology, Sinai Health System, University of Toronto, Toronto, Ontario, Canada; 13Department of Health Research
Methods, Evidence and Impact, McMaster University, Hamilton, Ontario, Canada; 14Department of Pathology and Laboratory Medicine, Vancouver General Hospital, Vancouver, British Columbia,
Canada; 15Division of Preventive Medicine, Mayo Clinic, Rochester, Minnesota, USA; 16Division of Nephrology and Hypertension, Department of Internal Medicine, University of Kansas Medical
Center, Kansas City, Kansas, USA; and 17Division of Gastroenterology, Hepatology, and Nutrition, University of Minnesota, Minneapolis VA Health Care System, Minneapolis, Minnesota, USA
Background. Since its emergence in late 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to
pose a risk to healthcare personnel (HCP) and patients in healthcare settings. Although all clinical interactions likely carry some risk
of transmission, human actions, such as coughing, and care activities, such as aerosol-generating procedures, likely have a higher
risk of transmission. The rapid emergence and global spread of SARS-CoV-2 continues to create significant challenges in healthcare
facilities, particularly with shortages of the personal protective equipment (PPE) used by HCP. Evidence-based recommendations
for what PPE to use in conventional, contingency, and crisis standards of care continue to be needed. Where evidence is lacking, the
development of specific research questions can help direct funders and investigators. The purpose of the current study was to develop
evidence-based rapid guidelines intended to support HCP in their decisions about infection prevention when caring for patients
with suspected or known coronavirus disease 2019 (COVID-19).
Methods. The Infectious Diseases Society of America (IDSA) formed a multidisciplinary guideline panel including frontline
clinicians, infectious disease specialists, experts in infection control, and guideline methodologists, with representation from the
disciplines of public health, medical microbiology, pediatrics, critical care medicine and gastroenterology. The process followed a
rapid recommendation checklist. The panel prioritized questions and outcomes. Then a systematic review of the peer-reviewed and
gray literature was conducted. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was
used to assess the certainty of evidence and make recommendations.
Results. The IDSA guideline panel agreed on 8 recommendations, including 2 updated recommendations and 1 new recommenda-
tion added since the first version of the guideline. Narrative summaries of other interventions undergoing evaluations are also included.
Conclusions. Using a combination of direct and indirect evidence, the panel was able to provide recommendations for 8 spe-
cific questions on the use of PPE by HCP providing care for patients with suspected or known COVID-19. Where evidence was
lacking, attempts were made to provide potential avenues for investigation. There remain significant gaps in the understanding of
the transmission dynamics of SARS-CoV-2, and PPE recommendations may need to be modified in response to new evidence. These
recommendations should serve as a minimum for PPE use in healthcare facilities and do not preclude decisions based on local risk
assessments or requirements of local health jurisdictions or other regulatory bodies.
Keywords. infection prevention; infection control; occupational health; employee health; personal protective equipment; PPE;
COVID-19; SARS-CoV-2.
Received 9 November 2021; editorial decision 9 November 2021; published online 15 It is important to realize that guidelines cannot always ac-
November 2021.
Correspondence: J. B. Lynch, Department of Medicine, Division of Allergy and Infectious
count for individual variation among patients. They are assess-
Diseases, University of Washington, Harborview Medical Center, 325 9th Ave, Box 359778, ments of current scientific and clinical information provided
Seattle, WA 98104 ().
as an educational service, are not continually updated and
Clinical Infectious Diseases® 2024;78(7):e230–e249
© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society
may not reflect the most recent evidence (new evidence may
of America. All rights reserved. For permissions, e-mail: . emerge between the time information is developed and when
https://doi.org/10.1093/cid/ciab953
e230 • CID 2024:78 (15 June) • Lynch et al
,it is published or read), should not be considered inclusive of
all proper treatment methods of care or as a statement of the
standard of care, do not mandate any particular course of med-
ical care, and are not intended to supplant physician judgment
with respect to particular patients or special clinical situations.
Whether and to what extent to follow guidelines is voluntary,
with the ultimate determination regarding their application
to be made by the physician in the light of each patient’s indi-
vidual circumstances. While the Infectious Diseases Society of
America (IDSA) makes every effort to present accurate, com-
Downloaded from https://academic.oup.com/cid/article/78/7/e230/6428563 by University of Texas - Arlington user on 27 April 2025
plete, and reliable information, these guidelines are presented Figure 1. Infectious Diseases Society of America algorithm for appropriate per-
“as is” without any warranty, either express or implied. IDSA sonal protective equipment (PPE) in conventional and contingency or crisis settings.
Abbreviations: AGP, aerosol-generating procedure; COVID-19, coronavirus disease
(and its officers, directors, members, employees, and agents)
2019; PAPR, powered air-purifying respirator.
assume no responsibility for any loss, damage, or claim with
respect to any liabilities, including direct, special, indirect, or
consequential damages, incurred in connection with these with concerns for negatively affecting resources, the expert panel
guidelines or reliance on the information presented. acknowledged the knowledge gap and made no recommendation,
The guidelines represent the proprietary and copyrighted pro- highlighting the need for more definitive evidence.
perty of the IDSA (copyright 2021; all rights reserved). No part The IDSA guideline panel used the crisis standards of care
of these guidelines may be reproduced, distributed, or trans- framework to develop its recommendations [2–4]. In the set-
mitted in any form or by any means, including photocopying, ting of a pandemic with documented shortages of PPE across
recording, or other electronic or mechanical methods, without various healthcare settings, the availability of supplies is an im-
the prior written permission of IDSA. Permission is granted to portant driver of recommendations. Using the crisis capacity
physicians and healthcare providers solely to copy and use the framework, separate recommendations were made for contin-
guidelines in their professional practices and clinical decision gency or crisis capacity settings, acknowledging the limited
making. No license or permission is granted to any person or availability of PPE (Figure 1).
entity, and prior written authorization by IDSA is required, to For all recommendations below, the panel emphasizes the
sell, distribute, or modify the guidelines, or to make derivative impact of conventional, contingency, and crisis standards of
works of or incorporate the guidelines into any product, in- care on how PPE is used. It also is critical to emphasize the im-
cluding but not limited to clinical decision support software or portance of “appropriate PPE” in the care of patients with sus-
any other software product. Except for the permission granted pected or known COVID-19, including gowns and gloves, as
above, any person or entity desiring to use the guidelines in any well as adherence to standards for donning and doffing to mini-
way must contact IDSA for approval in accordance with the mize transmission. The panel recognizes the need to address the
terms and conditions of third-party use, in particular any use of potential role of eye protection and masks as part of standard
the guidelines in any software product. precautions, how to mitigate gown shortages (eg, use of garbage
bags as a safe alternative), and whether there is a role for hair
covers to prevent transmission of severe acute respiratory syn-
EXECUTIVE SUMMARY drome (SARS) coronavirus 2 (SARS-CoV-2). In addition, the
Summarized below are the recommendations for infection preven- behaviors, protocols, and environments associated with PPE
tion among healthcare personnel (HCP) caring for suspected or use—particularly while PPE is being removed—cannot be sep-
known patients with coronavirus disease 2019 (COVID-19). The arated from the technical qualities of the equipment. The panel
full text is available online (https://www.idsociety.org/practice- hopes to address these questions in subsequent updates.
guideline/covid-19-guideline-infection-prevention/) and includes
detailed descriptions of the background, methods, evidence sum- Routine Patient Care
mary, and rationale that support each recommendation, along with Conventional Settings
research needs [1] . In brief, per Grading of Recommendations Recommendation 1.—The IDSA guideline panel recommends that
Assessment, Development and Evaluation (GRADE) methods, re- HCP caring for patients with suspected or known COVID-19 use ei-
commendations are labeled as “strong” or “conditional.” The word ther a medical/surgical mask or N95 (or N99 or powered air-purifying
“recommend” indicates strong recommendations, and “suggest” respirator [PAPR]) respirator compared with no mask as part of ap-
indicates conditional recommendations. In situations where the propriate PPE. (strong recommendation; moderate certainty of evi-
guideline panel judged there was insufficient evidence of benefit dence). (Here and below, appropriate PPE includes—in addition to a
to support the use of specific personal protective equipment (PPE) mask or respirator—eye protection, gown, and gloves.)
IDSA Guidelines on Infection Prevention for HCP • CID 2024:78 (15 June) • e231
, Recommendation 2.—The IDSA guideline panel suggests that PPE (conditional recommendation; very low certainty evi-
HCP caring for patients with suspected or known COVID- dence). Remark: This recommendation assumes performance
19 use eye protection rather than no eye protection as part of of correct doffing sequence and hand hygiene are performed
appropriate PPE (conditional recommendation; very low cer- before and after removing the face shield or medical/surgical
tainty of evidence). mask covering the respirator.
Conventional, Contingency, or Crisis Capacity Settings
BACKGROUND
Recommendation 3.—The IDSA guideline panel makes no recom-
mendation for the use of double versus single glove pairs for The first cases of COVID-19 were reported from Wuhan,
healthcare PPE (knowledge gap) China in early December 2019 [5], and the disease is now
Downloaded from https://academic.oup.com/cid/article/78/7/e230/6428563 by University of Texas - Arlington user on 27 April 2025
known to be caused by a novel beta-coronavirus, SARS-
Recommendation 4.—The IDSA guideline panel makes no recom- CoV-2. Within a span of months, COVID-19 became a
mendation for the use of shoe covers versus no shoe covers for pandemic owing to its transmissibility, spreading across con-
HCP caring for patients with suspected or known COVID-19 as tinents with the numbers of cases and deaths rising daily
part of appropriate PPE (knowledge gap). [6]. Although many infected individuals are asymptomatic
or exhibit a mild illness, 20% have severe or critical illness
Aerosol-Generating Procedures requiring hospitalization, and between 3% and 20% of hos-
Conventional Settings pitalized people die, depending on severity of illness [7–9].
Recommendation 5.—The IDSA guideline panel recommends The mortality rate remains even higher for patients requiring
that HCP involved with aerosol-generating procedures extracorporeal life support [5, 10–12]. Severity of illness is
(AGPs) in patients with suspected or known COVID-19 use associated with systematic barriers to care (racial constructs
an N95 (or N99 or PAPR) respirator instead of a medical/ and ethnicity), age, comorbid medical conditions, and preg-
surgical mask, as part of appropriate PPE (strong recommen- nancy [13, 14].
dation; very low certainty of evidence). Remark: Despite the Transmission occurs from persons incubating the disease be-
very low quality and indirect evidence supporting this rec- fore the onset of symptoms, from those with mild illness, and
ommendation, the IDSA guideline panel placed a high value from those with asymptomatic infection [15, 16]. Although viral
on avoiding serious harms to exposed HCP. shedding decreases soon after symptom onset, many patients
shed noninfectious viral RNA for prolonged periods [17–19].
Conventional, Contingency, or Crisis Capacity Settings
Throughout the course of infection, much remains unknown
Recommendation 6.—During contingency or crisis capacity set-
about the risk of transmission between patients and caregivers.
tings (N95 respirator shortages), the IDSA guideline panel sug-
The emergence of SARS-CoV-2 variants of concern, most no-
gests that HCP involved with AGPs in patients with suspected
tably the delta variant, and higher levels of transmission, create
or known COVID-19 use a reprocessed N95 respirator for reuse
additional complexity as findings of prior studies may not be
instead of medical/surgical masks as part of appropriate PPE
extrapolated to current or future conditions.
(conditional recommendation; very low certainty evidence).
Accurately identifying the contribution to overall transmis-
sion of different modes of transmission of respiratory viruses
Recommendation 7.—During contingency or crisis settings (res- has been a challenge. Over the last year, individuals and groups
pirator shortages), the IDSA guideline panel recommends that from different areas of science, most notably environmental
HCP involved with AGPs in patients with suspected or known aerosol researchers, have determined that the short-range con-
COVID-19 add a face shield or medical/surgical mask as a tinuum of small respiratory particles, ranging from aerosols to
cover for the N95 respirator to allow for extended use as part of droplets, is likely to represent the major contributors of trans-
appropriate PPE (strong recommendation; very low certainty mission [20, 21]. These findings call into question the historical
evidence). Remark: This recommendation assumes correct classification of precautions and associated PPE, most notably
doffing sequence and hand hygiene are performed before and droplet (requiring medical/surgical masks) and airborne (re-
after removing the face shield or medical/surgical mask cov- quiring respirators) precautions. Globally, many hospitals,
ering the respirator. clinics, and healthcare systems—if not most—have been using
droplet and contact precautions for patients with COVID-19
Recommendation 8.—During contingency or crisis settings (res- not undergoing AGPs throughout the pandemic.
pirator shortages), the IDSA guideline panel suggests that The primary mechanism to reduce aerosol transmission is
HCP involved with AGPs in patients with suspected or known ventilation. Higher levels of air exchanges and filtration are
COVID-19 add a face shield or medical/surgical mask as a cover commonly required in US healthcare settings, especially hos-
for the N95 respirator to allow for reuse as part of appropriate pitals [22]. In addition, the decay in viral load after symptom
e232 • CID 2024:78 (15 June) • Lynch et al
IDSA GUIDELINES
Infectious Diseases Society of America Guidelines on
Infection Prevention for Healthcare Personnel Caring for
Patients With Suspected or Known COVID-19
(November 2021)
Downloaded from https://academic.oup.com/cid/article/78/7/e230/6428563 by University of Texas - Arlington user on 27 April 2025
John B. Lynch,1, Perica Davitkov,2 Deverick J. Anderson,3 Adarsh Bhimraj,4 Vincent Chi-Chung Cheng,5 Judith Guzman-Cottrill,6 Jasmine Dhindsa7,
Abhijit Duggal,8 Mamta K. Jain,9 Grace M. Lee,10 Stephen Y. Liang,11 Allison McGeer,12 Jamie Varghese,13 Valery Lavergne,14 M. Hassan Murad,15
Reem A. Mustafa,16 Shahnaz Sultan,17 Yngve Falck-Ytter,2 and Rebecca L. Morgan13
1
Department of Medicine, Division of Allergy and Infectious Diseases, University of Washington, Seattle, Washington, USA; 2VA Northeast Ohio Healthcare System, Case Western Reserve University
School of Medicine, Cleveland, Ohio, USA; 3Duke Center for Antimicrobial Stewardship and Infection Prevention, Duke University School of Medicine, Durham, North Carolina, USA; 4Department of
Infectious Diseases, Cleveland Clinic, Cleveland, Ohio, USA; 5Queen Mary Hospital, Department of Microbiology, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special
Administrative Region, China; 6Department of Pediatrics, Division of Infectious Diseases, Oregon Health and Science University, Portland, Oregon, USA; 7Renown Health, University of Nevada, Reno,
Nevada, USA; 8Department of Critical Care, Cleveland Clinic, Cleveland, Ohio, USA; 9Department of Internal Medicine, Division of Infectious Diseases, UT Southwestern Medical Center, Dallas, Texas,
USA; 10Department of Pediatrics-Infectious Disease, Stanford University School of Medicine, Stanford, California, USA; 11Divisions of Infectious Diseases and Emergency Medicine, Washington
University School of Medicine, St. Louis, Missouri, USA; 12Department of Microbiology, Sinai Health System, University of Toronto, Toronto, Ontario, Canada; 13Department of Health Research
Methods, Evidence and Impact, McMaster University, Hamilton, Ontario, Canada; 14Department of Pathology and Laboratory Medicine, Vancouver General Hospital, Vancouver, British Columbia,
Canada; 15Division of Preventive Medicine, Mayo Clinic, Rochester, Minnesota, USA; 16Division of Nephrology and Hypertension, Department of Internal Medicine, University of Kansas Medical
Center, Kansas City, Kansas, USA; and 17Division of Gastroenterology, Hepatology, and Nutrition, University of Minnesota, Minneapolis VA Health Care System, Minneapolis, Minnesota, USA
Background. Since its emergence in late 2019, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) continues to
pose a risk to healthcare personnel (HCP) and patients in healthcare settings. Although all clinical interactions likely carry some risk
of transmission, human actions, such as coughing, and care activities, such as aerosol-generating procedures, likely have a higher
risk of transmission. The rapid emergence and global spread of SARS-CoV-2 continues to create significant challenges in healthcare
facilities, particularly with shortages of the personal protective equipment (PPE) used by HCP. Evidence-based recommendations
for what PPE to use in conventional, contingency, and crisis standards of care continue to be needed. Where evidence is lacking, the
development of specific research questions can help direct funders and investigators. The purpose of the current study was to develop
evidence-based rapid guidelines intended to support HCP in their decisions about infection prevention when caring for patients
with suspected or known coronavirus disease 2019 (COVID-19).
Methods. The Infectious Diseases Society of America (IDSA) formed a multidisciplinary guideline panel including frontline
clinicians, infectious disease specialists, experts in infection control, and guideline methodologists, with representation from the
disciplines of public health, medical microbiology, pediatrics, critical care medicine and gastroenterology. The process followed a
rapid recommendation checklist. The panel prioritized questions and outcomes. Then a systematic review of the peer-reviewed and
gray literature was conducted. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was
used to assess the certainty of evidence and make recommendations.
Results. The IDSA guideline panel agreed on 8 recommendations, including 2 updated recommendations and 1 new recommenda-
tion added since the first version of the guideline. Narrative summaries of other interventions undergoing evaluations are also included.
Conclusions. Using a combination of direct and indirect evidence, the panel was able to provide recommendations for 8 spe-
cific questions on the use of PPE by HCP providing care for patients with suspected or known COVID-19. Where evidence was
lacking, attempts were made to provide potential avenues for investigation. There remain significant gaps in the understanding of
the transmission dynamics of SARS-CoV-2, and PPE recommendations may need to be modified in response to new evidence. These
recommendations should serve as a minimum for PPE use in healthcare facilities and do not preclude decisions based on local risk
assessments or requirements of local health jurisdictions or other regulatory bodies.
Keywords. infection prevention; infection control; occupational health; employee health; personal protective equipment; PPE;
COVID-19; SARS-CoV-2.
Received 9 November 2021; editorial decision 9 November 2021; published online 15 It is important to realize that guidelines cannot always ac-
November 2021.
Correspondence: J. B. Lynch, Department of Medicine, Division of Allergy and Infectious
count for individual variation among patients. They are assess-
Diseases, University of Washington, Harborview Medical Center, 325 9th Ave, Box 359778, ments of current scientific and clinical information provided
Seattle, WA 98104 ().
as an educational service, are not continually updated and
Clinical Infectious Diseases® 2024;78(7):e230–e249
© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society
may not reflect the most recent evidence (new evidence may
of America. All rights reserved. For permissions, e-mail: . emerge between the time information is developed and when
https://doi.org/10.1093/cid/ciab953
e230 • CID 2024:78 (15 June) • Lynch et al
,it is published or read), should not be considered inclusive of
all proper treatment methods of care or as a statement of the
standard of care, do not mandate any particular course of med-
ical care, and are not intended to supplant physician judgment
with respect to particular patients or special clinical situations.
Whether and to what extent to follow guidelines is voluntary,
with the ultimate determination regarding their application
to be made by the physician in the light of each patient’s indi-
vidual circumstances. While the Infectious Diseases Society of
America (IDSA) makes every effort to present accurate, com-
Downloaded from https://academic.oup.com/cid/article/78/7/e230/6428563 by University of Texas - Arlington user on 27 April 2025
plete, and reliable information, these guidelines are presented Figure 1. Infectious Diseases Society of America algorithm for appropriate per-
“as is” without any warranty, either express or implied. IDSA sonal protective equipment (PPE) in conventional and contingency or crisis settings.
Abbreviations: AGP, aerosol-generating procedure; COVID-19, coronavirus disease
(and its officers, directors, members, employees, and agents)
2019; PAPR, powered air-purifying respirator.
assume no responsibility for any loss, damage, or claim with
respect to any liabilities, including direct, special, indirect, or
consequential damages, incurred in connection with these with concerns for negatively affecting resources, the expert panel
guidelines or reliance on the information presented. acknowledged the knowledge gap and made no recommendation,
The guidelines represent the proprietary and copyrighted pro- highlighting the need for more definitive evidence.
perty of the IDSA (copyright 2021; all rights reserved). No part The IDSA guideline panel used the crisis standards of care
of these guidelines may be reproduced, distributed, or trans- framework to develop its recommendations [2–4]. In the set-
mitted in any form or by any means, including photocopying, ting of a pandemic with documented shortages of PPE across
recording, or other electronic or mechanical methods, without various healthcare settings, the availability of supplies is an im-
the prior written permission of IDSA. Permission is granted to portant driver of recommendations. Using the crisis capacity
physicians and healthcare providers solely to copy and use the framework, separate recommendations were made for contin-
guidelines in their professional practices and clinical decision gency or crisis capacity settings, acknowledging the limited
making. No license or permission is granted to any person or availability of PPE (Figure 1).
entity, and prior written authorization by IDSA is required, to For all recommendations below, the panel emphasizes the
sell, distribute, or modify the guidelines, or to make derivative impact of conventional, contingency, and crisis standards of
works of or incorporate the guidelines into any product, in- care on how PPE is used. It also is critical to emphasize the im-
cluding but not limited to clinical decision support software or portance of “appropriate PPE” in the care of patients with sus-
any other software product. Except for the permission granted pected or known COVID-19, including gowns and gloves, as
above, any person or entity desiring to use the guidelines in any well as adherence to standards for donning and doffing to mini-
way must contact IDSA for approval in accordance with the mize transmission. The panel recognizes the need to address the
terms and conditions of third-party use, in particular any use of potential role of eye protection and masks as part of standard
the guidelines in any software product. precautions, how to mitigate gown shortages (eg, use of garbage
bags as a safe alternative), and whether there is a role for hair
covers to prevent transmission of severe acute respiratory syn-
EXECUTIVE SUMMARY drome (SARS) coronavirus 2 (SARS-CoV-2). In addition, the
Summarized below are the recommendations for infection preven- behaviors, protocols, and environments associated with PPE
tion among healthcare personnel (HCP) caring for suspected or use—particularly while PPE is being removed—cannot be sep-
known patients with coronavirus disease 2019 (COVID-19). The arated from the technical qualities of the equipment. The panel
full text is available online (https://www.idsociety.org/practice- hopes to address these questions in subsequent updates.
guideline/covid-19-guideline-infection-prevention/) and includes
detailed descriptions of the background, methods, evidence sum- Routine Patient Care
mary, and rationale that support each recommendation, along with Conventional Settings
research needs [1] . In brief, per Grading of Recommendations Recommendation 1.—The IDSA guideline panel recommends that
Assessment, Development and Evaluation (GRADE) methods, re- HCP caring for patients with suspected or known COVID-19 use ei-
commendations are labeled as “strong” or “conditional.” The word ther a medical/surgical mask or N95 (or N99 or powered air-purifying
“recommend” indicates strong recommendations, and “suggest” respirator [PAPR]) respirator compared with no mask as part of ap-
indicates conditional recommendations. In situations where the propriate PPE. (strong recommendation; moderate certainty of evi-
guideline panel judged there was insufficient evidence of benefit dence). (Here and below, appropriate PPE includes—in addition to a
to support the use of specific personal protective equipment (PPE) mask or respirator—eye protection, gown, and gloves.)
IDSA Guidelines on Infection Prevention for HCP • CID 2024:78 (15 June) • e231
, Recommendation 2.—The IDSA guideline panel suggests that PPE (conditional recommendation; very low certainty evi-
HCP caring for patients with suspected or known COVID- dence). Remark: This recommendation assumes performance
19 use eye protection rather than no eye protection as part of of correct doffing sequence and hand hygiene are performed
appropriate PPE (conditional recommendation; very low cer- before and after removing the face shield or medical/surgical
tainty of evidence). mask covering the respirator.
Conventional, Contingency, or Crisis Capacity Settings
BACKGROUND
Recommendation 3.—The IDSA guideline panel makes no recom-
mendation for the use of double versus single glove pairs for The first cases of COVID-19 were reported from Wuhan,
healthcare PPE (knowledge gap) China in early December 2019 [5], and the disease is now
Downloaded from https://academic.oup.com/cid/article/78/7/e230/6428563 by University of Texas - Arlington user on 27 April 2025
known to be caused by a novel beta-coronavirus, SARS-
Recommendation 4.—The IDSA guideline panel makes no recom- CoV-2. Within a span of months, COVID-19 became a
mendation for the use of shoe covers versus no shoe covers for pandemic owing to its transmissibility, spreading across con-
HCP caring for patients with suspected or known COVID-19 as tinents with the numbers of cases and deaths rising daily
part of appropriate PPE (knowledge gap). [6]. Although many infected individuals are asymptomatic
or exhibit a mild illness, 20% have severe or critical illness
Aerosol-Generating Procedures requiring hospitalization, and between 3% and 20% of hos-
Conventional Settings pitalized people die, depending on severity of illness [7–9].
Recommendation 5.—The IDSA guideline panel recommends The mortality rate remains even higher for patients requiring
that HCP involved with aerosol-generating procedures extracorporeal life support [5, 10–12]. Severity of illness is
(AGPs) in patients with suspected or known COVID-19 use associated with systematic barriers to care (racial constructs
an N95 (or N99 or PAPR) respirator instead of a medical/ and ethnicity), age, comorbid medical conditions, and preg-
surgical mask, as part of appropriate PPE (strong recommen- nancy [13, 14].
dation; very low certainty of evidence). Remark: Despite the Transmission occurs from persons incubating the disease be-
very low quality and indirect evidence supporting this rec- fore the onset of symptoms, from those with mild illness, and
ommendation, the IDSA guideline panel placed a high value from those with asymptomatic infection [15, 16]. Although viral
on avoiding serious harms to exposed HCP. shedding decreases soon after symptom onset, many patients
shed noninfectious viral RNA for prolonged periods [17–19].
Conventional, Contingency, or Crisis Capacity Settings
Throughout the course of infection, much remains unknown
Recommendation 6.—During contingency or crisis capacity set-
about the risk of transmission between patients and caregivers.
tings (N95 respirator shortages), the IDSA guideline panel sug-
The emergence of SARS-CoV-2 variants of concern, most no-
gests that HCP involved with AGPs in patients with suspected
tably the delta variant, and higher levels of transmission, create
or known COVID-19 use a reprocessed N95 respirator for reuse
additional complexity as findings of prior studies may not be
instead of medical/surgical masks as part of appropriate PPE
extrapolated to current or future conditions.
(conditional recommendation; very low certainty evidence).
Accurately identifying the contribution to overall transmis-
sion of different modes of transmission of respiratory viruses
Recommendation 7.—During contingency or crisis settings (res- has been a challenge. Over the last year, individuals and groups
pirator shortages), the IDSA guideline panel recommends that from different areas of science, most notably environmental
HCP involved with AGPs in patients with suspected or known aerosol researchers, have determined that the short-range con-
COVID-19 add a face shield or medical/surgical mask as a tinuum of small respiratory particles, ranging from aerosols to
cover for the N95 respirator to allow for extended use as part of droplets, is likely to represent the major contributors of trans-
appropriate PPE (strong recommendation; very low certainty mission [20, 21]. These findings call into question the historical
evidence). Remark: This recommendation assumes correct classification of precautions and associated PPE, most notably
doffing sequence and hand hygiene are performed before and droplet (requiring medical/surgical masks) and airborne (re-
after removing the face shield or medical/surgical mask cov- quiring respirators) precautions. Globally, many hospitals,
ering the respirator. clinics, and healthcare systems—if not most—have been using
droplet and contact precautions for patients with COVID-19
Recommendation 8.—During contingency or crisis settings (res- not undergoing AGPs throughout the pandemic.
pirator shortages), the IDSA guideline panel suggests that The primary mechanism to reduce aerosol transmission is
HCP involved with AGPs in patients with suspected or known ventilation. Higher levels of air exchanges and filtration are
COVID-19 add a face shield or medical/surgical mask as a cover commonly required in US healthcare settings, especially hos-
for the N95 respirator to allow for reuse as part of appropriate pitals [22]. In addition, the decay in viral load after symptom
e232 • CID 2024:78 (15 June) • Lynch et al
