Infection prevention and control for COVID-19: Interim guidance for acute healthcare settings

This document was updated and reposted on June 16, 2021. Please refer back for future updates.

Table of contents

Changes in recent updates

The Public Health Agency of Canada (PHAC) develops evidence-informed infection prevention and control (IPC) guidance to complement provincial and territorial public health efforts in monitoring, preventing, and controlling healthcare-associated infections. Guidance will necessarily shift with the benefit of new scientific findings and their replication, as well as with thoughtful consideration of implications for practice in areas of uncertainty. National-level guidance should always be read in conjunction with relevant provincial, territorial and local policies and regulations.

January 8, 2021

PHAC is updating its interim guidance on infection prevention and control in acute healthcare settings to consider emerging data on the transmission of SARS-CoV-2, the virus that causes COVID-19. While aerosol transmission occurs in some circumstances (e.g., prolonged contact in closed indoor spaces with poor ventilation) there remains uncertainty around aerosol transmission of SARS-CoV-2 and its impact in healthcare settings.

PHAC will continue to consider new evidence as it becomes available. The following statements summarize the current knowledge used to inform updates to the guidance:

In this context, the following recommendations are being made in this guidance. Acute healthcare facilities are also encouraged to refer to their provincial, territorial and local policies and regulations, which may vary depending on local epidemiology.

Heating, ventilation and air conditioning systems should be properly installed and regularly inspected and maintained

Updates added May 21, 2021

PHAC is updating its interim guidance on infection prevention and control in acute healthcare settings to consider the rollout of COVID-19 vaccines and emerging data on SARS-CoV-2 variants of concern.

PHAC will continue to consider new evidence as it becomes available. The following statements summarize the current knowledge used to inform updates to the guidance:

In this context, the following updated recommendations have been made in this guidance. Acute healthcare facilities are also encouraged to refer to their provincial, territorial and local policies and regulations.

SARS-CoV-2 variants of concern:

References to reuse or extended use of PPE have been removed from the guidance, except for extended use in the context of masks worn as source control, and eye protection worn for the duration of shifts (i.e., not when used for encounters with patients on Additional Precautions). If extended use of any disposable single-use PPE is deemed necessary under other circumstances, this should be in accordance with IPC expert consultation or guidance. As noted in previous guidance, a foundational concept in IPC practice is that disposable medical masks should not be re-worn.


Individuals responsible for policy development, implementation and oversight of IPC measures in acute healthcare settings should be familiar with relevant background documents on Routine Practices and Additional Precautions and occupational health and safety (OHS) legislation. IPC policies and procedures and training for COVID-19 should be developed in conjunction with joint occupational health and safety committees (JOHSC).

This document builds on the foundational IPC guidance for acute healthcare settings and provides guidance specific to COVID-19 in acute healthcare settings. IPC guidance documents for other healthcare settings can be found at Coronavirus disease (COVID-19): Guidance documents.


In December 2019, a cluster of cases of pneumonia of unknown origin was reported from Wuhan, Hubei Province in China. These cases were due to infection with a novel coronavirus, now called SARS-CoV-2, that causes a disease now referred to as COVID-19. A pandemic was declared by the World Health Organization on March 11, 2020.

For current information on the pandemic, please refer to the Public Health Agency of Canada Coronavirus Disease (COVID-19): Outbreak Update and to local, provincial or territorial public health authorities.

The purpose of this document is to provide updated interim IPC guidance to healthcare organizations and HCWs to prevent the transmission of COVID-19 in acute healthcare settings.

This interim guidance is based upon Canadian guidance developed for previous coronavirus outbreaks, experience with COVID-19 in Canada and other countries, as well as interim guidance from other international bodies. It has been informed by technical advice provided by members of the National Advisory Committee on Infection Prevention and Control (NAC-IPC). This guidance is informed by currently available scientific evidence and expert opinion, and is subject to change as new information becomes available.

Infection prevention and control practices at a glance

Employers must ensure that:

All HCWs should ensure that:

Active screening and notification

Prompt identification of all individuals (including inpatients) with signs or symptoms of infection should occur via active screening.

All confirmed cases of COVID-19 are to be reported to the relevant jurisdictional public health authorities.

Organizational readiness

Acute healthcare settings can minimize the risk of exposure to, and transmission of, COVID-19 within their facilities by conducting an organizational risk assessment for COVID-19 and by utilizing engineering controls and administrative controls.

Each acute healthcare facility should be prepared to identify and manage patients who are considered exposed to, or suspected or confirmed to have COVID-19.

Regardless of the number of COVID-19 cases occurring in a local community or region, acute healthcare facilities should conduct an organizational risk assessment of readiness for the management of cases of COVID-19 based on:

Organizational controls

It is essential that acute healthcare settings have the following engineering and administrative controls in place.

Engineering controls

Facility design should include:

Administrative controls

Policies and procedures for the prevention and control of transmission of COVID-19 within the acute healthcare setting should be implemented, including those regarding:

Staff, patients, and visitors should be provided with printed, posted, or other forms of accessible information in multiple languages as required, about COVID-19, how SARS-CoV-2 causes infection, and how to protect themselves and others, including:

Triage, patient and healthcare worker access points

Separate triage and/or waiting areas for patients who are suspected or confirmed to have COVID-19 should be created.

Acute healthcare settings should minimize access points and ensure that physical barriers (e.g., partitions or clear transparent barriers that help to prevent spread from person to person but also allow for easy communication) are in place at triage and reception desks, screening desks and patient reception areas or desks, and in emergency departments and any areas where patients present directly for treatment or care (e.g., diagnostic imaging centres, ambulatory care, outpatient laboratory testing and clinics).

The number of access points for HCWs should be minimized and separated from access points used for patients or visitors and other individuals. Active screening of all HCWs for illness should occur prior to entry into healthcare facilities. This may be facilitated through use of web-based tools or applications, with proof of completion provided at entry.

Access points for patients, visitors or other individuals and those used for HCWs should be determined according to the organizational risk assessment.

To prevent transmission of COVID-19 at entry points, triage, and waiting areas in acute healthcare settings:

Healthcare worker safety and training

Healthcare facilities should evaluate the potential risks posed to HCWs, and ensure that controls are in place to mitigate and manage these risks.

Patient care and infection prevention and control measures

Routine practices

Routine Practices apply to all staff and patients, at all times, in all acute healthcare settings and include but are not limited to:

Point-of-care risk assessment

Prior to any patient interaction, all HCWs have a responsibility to assess the infectious risks posed to themselves, other HCWs, and other patients and visitors from a patient, situation or procedure.

A PCRA includes determining if there may be:

Patient factors may include:

The selection and use of PPE during patient interactions should always be determined by the PCRA.

For interactions with patients who are considered exposed to, or suspected or confirmed to have COVID-19, PPE consistent with a minimum of Droplet and Contact Precautions (e.g., gloves, a gown, a medical mask and eye protection) should be worn. An N95 or equivalent respirator should be worn in place of a mask when performing an AGMP or when frequent or unexpected exposure to AGMPs is anticipated (e.g., on dedicated COVID-19 units). Use of an N95 or equivalent respirator may be considered in other circumstances under which risk of exposure to aerosolized virus may occur.

Hand hygiene

Acute healthcare settings should ensure that a current hand hygiene program is in place and is regularly reviewed, with improvements made as necessary.

Facilities should make every effort to achieve 100 percent hand hygiene adherence, with HCW performance of hand hygiene at least before and after contact with a patient or the patient care environment, before performing clean or sterile procedures, after risk of body fluid exposure, after removing gloves, and when hands are visibly soiled.

Hand hygiene is required before, during and after PPE removal, and between patient encounters.

Hands may be cleaned using ABHR containing 60 to 90 percent alcohol, or plain liquid soap and water when hands are visibly soiled.

Personal protective equipment

PPE should always be used in conjunction with engineering and administrative controls.

All PPE (e.g., gloves, gowns, medical masks, N95 or equivalent respirators, eye protection) should be supplied in adequate amounts and sizes in all patient care areas, and stored so it is readily accessible at the point-of-care for all HCWs and permitted visitors.

Training should be provided, with posters clearly outlining steps for putting on and removing PPE posted inside and outside each room of a patient who is suspected or confirmed to have COVID-19 for visual cues.

All HCWs using PPE should:

Masking and eye protection for the full duration of shifts or visits

Given ongoing community spread of COVID-19 within Canada and evidence that transmission occurs from those who have few or no symptoms, masking for the full duration of shifts or visits for all acute healthcare setting staff and visitors is recommended. The rationale for full-shift or visit masking of all staff and visitors is to reduce the risk of transmitting COVID-19 from staff or visitors to others, at a time when no symptoms of illness are recognized, but the virus can be transmitted. Staff should support visitors to ensure appropriate use of medical masks.

Use of eye protection (e.g., a face shield) for the full duration of HCW shifts is also recommended in all acute healthcare settings, based on local epidemiology. This applies to all staff working within 2 metres of patients.

HCWs should refer to provincial and territorial guidance and facility policies on specific recommendations for use of medical masks, eye protection and other PPE, as well as PPE conservation strategies. When medical masks for HCWs and visitors (and eye protection for HCWs) are recommended for the full duration of shifts or visits, HCWs and visitors should:

When an N95 or equivalent respirator is deemed necessary based on the HCW's PCRA, they should follow facility procedures for taking off a medical mask and eye protection then put on the N95 or equivalent respirator and replace their eye protection, with meticulous hand hygiene performed at all steps.

Masks worn as source control, and eye protection worn for the duration of shifts (i.e., not when used for encounters with patients on Additional Precautions), may be worn for extended periods. Any extended use policies should be developed with IPC expert consultation or guidance. Masks or N95 or equivalent respirators and eye protection should be replaced when they become damaged, wet, damp, or soiled (from the wearer's breathing or external splash), or when they come in direct contact with a patient. Staff should be informed of how to access additional masks or N95 or equivalent respirators and eye protection when needed.

Additional precautions

A minimum of Droplet and Contact Precautions should be implemented for all patients who are considered exposed to, diagnosed with, or who are presenting with signs or symptoms of COVID-19.

Aerosol-generating medical procedures

Some medical procedures have been reported to increase the likelihood of generating infectious aerosols, and linked to transmission of other respiratory viruses. These are often referred to as aerosol-generating procedures (AGPs) or aerosol-generating medical procedures (AGMPs). There are many knowledge gaps as to which procedures pose the greatest risk of aerosol generation and of transmission of SARS-CoV-2. It is likely that the degree of risk may also vary depending on the patient, the operator, and the setting. Some examples of procedures that have been reported to pose increased risk of infectious aerosol generation and transmission of coronaviruses include:

Guidance for other procedures that require the use of an N95 or equivalent respirator should be followed. This guidance may vary among provinces and territories.

AGMPs are ideally performed in AIIRs if these are available. If it is anticipated that a patient may require an AGMP, the patient should at minimum be placed in a private room with the door closed.

AGMPs on a patient who is considered potentially infectious with SARS-CoV-2 should only be performed when all HCWs in the room are wearing a fit-tested, seal-checked N95 or equivalent respirator, gloves, a gown and eye protection.

In addition:

Inpatient management

Before each patient interaction, a PCRA should be performed to determine the appropriate practices and precautions for safe patient care.

Placement and accommodation

The following are important considerations for patient placement and accommodation:

Patient flow and activity

Patients who are suspected or confirmed to have COVID-19 should be restricted to their room until they have met criteria for discontinuation of Additional Precautions in accordance with facility IPC protocols and provincial or territorial public health guidance. Patient movement or transport should also be restricted to essential diagnostic tests and therapeutic treatments. Transfer within and between facilities while patients are suspected to be infectious should be avoided unless medically necessary.

If patients must leave their room for medically necessary care or treatment, they should:

Any surfaces that may have been touched by the patient while out of their room should be cleaned and disinfected.

A minimum of Droplet and Contact Precautions should be maintained by HCWs during patient transport, and communicated along with relevant clinical information to the transferring service and receiving unit ahead of transfer.

Discontinuing additional precautions

The duration and discontinuation of Additional Precautions for an individual patient or unit (where precautions may be universally applied during a COVID-19 outbreak) should be determined on a case-by-case basis, in consultation with the IPC program and in accordance with provincial or territorial public health guidance and organizational policies. The duration of Additional Precautions for a symptomatic patient with COVID-19 should be for a minimum of 10 days from onset of symptoms (and a minimum of 10 days from first positive testing for patients who remain asymptomatic), and may be longer dependent upon duration of symptoms, disease severity and the presence of any underlying immunocompromising conditions.

Handling bodies of deceased persons

Routine Practices should be used properly and consistently when handling the bodies of people who are deceased, including preparing bodies for autopsy or transfer to mortuary services. Federal guidance is available, and provincial and territorial communicable disease regulations should be followed.

Handling laboratory specimens

All specimens collected for laboratory investigations should be regarded as potentially infectious. Clinical specimens should be collected and transported in accordance with organizational policies and procedures. For proper laboratory biosafety procedures when handling samples from patients under investigation for COVID-19, refer to the PHAC's biosafety advisory.

Handling patient care equipment

All reusable equipment and supplies, along with toys, electronic games, personal belongings, etc., should be dedicated to the use of the patient who is suspected or confirmed to have COVID-19. If reuse with other patients is necessary, the equipment and supplies should first be cleaned, and disinfected with a hospital-grade disinfectant for the recommended contact time.

Upon patient transfer or discharge, items that cannot be appropriately cleaned and disinfected should be discarded. Patient-owned items should be taken home by the patient, and unwanted items discarded.

Single-use disposable equipment should be discarded into a no-touch waste receptacle after use.

Environmental cleaning and disinfection

Cleaning and disinfection of high-touch surfaces is important for controlling the spread of microorganisms. Environmental disinfectants should be classed as hospital disinfectants, registered in Canada with a Drug Identification Number (DIN), and labelled as effective for both enveloped and non-enveloped viruses. Manufacturer's instructions for use and required contact times should be followed to ensure adequate disinfection.

All patient room surfaces that are considered "high touch" (e.g., telephone, bedside table, overbed table, chair arms, call bell cords or buttons, door handles, light switches, bedrails, handwashing sink, bathroom sink, toilet and toilet handles, shower handles, faucets, shower chairs, grab bars, outside of paper towel dispenser) should be cleaned and disinfected at least daily and when soiled. Hospital-grade disinfectant (e.g., disinfectant wipes) should be used with the recommended contact time to disinfect smaller patient care equipment (e.g., blood pressure cuffs, electronic thermometers, pulse oximeters, stethoscopes) after each use. Room cleaning and disinfection of low-touch surfaces (e.g., shelves, bedside chairs or benches, windowsills, headwall units, overbed light fixtures, message or white boards, outside of sharps containers) should also be performed on a regular basis and when soiled. Floors and walls should be kept visibly clean and free of spills, dust and debris.

All surfaces or items outside of the patient room that are touched by or in contact with HCWs (e.g., computer carts, medication carts, charting desks or tables, computer screens, telephones, touch screens, chair arms) should be cleaned and disinfected at least daily and when soiled.

In hospital rooms or common areas where there are more likely to be patients with unknown, suspected or confirmed COVID-19 infection status, multiple or high turnover over of patients (e.g., emergency departments, ambulatory clinics) or staff (e.g., cafeterias), and in cases of outbreaks, more frequent cleaning and disinfection is required.

Environmental Services staff should wear the same PPE as other HCWs when cleaning and disinfecting the patient room.

The acute healthcare facility's cleaning and disinfection protocols for cleaning and disinfection of the patient room after discharge, transfer, or discontinuation of Droplet and Contact Precautions should be followed. Toilet brushes, unused toilet paper and other disposable supplies should be discarded, and all bedside privacy curtains removed and laundered at the time of patient discharge or transfer.

Linen, dishes and cutlery

No special precautions are recommended; Routine Practices are used.

Waste management

No special precautions are recommended; Routine Practices are used.

Management of healthcare worker exposures

The organization's OHS professional(s), and ICPs should work collaboratively with public health authorities to manage exposed HCWs.

Visitor management

Visitation policies and restrictions may vary across jurisdictions and facilities depending on the degree of local transmission of COVID-19. These should be developed and implemented to balance the risk of infectious disease transmission and the promotion of patient and family-centered care.

Monitoring and evaluation

Acute healthcare settings should ensure that processes are in place to monitor outcomes or occurrences related to managing patients with suspected or confirmed COVID-19. These may include:


Ahmad, J., Anwar, S., Latif, A., Haq, N. U., Sharif, M., & Nauman, A. A. (2020). The Association of PPE Availability, Training and Practices with COVID-19 Sero-prevalence in Nurses and Paramedics in Tertiary Care Hospitals of Peshawar, Pakistan. Disaster Med Public Health Prep, 1-18. doi:10.1017/dmp.2020.438

Airborne Transmission of SARS-CoV-2 - Proceedings of a Workshop. Retrieved from

Alajmi, J., Jeremijenko, A. M., Abraham, J. C., Alishaq, M., Concepcion, E. G., Butt, A. A., & Abou-Samra, A.-B. (2020). COVID-19 infection among healthcare workers in a national healthcare system: The Qatar experience. Int J of Infect Dis, 100, 386-389. doi:10.1016/j.ijid.2020.09.027

Alberta Health Services. (2020, June 12). Topic: Effectiveness of screening programs for reducing the spread of COVID-19 in healthcare settings. Retrieved from:

Alberta Health Services. (2020, June 5). Has there been documented transmission of SARS-Cov-2 virus (or similar viruses) through heating, ventilation, and air conditioning (HVAC) systems in hospitals or nonhospital settings? Retrieved from:

Alkurt, G., Murt, A., Aydin, Z., Tatli, O., Agaoglu, N. B., Irvem, A.,... Doganay, L. (2020). Seroprevalence of coronavirus disease 2019 (COVID-19) among health care workers from three pandemic hospitals of Turkey. Preprint medRxiv doi:10.1101/2020.08.19.20178095

Andreano, E., Piccini, G., Licastro, D., Casalino, L., Johnson, N. V., Paciello, I.,... Rappuoli, R. (2020). SARS-CoV-2 escape in vitro from a highly neutralizing COVID-19 convalescent plasma. Preprint bioRxiv. doi:10.1101/2020.12.28.424451

Amit, S., Regev-Yochay, G., Afek, A., Kreiss, Y., & Leshem, E. (2021). Early rate reductions of SARS-CoV 2 infection and COVID-19 in BNT162b2 vaccine recipients. Lancet, 397(10277), 875-877. doi:10.1016/S0140-6736(21)00448-7

Asadi, S., Wexler, A. S., Cappa, C. D., Barreda, S., Bouvier, N. M., & Ristenpart, W. D. (2019). Aerosol emission and superemission during human speech increase with voice loudness. Sci Rep, 9(1), 2348. doi:10.1038/s41598-019-38808-z

Bae, S., Kim, H., Jung, T. Y., Lim, J. A., Jo, D. H., Kang, G. S.,... Kwon, H. J. (2020). Epidemiological Characteristics of COVID-19 Outbreak at Fitness Centers in Cheonan, Korea. J Korean Med Sci, 35(31), e288. doi:10.3346/jkms.2020.35.e288

Baden, L. R., El Sahly, H. M., Essink, B., Kotloff, K., Frey, S., Novak, R.,... Group, C. S. (2021). Efficacy and Safety of the mRNA-1273 SARS-CoV-2 Vaccine. N Engl J Med, 384(5), 403-416. doi:10.1056/NEJMoa2035389

Bartoszko, J. J., Farooqi, M. A. M., Alhazzani, W., & Loeb, M. (2020). Medical masks vs N95 respirators for preventing COVID-19 in healthcare workers: A systematic review and meta-analysis of randomized trials. Influenza Other Respir Viruses, 14(4), 365-373. doi:10.1111/irv.12745

Bourouiba, L. (2020). Turbulent Gas Clouds and Respiratory Pathogen Emissions: Potential Implications for Reducing Transmission of COVID-19. JAMA, 323(18), 1837-1838. doi:10.1001/jama.2020.4756

Cai, J., Sun, W., Huang, J., Gamber, M., Wu, J., & He, G. (2020). Indirect Virus Transmission in Cluster of COVID-19 Cases, Wenzhou, China, 2020. Emerg Infect Dis, 26(6), 1343-1345. doi:10.3201/eid2606.200412

Calò, F., Russo, A., Camaioni, C., De Pascalis, S., & Coppola, N. (2020). Burden, risk assessment, surveillance and management of SARS-CoV-2 infection in health workers: A scoping review. Infect Dis Poverty, 9 (1), 139. doi:10.1186/s40249-020-00756-6

Cao, G., Tang, S., Yang, D., Shi, W., Wang, X., Wang, H.,... Ma, L. (2020). The potential transmission of SARS-CoV-2 from patients with negative RT-PCR swab tests to others: two related clusters of COVID-19 outbreak. Jpn J Infect Dis, 73(6), 399-403. doi:10.7883/yoken.JJID.2020.165

Carretta, G., Contessa, C., Boemo, D. G., Bordignon, G., Bennici, S. E., Merigliano, S.,... Donato, D. (2020). COVID-19 challenge: Proactive management of a tertiary university hospital in Veneto region, Italy. Pathog Glob Health, 114(6), 309-317. doi:10.1080/20477724.2020.1806614

Cattelan, A. M., Sasset, L., Di Meco, E., Cocchio, S., Barbaro, F., Cavinato, S.,..Baldo, V. (2020). An integrated strategy for the prevention of SARS-CoV-2 infection in healthcare workers: A prospective observational study. Int J Environ Res Public Health 17(16). doi:10.3390/ijerph17165785

Cele, S., Gazy, I., Jackson, L., Hwa, S. H., Tegally, H., Lustig, G.,... Sigal, A. (2021). Escape of SARS CoV-2 501Y.V2 from neutralization by convalescent plasma. Nature. doi:10.1038/s41586-021-03471-w

Centers for Disease Control and Prevention: Cluster of severe acute respiratory syndrome cases among protected health care workers - Toronto, April 2003. MMWR Morb Mortal Wkly Rep 2003; 52:433-436

Centers for Disease Control and Prevention. (2020). Interim Infection Prevention and Control Recommendations for Healthcare Personnel During the Coronavirus Disease 2019 (COVID-19) Pandemic. Retrieved from

Centers for Disease Control and Prevention. (2020). Discontinuation of Transmission-Based Precautions and Disposition of Patients with COVID-19 in Healthcare Settings (Interim Guidance). Retrieved from

Centers for Disease Control and Prevention. (2020). Duration of Isolation and Precautions for Adults with COVID-19. Retrieved from

Centers for Disease Control and Prevention. (2020). Scientific Brief: SARS-CoV-2 and Potential Airborne Transmission. Retrieved from

Chen, R. E., Zhang, X., Case, J. B., Winkler, E. S., Liu, Y., VanBlargan, L. A.,... Diamond, M. S. (2021). Resistance of SARS-CoV-2 variants to neutralization by monoclonal and serum-derived polyclonal antibodies. Nat Med. doi:10.1038/s41591-021-01294-w

Cheng, V. C., Wong, S. C., Chan, V. W., So, S. Y., Chen, J. H., Yip, C. C.,... Yuen, K. Y. (2020). Air and environmental sampling for SARS-CoV-2 around hospitalized patients with coronavirus disease 2019 (COVID-19). Infect Control Hosp Epidemiol, 41(11), 1258-1265. doi:10.1017/ice.2020.282

Chodick, G., Tene, L., Gazit, S., Ben Tov A., Cohen, D., & Muhsen, K. The effectiveness of the first dose of BNT162b2 vaccine in reducing SARS-CoV-2 infection 13-24 days after immunization: real-world evidence. Preprint medRxiv. doi:10.1101/2021.01.27.21250612

Chou, R., Dana, T., Buckley, D. I., Selph, S., Fu, R., & Totten, A. M. (2020). Update Alert 5: Epidemiology of and risk factors for coronavirus infection in health care workers: A living rapid review. Ann Intern Med, 173(2), 120-136. doi:10.7326/M20-1632 CIHR-PHAC-CADTH - Best Brains Exchange - Transmission Routes for COVID-19: Implications for Public Health. (2020). Retrieved from

Collier, D. A., De Marco, A., Ferreira, I., Meng, B., Datir, R., Walls, A. C.,... Gupta, R. K. (2021). SARS CoV-2 B.1.1.7 sensitivity to mRNA vaccine-elicited, convalescent and monoclonal antibodies. medRxiv. doi:10.1101/2021.01.19.21249840

Contejean, A., Leporrier, J., Canoui, E., Alby-Laurent, F., Lafont, E., Beaudeau, L., Kerneis, S. (2020). Comparing dynamics and determinants of SARS-CoV-2 transmissions among health care workers of adult and pediatric settings in central Paris. Clin Infect Dis. doi:10.1093/cid/ciaa977 Epub ahead of print.

Da Silva Francisco Jr., R., Benites, L. F., Lamarca, A. P., de Almeida, L. G. P., Hansen, A. W., Gularte, J. S.,... Spilki, F. R. (2021). Pervasive transmission of E484K and emergence of VUI-NP13L with evidence of SARS-CoV-2 co-infection events by two different lineages in Rio Grande do Sul, Brazil. Virus Res, 296, 198345. doi:10.1016/j.virusres.2021.198345

Dagan, N., Barda, N., Kepten, E., Miron, O., Perchik, S., Katz, M. A.,... Balicer, R. D. (2021). BNT162b2 mRNA Covid-19 Vaccine in a Nationwide Mass Vaccination Setting. N Engl J Med. doi:10.1056/NEJMoa2101765

Dan, J. M., Mateus, J., Kato, Y., Hastie, K. M., Yu, E. D., Faliti, C. E.,... Crotty, S. (2021). Immunological memory to SARS-CoV-2 assessed for up to 8 months after infection. Science, 371(6529). doi:10.1126/science.abf4063

Davies, N. G., Abbott, S., Barnard, R. C., Jarvis, C. I., Kucharski, A. J., Munday, J. D.,... Edmunds, W. J. (2021). Estimated transmissibility and impact of SARS-CoV-2 lineage B.1.1.7 in England. Science, 372(6538). doi:10.1126/science.abg3055

Davies, N. G., Jarvis, C. I., Group, C. C.-W., Edmunds, W. J., Jewell, N. P., Diaz-Ordaz, K., & Keogh, R. H. (2021). Increased mortality in community-tested cases of SARS-CoV-2 lineage B.1.1.7. Nature. doi:10.1038/s41586-021-03426-1

Diamond, M., Chen, R., Xie, X., Case, J., Zhang, X., VanBlargan, L.,... Gilchuk, P. (2021). SARS-CoV-2 variants show resistance to neutralization by many monoclonal and serum-derived polyclonal antibodies. Res Sq. doi:10.21203/

ECDC. (2021, April 8, 2021). Reinfection with SARS-CoV-2: implementation of a surveillance case definition within the EU/EEA. Retrieved from

Edara, V. V., Floyd, K., Lai, L., Gardner, M., Hudson, W., Piantadosi, A.,... Suthar, M. S. (2021). Infection and mRNA-1273 vaccine antibodies neutralize SARS-CoV-2 UK variant. medRxiv. doi:10.1101/2021.02.02.21250799

Eguia, E., Crawford, K. H. D., Stevens-Ayers, T., Kelnhofer-Millevolte, L., Greninger, A. L., Englund, J. A.,... Bloom, E. D. A human coronavirus evolves antigenically to escape antibody immunity. Preprint bioRxiv.

Erber, J., Kappler, V., Haller, B., Mijočević, H., Galhoz, A., da Costa, C. P.,... Lingor, P. (2020). Strategies for infection control and prevalence of anti-SARS-CoV-2 IgG in 4,554 employees of a university hospital in Munich, Germany. Preprint medRxiv doi:10.1101/2020.10.04.20206136

European Centre for Disease Control and Prevention. (2020). Guidance for discharge and ending of isolation of people with COVID-19. Retrieved from

European Centre for Disease Control and Prevention. (2020). Infection prevention and control and preparedness for COVID-19 in healthcare settings. Retrieved from

Evans, S., Agnew, E., Vynnycky, E., & Robotham, J. V. (2020). The impact of testing and infection prevention and control strategies on within-hospital transmission dynamics of covid-19 in English hospitals. Preprint medRxiv doi:10.1101/2020.05.12.20095562

Fears, A. C., Klimstra, W. B., Duprex, P., Hartman, A., Weaver, S. C., Plante, K. S.,... Roy, C. J. (2020). Persistence of Severe Acute Respiratory Syndrome Coronavirus 2 in Aerosol Suspensions. Emerg Infect Dis, 26(9). doi:10.3201/eid2609.201806

Focosi, D., & Maggi, F. (2021). Neutralising antibody escape of SARS-CoV-2 spike protein: Risk assessment for antibody-based Covid-19 therapeutics and vaccines. Rev Med Virol. doi:10.1002/rmv.2231

Frampton, D., Rampling, T., Cross, A., Bailey, H., Heaney, J., Byott, M., & Nastouli, E. (2021). Genomic characteristics and clinical effect of the emergent SARS-CoV-2 B.1.1.7 lineage in London, UK: a whole genome sequencing and hospital-based cohort study. The Lancet Infectious Diseases.

Galanis, P., Vraka, I., Fragkou, D., Bilali, A., & Kaitelidou, D. (2020). Seroprevalence of SARS-CoV-2 Antibodies and Associated Factors in Health Care Workers: A Systematic Review and Meta-Analysis. J Hosp Infect. doi:10.1016/j.jhin.2020.11.008 Epub ahead of print.

Garcia-Beltran, W. F., Lam, E. C., St Denis, K., Nitido, A. D., Garcia, Z. H., Hauser, B. M.,... Balazs, A. B. (2021). Multiple SARS-CoV-2 variants escape neutralization by vaccine-induced humoral immunity. Cell. doi:10.1016/j.cell.2021.03.013

Garzaro, G., Clari, M., Ciocan, C., Grillo, E., Mansour, I., Godono, A.,... Pira, E. (2020). COVID-19 infection and diffusion among the healthcare workforce in a large university-hospital in northwest Italy. Med Lav, 111(3), 184-194. doi:10.23749/mdl.v111i3.9767

Gomez-Ochoa, S., Franco, O. H., Rojas, L. Z., … Muka, T. (2020). COVID-19 in Health-Care Workers: A Living Systematic Review and Meta-Analysis of Prevalence, Risk Factors, Clinical Characteristics, and Outcomes. Am J Epidemiol. doi:10.1093/aje/kwaa191 Epub ahead of print.

Golubchik, T., Lythgoe, K. A., Hall, M., Ferretti, L., Fryer, H. R., MacIntyre-Cockett, M., & Todd, J. A. (2021). Early analysis of a potential link between viral load and the N501Y mutation in the SARS-COV2 spike protein. Preprint medRxiv. doi:10.1101/2021.01.12.20249080

Graham, M. S., Sudre, C. H., Anna May, M. A., Antonelli, M., Murray, B., Varavsky, T., & Ourselin, S. (2021). Changes in symptomatology, reinfection, and transmissibility associated with the SARS-CoV-2 variant B.1.1.7: an ecological study. The Lancet Public Health.

Greaney, A. J., Loes, A. N., Crawford, K. H. D., Starr, T. N., Malone, K. D., Chu, H. Y., & Bloom, J. D. (2021). Comprehensive mapping of mutations in the SARS-CoV-2 receptor-binding domain that affect recognition by polyclonal human plasma antibodies. Cell Host Microbe, 29(3), 463-476 e466. doi:10.1016/j.chom.2021.02.003

Guo, X., Wang, J., Hu, D., Wu, L., Gu, L., Wang, Y.,... Wu, Y. (2020). Survey of COVID-19 disease among orthopaedic surgeons in Wuhan, People's Republic of China. J Bone Joint Surg Am, 102(10), 847-854. doi:10.2106/JBJS.20.00417

Hall, V. J., Foulkes, S., Saei, A., Andrews, N., Oguti, B., Charlett, A.,... Hopkins, S. (2021). Effectiveness of BNT162b2 mRNA Vaccine Against Infection and COVID-19 Vaccine Coverage in Healthcare Workers in England, Multicentre Prospective Cohort Study (the SIREN Study). Prerint SSRN. doi:10.2139/ssrn.3790399

Hamner, L., Dubbel, P., Capron, I., Ross, A., Jordan, A., Lee, J.,... Leibrand, H. (2020). High SARS-CoV-2 Attack Rate Following Exposure at a Choir Practice - Skagit County, Washington, March 2020. MMWR Morb Mortal Wkly Rep, 69(19), 606-610. doi:10.15585/mmwr.mm6919e6

Harrington, D., Kele, B., Pereira, S., Couto-Parada, X., Riddell, A., Forbes, S.,... Cutino-Moguel, T. (2021). Confirmed Reinfection with SARS-CoV-2 Variant VOC-202012/01. Clin Infect Dis. doi:10.1093/cid/ciab014

Hawkins, E. S., Fertel, B. S., Muir, M. R., Meldon, S. W., Delgado, F. J., & Smalley, C. M. (2020). Adding eye protection to universal masking reduces covid-19 among frontline emergency clinicians to the level of community spread. Am J Emerg Med. doi:10.1016/j.ajem.2020.08.064 Epub ahead of print.

Hoffman, M., Arora, P., GroB, R., Seidel, A., NHornich, B., Hahn, A., & Pohlmann, S. (2021). SARS-CoV2 variants B.1.351 and B.1.1.248: Escape from therapeutic antibodies and antibodies induced by infection and vaccination. Preprint bioRxiv. doi:10.1101/2021.02.11.430787

Hou, Y. J., Chiba, S., Halfmann, P., Ehre, C., Kuroda, M., Dinnon, K. H., 3rd,... Baric, R. S. (2020). SARS-CoV-2 D614G variant exhibits efficient replication ex vivo and transmission in vivo. Science, 370(6523), 1464-1468. doi:10.1126/science.abe8499

Hyams, C., Marlow, R., Maseko, Z., Ward, L., Fox, K., & Finn, A. (2021). Assessing the Effectiveness of BNT162b2 and ChAdOx1nCoV-19 COVID-19 Vaccination in Prevention of Hospitalisations in Elderly and Frail Adults: A Single Centre Test Negative Case-Control Study. Preprint SSRN. doi:10.2139/ssrn.3796835

Huang, Q., Mondal, A., Jiang, X., Horn, M. A., Fan, F., Fu, P.,... Gurarie, D. (2020). SARS-CoV-2 transmission and control in a hospital setting: An individual-based modelling study. Preprint medRxiv doi:10.1101/2020.08.22.20179929

Huang, Z., Zhao, S., Li, Z., Chen, W., Zhao, L., Deng, L., & Song, B. (2020). The battle against coronavirus disease 2019 (COVID-19): Emergency management and infection control in a radiology department. J Am Coll Radiol, 17(6), 710-716. doi:10.1016/j.jacr.2020.03.011.

ICEG. (2020). COVID-19 Guidance on the use of personal protective equipment by health care workers in areas with significant community transmission. Retrieved from

ICEG. (2020). COVID-19 Infection Prevention and Control for Residential Care Facilities. Retrieved from

ICEG. (2021, April 14, 2021). New variants of SARS-CoV-2 and implications for infection prevention and control practices. A statement from the Infection Control Expert Group (ICEG) on transmission of SARS-CoV-2. Retrieved from implications-for-infection-prevention-and-control-practices

Jang, S., Han, S. H., & Rhee, J. Y. (2020). Cluster of Coronavirus Disease Associated with Fitness Dance Classes, South Korea. Emerg Infect Dis, 26(8), 1917-1920. doi:10.3201/eid2608.200633

Jespersen, S., Mikkelsen, S., Greve, T., Kaspersen, K. A., Tolstrup, M., Boldsen, J. K.,... Erikstrup, C. (2020). SARS-CoV-2 seroprevalence survey among 18,000 healthcare and administrative personnel at hospitals, pre-hospital services, and specialist practitioners in the central Denmark region. Clin Infect Dis. doi:10.1093/cid/ciaa1471 Epub ahead of print.

Jiaqiang, Z., Mingyang, S., Weijia, Z., Ningtao, L., MingZhang, Z., Lei, Q., & Szu-Yuan, W. (2020). Predictive factors of transmission during endotracheal intubation for coronavirus disease 2019 (COVID-19). Preprint SSRN doi:10.22139/ssrn.3557990

Jin, Y.H., Huang, Q., Wang, Y.Y., Zeng, X.T., Luo, L.S., Pan, Z.Y.,... Wang, X.-H. (2020). Perceived infection transmission routes, infection control practices, psychosocial changes, and management of COVID-19 infected healthcare workers in a tertiary acute care hospital in Wuhan: A cross-sectional survey. Mil Med Res, 7(1), 24. doi:10.1186/s40779-020-00254-8

Jones, C. R., Hamilton, F. W., Thompson, A., Morris, T. T., & Moran, E. (2020). Seroprevalence of SARS-CoV-2 IgG in healthcare workers and other staff at North Bristol NHS Trust: A sociodemographic analysis. J Infect. doi:10.1016/j.jinf.2020.11.036 Epub ahead of print

Kidd, M., Richter, A., Best, A., Cumley, N., Mirza, J., Percival, B.,... McNally, A. (2021). S-variant SARS CoV-2 lineage B1.1.7 is associated with significantly higher viral loads in samples tested by ThermoFisher TaqPath RT-qPCR. J Infect Dis. doi:10.1093/infdis/jiab082

Kim, S. W., Jo, S. J., Lee, H., Oh, J. H., Lim, J., Lee, S. H.,... Lee, J. (2020). Containment of a healthcare-associated covid-19 outbreak in a university hospital in Seoul, Korea: A single-center experience. PLoS One. 15(8), e0237692. doi:10.1371/journal.pone.0237692 Epub ahead of print.

King, M.F., Wilson, A. M., Weir, M. H., Lopez-Garcia, M., Proctor, J.,... Noakes, C. J. (2020). Modelling the risk of SARS-CoV-2 infection through PPE doffing in a hospital environment. Preprint medRxiv doi:10.1101/2020.09.20.20197368

Knoll, R. L., Klopp, J., Bonewitz, G., Grondahl, B., Hilbert, K., Kohnen, W.,... Gehring, S. (2020). Containment of a large SARS-CoV-2 outbreak among healthcare workers in a pediatric intensive care unit. Pediatr Infect Dis J, 39(11), e336-e339. doi:10.1097/INF.0000000000002866

Koh, W. C., Naing, L., Chaw, L., Rosledzana, M. A., Alikhan, M. F., Jamaludin, S. A.,... Wong, J. (2020). What do we know about SARS-CoV-2 transmission? A systematic review and meta-analysis of the secondary attack rate and associated risk factors. PLoS One, 15(10), e0240205-e0240205. doi:10.1371/journal.pone.0240205

Laffeber, C., de Koning, K., Kanaar, R., & Lebbink, E. H. G. (2021). Experimental evidence for enhanced receptor binding by rapidly spreading SARS-CoV-2 variants. Preprint bioRxiv. doi:10.1101/2021.02.22.432357

Lai, X., Wang, M., Qin, C., Tan, L., Ran, L., Chen, D.,... Wang, W. (2020). Coronavirus disease 2019 (COVID-2019) infection among health care workers and implications for prevention measures in a tertiary hospital in Wuhan, China. JAMA Netw Open, 3(5), e209666. doi:10.1001/jamanetworkopen.2020.9666

Lednicky, J. A., Lauzardo, M., Fan, Z. H., Jutla, A., Tilly, T. B., Gangwar, M.,... Wu, C. Y. (2020). Viable SARS-CoV-2 in the air of a hospital room with COVID-19 patients. Int J Infect Dis, 100, 476-482. doi:10.1016/j.ijid.2020.09.025

Lee, S., Kim, T., Lee, E., Lee, C., Kim, H., Rhee, H.,... Kim, T. H. (2020). Clinical Course and Molecular Viral Shedding Among Asymptomatic and Symptomatic Patients With SARS-CoV-2 Infection in a Community Treatment Center in the Republic of Korea. JAMA Intern Med. doi:10.1001/jamainternmed.2020.3862

Leung, K., Shum, M. H., Leung, G. M., Lam, T. T., & Wu, J. T. (2021). Early transmissibility assessment of the N501Y mutant strains of SARS-CoV-2 in the United Kingdom, October to November 2020. Euro Surveill, 26(1). doi:10.2807/1560-7917.ES.2020.26.1.2002106

Li, Q., Nie, J., Wu, J., Zhang, L., Ding, R., Wang, H.,... Wang, Y. (2021). SARS-CoV-2 501Y.V2 variants lack higher infectivity but do have immune escape. Cell. doi:10.1016/j.cell.2021.02.042

Licina A., Silvers, A. J., & Stuart, R. (2020). Use of powered air-purifying respirator(papr) by healthcare workers for preventing highly infectious viral diseases -a systematic review of evidence. Syst Rev, 9(1), 173. doi:10.1186/s13643-020-01431-5

Liu, Y., Liu, J., Xia, H., Zhang, X., Fontes-Garfias, C. R., Swanson, K. A.,... Shi, P. Y. (2021). Neutralizing Activity of BNT162b2-Elicited Serum. N Engl J Med. doi:10.1056/NEJMc2102017

Liu, Y., Ning, Z., Chen, Y., Guo, M., Liu, Y., Gali, N. K.,... Lan, K. (2020). Aerodynamic analysis of SARS-CoV-2 in two Wuhan hospitals. Nature, 582(7813), 557-560. doi:10.1038/s41586-020-2271-3

Lu, J., Gu, J., Li, K., Xu, C., Su, W., Lai, Z.,... Yang, Z. (2020). COVID-19 Outbreak Associated with Air Conditioning in Restaurant, Guangzhou, China, 2020. Emerg Infect Dis, 26(7), 1628-1631. doi:10.3201/eid2607.200764

Lu, J., & Yang, Z. (2020). COVID-19 Outbreak Associated with Air Conditioning in Restaurant, Guangzhou, China, 2020. Emerg Infect Dis, 26(11), 2791-2793. doi:10.3201/eid2611.203774

Luong-Nguyen, M., Hermand, H., Abdalla, S., Cabrit, N., Hobeika, C., Brouquet, A.,... Sauvanet, A. (2020). Nosocomial infection with SARS-CoV-2 within departments of digestive surgery. J Visc Surg, 157(3S1), S13-S18. doi:10.1016/j.jviscsurg.2020.04.016

Luqman Arafath, T. K., Jubbal, S. S., Gireesh, E. D., Margapuri, J., Jogu, H. R.,... Penupolu, S. (2020). Risk of transmission of infection to healthcare workers delivering supportive care for coronavirus pneumonia; a rapid GRADE review. Preprint medRxiv doi:10.1101/2020.07.06.20146712

Lynch, J. B., Davitkov, P., Anderson, D. J., Bhimraj, A., Cheng, V. C., Guzman-Cottrill, J.,... Sultan, S. (2020). Infectious Diseases Society of America Guidelines on Infection Prevention for Health Care Personnel Caring for Patients with Suspected or Known COVID-19

Madhi, S. A., Baillie, V., Cutland, C. L., Voysey, M., Koen, A. L., Fairlie, L.,... Group, N.-S. G. W.-V. C. (2021). Efficacy of the ChAdOx1 nCoV-19 Covid-19 Vaccine against the B.1.351 Variant. N Engl J Med. doi:10.1056/NEJMoa2102214

Muik, A., Wallisch, A. K., Sanger, B., Swanson, K. A., Muhl, J., Chen, W.,... Sahin, U. (2021). Neutralization of SARS-CoV-2 lineage B.1.1.7 pseudovirus by BNT162b2 vaccine-elicited human sera. Science, 371(6534), 1152-1153. doi:10.1126/science.abg6105

Mandić-Rajčević, S., Masci, F., Crespi, E., Franchetti, S., Longo, A., Bollina, I.,... Colosio, C. (2020). Contact tracing and isolation of asymptomatic spreaders to successfully control the COVID-19 epidemic among healthcare workers in Milan (Italy). Preprint medRxiv doi:10.1101/2020.05.03.20082818

Miller, J.C., Qiu, X., MacFadden, D., & Hanage, W.P. (2020). Evaluating the contributions of strategies to prevent SARS-CoV-2 transmission in healthcare setting: a modelling study. Preprint medRxiv doi:10.1101/2020.04.20.20073080

Morawska, L., & Milton, D. K. (2020). It is Time to Address Airborne Transmission of COVID-19. Clin Infect Dis 71(9), 2311-2313. doi:10.1093/cid/ciaa939

Morcuende, M., Guglielminotti, J., & Landau, R. (2020). Anesthesiologists' and intensive care providers' exposure to covid-19 infection in a new york city academic center: A prospective cohort study assessing symptoms and covid-19 antibody testing. Anesthesia & Analgesia, 131(3), 669-676. doi:10.1213/ANE.0000000000005056

Mortgat, L., Barbezange, C., Fischer, N., Heyndrickx, L., Hutse, V., Thomas, I.,... Duysburgh, E. (2020). SARS-CoV-2 prevalence and seroprevalence among healthcare workers in Belgian hospitals: Baseline results of a prospective cohort study. Preprint medRxiv doi:10.1101/2020.10.03.20204545

Mponponsuo, K., Kerkerian, G., Somayaji, R., Missaghi, B., Vayalumkal, J. V., Larios, O. E.,... Conly, J. (2020). Lack of nosocomial transmission to exposed inpatients and coworkers in an investigation of five SARS-CoV-2-infected healthcare workers. Infect Control Hosp Epidemiol. doi:10.1017/ice.2020.392 Epub ahead of print.

Nasia, S., Gage, K. M., Katarina, M. B., Thomas, C. F., & David, H. O. C. (2020). Determining the source of transmission of SARS-CoV-2 infection in a healthcare worker. Preprint medRxiv doi:10.1101/2020.04.27.20077016

Naveca, F., da Costa, C., Nascimento, V., Souza, V., Corado, A., Nascimento, F., &

Resende, P. C. (2021). SARS‐CoV‐2 reinfection by the new variant of concern (VOC) P.1 in Amazonas, Brazil. Retrieved from

NERVTAG. (2021, January 22, 2021). NERVTAG paper on COVID-19 variant of concern B.1.1.7. Retrieved from concern-b117

Nishida, T., Iwahashi, H., Yamauchi, K., Kinoshita, N., Okauchi, Y., Suzuki, N.,... Abe, K. (2020). Seroprevalence of SARS-CoV-2 antibodies among 925 staff members in an urban hospital accepting COVID-19 patients in Osaka prefecture, Japan. Preprint medRxiv doi:10.1101/2020.09.10.20191866

O'Keefe, J., Freeman, S., & Nicol, A. (2021). National Collaborating Centre for Environmental Health (NCCEH). The Basics of SARS-CoV-2 Transmission. Accessed on May 10, 2021.

Ong, S. W. X., Tan, Y. K., Chia, P. Y., Lee, T. H., Ng, O. T., Wong, M. S. Y., & Marimuthu, K. (2020). Air, Surface Environmental, and Personal Protective Equipment Contamination by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) From a Symptomatic Patient. JAMA, 323(16), 1610-1612. doi:10.1001/jama.2020.3227

Ontario Agency for Health Protection and Promotion (Public Health Ontario), Provincial Infectious Diseases Advisory Committee. Interim guidance for infection prevention and control of SARS-CoV-2 variants of concern for health care settings. 1st revision. Toronto, ON: Queen's Printer for Ontario; 2021.

Oran, D. P., & Topol, E. J. (2020). Prevalence of Asymptomatic SARS-CoV-2 Infection : A Narrative Review. Ann Intern Med, 173(5), 362-367. doi:10.7326/M20-3012

Park, S. Y., Kim, Y. M., Yi, S., Lee, S., Na, B. J., Kim, C. B.,... Jeong, E. K. (2020). Coronavirus Disease Outbreak in Call Center, South Korea. Emerg Infect Dis, 26(8), 1666-1670. doi:10.3201/eid2608.201274

Pawlowski, C., Lenehan, P., Puranik, V., Venkatakrishnan, A. J., Niewsen, M. J. M., O''Horo, J. C., & Soundararajan, V. (2021). FDA-authorized COVID-19 vaccines are effective per real-world evidence synthesized across a multi-state health system. Preprint medRxiv. doi:10.1101/2021.02.15.21251623

PHE. (2021, January 14, 2021). Investigation of novel SARS-CoV-2 variant - Variant of Concer 202012/01. Retrieved from

Planas, D., Bruel, T., Grzelak, L., Guivel-Benhassine, F., Staropoli, I., Porrot, F.,... Schwartz, O. (2021). Sensitivity of infectious SARS-CoV-2 B.1.1.7 and B.1.351 variants to neutralizing antibodies. Nat Med. doi:10.1038/s41591-021-01318-5

Polack, F. P., Thomas, S. J., Kitchin, N., Absalon, J., Gurtman, A., Lockhart, S.,... Group, C. C. T. (2020). Safety and Efficacy of the BNT162b2 mRNA Covid-19 Vaccine. N Engl J Med, 383(27), 2603 2615. doi:10.1056/NEJMoa2034577

Prasitsirikul, W., Pongpirul, K., Pongpirul, W. A., Panitantum, N., Ratnarathon, A. C., & Hemachudha, T. (2020). Nurse infected with COVID-19 from a provisional dengue patient. Emerg Microbes Infect, 9(1), 1354-1355. doi:10.1080/22221751.2020.1775131

Public Health Agency of Canada. (2012). Hand Hygiene Practices in Healthcare Settings. /content/canadasite/en/public-health/services/infectious-diseases/nosocomial-occupational-infections/hand-hygiene-practices-healthcare-settings.html

Public Health Agency of Canada. (2013). Routine Practices and Additional Precautions for Preventing the Transmission of Infection in Healthcare Settings.

Public Health Agency of Canada. (2018). Infection Prevention and Control Guidance for Middle East Respiratory Syndrome Coronavirus (MERS-CoV) in Acute Care Settings. /content/canadasite/en/public-health/services/publications/diseases-conditions/infection-prevention-control-guidance-middle-east-respiratory-syndrome-coronavirus-mers-cov-acute-care-settings.html

Public Health England/National Health Service. (2020). COVID-19: Guidance for the remobilisation of services within health and care settings. Retrieved from

Resende, P. C. (2021). Spike E484K Mutation in the First SARS-CoV-2 Reinfection Case Confirmed in Brazil, 2020. Retrieved from reinfection-case-confirmed-in-brazil-2020/584

Rickman, H. M., Rampling, T., Shaw, K., Martinez-Garcia, G., Hail, L., Coen, P.,... Houlihan, C. F. (2020). Nosocomial transmission of COVID-19: A retrospective study of 66 hospital-acquired cases in a London teaching hospital. Clin Infect Dis. doi:10.1093/cid/ciaa816 Epub ahead of print.

Sabino, E. C., Buss, L. F., Carvalho, M. P. S., Prete, C. A., Jr., Crispim, M. A. E., Fraiji, N. A.,... Faria, N. R. (2021). Resurgence of COVID-19 in Manaus, Brazil, despite high seroprevalence. Lancet, 397(10273), 452-455. doi:10.1016/S0140-6736(21)00183-5

SARS‐CoV‐2 reinfection by the new variant of concern (VOC) P.1 in Amazonas, Brazil. (2021). Retrieved from new-variant-of-concern-voc-p-1-in-amazonas-brazil/596

Schmitz, D., Vos, M., Stolmeijer, R., Lameijer, H., Schonberger, T., Gaakeer, M. I.,... Ter Avest, E. (2020). Association between personal protective equipment and SARS-CoV-2 infection risk in emergency department healthcare workers. doi:10.1097/MEJ.0000000000000766 Eur J Emerg Med. Epub ahead of print.

Schwartz, C., Oster, Y., Slama, C., Benenson, S., & Hadassah, C.-I. W. G. (2020). A dynamic response to exposures of health care workers to newly diagnosed COVID-19 patients or hospital personnel, in order to minimize cross-transmission and the need for suspension from work during the outbreak. Open Forum Infect Dis, 7(9), ofaa384. doi:10.1093/ofid/ofaa384

Schwierzeck, V., König, J. C., Kühn, J., Mellmann, A., Correa-Martínez, C. L., Omran, H.,... Kampmeier, S. (2020). First reported nosocomial outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in a pediatric dialysis unit. Clinical infectious diseases: an official publication of the Infectious Diseases Society of America. Clin Infect Dis. doi:10.1093/cid/ciaa491 Epub ahead of print.

Seidelman, J. L., Lewis, S. S., Advani, S. D., Akinboyo, I. C., Epling, C., Case, M.,... Smith, B. A. (2020). Universal masking is an effective strategy to flatten the severe acute respiratory coronavirus virus 2 (SARS-CoV-2) healthcare worker epidemiologic curve. Infect Control Hosp Epidemiol, 1-2. doi:10.1017/ice.2020.313

Shen, Y., Li, C., Dong, H., Wang, Z., Martinez, L., Sun, Z.,... Xu, G. (2020). Community Outbreak Investigation of SARS-CoV-2 Transmission Among Bus Riders in Eastern China. JAMA Intern Med. doi:10.1001/jamainternmed.2020.5225 Epub ahead of print

Sikkema, R. S., Pas, S. D., Nieuwenhuijse, D. F., Toole, Á., Verweij, J., van der Linden, A.,... Koopmans, M. P. G. (2020). COVID-19 in health-care workers in three hospitals in the south of the Netherlands: A cross-sectional study. Lancet Infect Dis, 20(11), 1273-1280. doi:10.1016/S1473-3099(20)30527-2

Somsen, G. A., van Rijn, C., Kooij, S., Bem, R. A., & Bonn, D. (2020). Small droplet aerosols in poorly ventilated spaces and SARS-CoV-2 transmission. Lancet Respir Med, 8(7), 658-659. doi:10.1016/S2213-2600(20)30245-9

Stadnytskyi V, Bax CE, Bax A, Anfinrud P. The airborne lifetime of small speech droplets and their potential importance in SARS-CoV-2 transmission. Proc Ntl Acad Sci. 2020;117:11875-7. doi:10.1073/pnas.2006874117

Stamatatos, L., Czartoski, J., Wan, Y. H., Homad, L. J., Rubin, V., Glantz, H.,... McGuire, A. T. (2021). mRNA vaccination boosts cross-variant neutralizing antibodies elicited by SARS-CoV-2 infection. Science. doi:10.1126/science.abg9175

Tada, T., Dcosta, B. M., Samanovic-Golden, M., Herati, R. S., Cornelius, A., Mulligan, M. J., & Landau, N. R. (2021). Neutralization of viruses with European, South African, and United States SARS-CoV-2 variant spike proteins by convalescent sera and BNT162b2 mRNA vaccine-elicited antibodies. Preprint bioRxiv. doi:10.1101/2021.02.05.430003

Tande, A. J., Pollock, B. D., Shah, N. D., Farrugia, G., Virk, A., Swift, M.,... Berbari, E. F. (2021). Impact of the COVID-19 Vaccine on Asymptomatic Infection Among Patients Undergoing Pre-Procedural COVID-19 Molecular Screening. Clin Infect Dis. doi:10.1093/cid/ciab229

Tran, K., Cimon, K., Severn, M., Pessoa-Silva, C. L., & Conly, J. (2012). Aerosol generating procedures and risk of transmission of acute respiratory infections to healthcare workers: a systematic review. PLoS One, 7(4), e35797. doi:10.1371/journal.pone.0035797

Tubiana, S., Burdet, C., Houhou, N., Thy, M., Manchon, P., Blanquart, F.,... Duval, X. (2020). High-risk exposure without personal protective equipment and infection with SARS-CoV-2 in healthcare workers: Results of the CoV-CONTACT prospective cohort. Preprint medRxiv doi:10.1101/2020.09.17.20194860

Turcato, G., Zaboli, A., & Pfeifer, N. (2020). The COVID-19 epidemic and reorganisation of triage, an observational study. Inter Emerg Med, 15(8), 1517-1524. doi:10.1007/s11739-020-02465-2

Vaseleiou, E., Simpson, C. R., Robertson, C., Shi, T., Kerr, S., Agrawal, U., & Sheikh, A. (2021). Effectiveness of First Dose of COVID-19 Vaccines Against Hospital Admissions in Scotland: National Prospective Cohort Study of 5.4 Million People. Preprint SSRN. doi:10.2139/ssrn.3789264

Vasques Nonaka, C. K., Miranda Franco, M., Graf, T., Almeida Mendes, A. V., Santana de Aquiar, R., Giiovanetti, M., & Solano de Freitas Souza, B. (2021). Genomic evidence of a SARS-CoV-2 reinfection case with E484K spike mutation in Brazil. Preprint ( doi: 10.20944/preprints202101.0132.v1

van Doremalen, N., Bushmaker, T., Morris, D. H., Holbrook, M. G., Gamble, A., Williamson, B. N.,... Munster, V. J. (2020). Aerosol and Surface Stability of SARS-CoV-2 as Compared with SARS-CoV-1. N Engl J Med, 382(16), 1564-1567. doi:10.1056/NEJMc2004973

van Kampen, J. J. A., van de Vijver, D. A. M. C., Fraaji, P. L. A., KHaagmans, B. L., Lamers, M. M., Okba, N.,... van der Eijk, A. A. (2020). Shedding of infectious virus in hospitalized patients with coronavirus disease-2019 (COVID-19): duration and key determinants. Preprint medRxiv doi:10.1101/2020.06.08.20125310

Volz, E., Hill, V., McCrone, J. T., Price, A., Jorgensen, D., O'Toole, A.,... Connor, T. R. (2021). Evaluating the Effects of SARS-CoV-2 Spike Mutation D614G on Transmissibility and Pathogenicity. Cell, 184(1), 64-75 e11. doi:10.1016/j.cell.2020.11.020

Voysey, M., Clemens, S. A. C., Madhi, S. A., Weckx, L. Y., Folegatti, P. M., Aley, P. K.,... Oxford, C.V.T.G. (2021). Safety and efficacy of the ChAdOx1 nCoV-19 vaccine (AZD1222) against SARS-CoV-2: an interim analysis of four randomised controlled trials in Brazil, South Africa, and the UK. Lancet, 397(10269), 99-111. doi:10.1016/S0140-6736(20)32661-1

Wake, R. M., Morgan, M., Choi, J., & Winn, S. (2020). Reducing nosocomial transmission of covid-19: Implementation of a covid-19 triage system. Clin Med (Lond), 20(5), e141-e145. doi:10.7861/clinmed.2020-0411

Wang, P., Nair, M. S., Liu, L., Iketani, S., Luo, Y., Guo, Y.,... Ho, D. D. (2021). Increased Resistance of SARS-CoV-2 Variants B.1.351 and B.1.1.7 to Antibody Neutralization. Preprint bioRxiv. doi:10.1101/2021.01.25.428137

Wang, Q., Huang, X., Bai, Y., Wang, X., Wang, H., Hu, X.,... Zhao, H. (2020). Epidemiological characteristics of covid-19 in medical staff members of neurosurgery departments in Hubei province: A multicentre descriptive study. Preprint medRxiv doi:10.1101/2020.04.20.20064899

Wang, X., Ferro, E. G., Zhou, G., Hashimoto, D., & Bhatt, D. L. (2020). Association Between Universal Masking in a Health Care System and SARS-CoV-2 Positivity Among Health Care Workers. JAMA, 324(7), 703-4. doi:10.1001/jama.2020.12897

Wang, Y., Wu, W., Cheng, Z., Tan, X., Yang, Z., Zeng, X.,... Wang, X. (2020). Super-factors associated with transmission of occupational covid-19 infection among healthcare staff in Wuhan, China. J Hosp Infect, 106(1), 25-34. doi:10.1016/j.jhin.2020.06.023

Wang, Z., Schmidt, F., Weisblum, Y., Muecksch, F., Barnes, C. O., Finkin, S.,... Nussenzweig, M. C. (2021). mRNA vaccine-elicited antibodies to SARS-CoV-2 and circulating variants. Nature. doi:10.1038/s41586-021-03324-6

Wee, L. E. I., Sim, X. Y. J., Conceicao, E. P., Aung, M. K., Tan, K. Y., Ko, K. K. K.,... Ling, M. L. (2020). Containing covid-19 outside the isolation ward: The impact of an infection control bundle on environmental contamination and transmission in a cohorted general ward. Am J Infect Control, 48(9), 1056-1061. doi:10.1016/j.ajic.2020.06.188

Wee, L. E., Sim, X. Y. J., Conceicao, E. P., Aung, M. K., Goh, J. Q., Yeo, D. W. T.,... Venkatachalam, I. (2020). Containment of covid-19 cases among healthcare workers: The role of surveillance, early detection, and outbreak management. Infect Control Hosp Epidemiol, 41(7), 765-771. doi:10.1017/ice.2020.219

Wei WE LZ, Chiew CJ, Yong SE, Toh MP, Lee VJ. Presymptomatic Transmission of SARS-CoV-2 - Singapore, January 23 - March 16, 2020. MMWR Morb Mortal Wkly Rep 2020;69:411-415. doi:10.15585/mmwr.mm6914e1

Wibmer, C. K., Ayres, F., Hermanus, T., Madzivhandila, M., Kgagudi, P., Oosthuysen, B.,... Moore, P. L. (2021). SARS-CoV-2 501Y.V2 escapes neutralization by South African COVID-19 donor plasma. Nat Med. doi:10.1038/s41591-021-01285-x

WHO. (2020). Infection prevention and control during health care when coronavirus disease (COVID-19) is suspected or confirmed Interim Guidance 29 June 2020. Retrieved from

WHO. (2020). Mask use in the context of COVID-19. Retrieved from

World Health Organization. (2020). Infection prevention and control during health care when coronavirus disease (COVID-19) is suspected or confirmed. Retrieved from

WHO. (2020). Transmission of SARS-CoV-2: implications for infection prevention precautions. Retrieved from

Wilkins, J., Gray, E. L., Wallia, A., Hirschhorn, L., Zembower, T., Ho, J.,... Evans, C. (2020). Seroprevalence and correlates of SARS-CoV-2 antibodies in healthcare workers in Chicago. Open Forum Infect Dis. doi:10.1093/ofid/ofaa582 Epub ahead of print.

Wolfel, R., Corman, V. M., Guggemos, W., Seilmaier, M., Zange, S., Muller, M. A.,... Wendtner, C. (2020). Virological assessment of hospitalized patients with COVID-2019. Nature, 581(7809), 465-469. doi:10.1038/s41586-020-2196-x

Wu, K., Werner, A. P., Moliva, J. I., Ko ch, M., Choi, A., Stewart-Jones, G. B. E.,... Edwards, D. K. (2021). mRNA-1273 vaccine induces neutralizing antibodies against spike mutants from global SARS CoV-2 variants. Preprint bioRxiv. doi:10.1101/2021.01.25.427948

Xie, X., Liu, Y., Liu, J., Zhang, X., Zou, J., Fontes-Garfias, C. R.,... Shi, P. Y. (2021). Neutralization of SARS-CoV-2 spike 69/70 deletion, E484K and N501Y variants by BNT162b2 vaccine-elicited sera. Nat Med. doi:10.1038/s41591-021-01270-4

Xie, X., Zou, J., Fontes-Garfias, C. R., Xia, H., Swanson, K. A., Cutler, M.,... Dormitzer, P. R., Shi, P-Y. (2021). Neutralization of N501Y mutant SARS-CoV-2 by BNT162b2 vaccine-elicited sera. Preprint bioRxiv. doi:10.1101/2021.01.07.425740

Yu, I. T., Li, Y., Wong, T. W., Tam, W., Chan, A. T., Lee, J. H.,... Ho, T. (2004). Evidence of airborne transmission of the severe acute respiratory syndrome virus. N Engl J Med, 350(17), 1731-1739. doi:10.1056/NEJMoa032867

Zheng, C., Hafezi-Bakhtiari, N., Cooper, V., Davidson, H., Habibi, M., Riley, P., & Breathnach, A. (2020). Characteristics and transmission dynamics of COVID-19 in healthcare workers at a London teaching hospital. J Hosp Infect, 106(2), 325-329. doi:10.1016/j.jhin.2020.07.025

Zhang, W., Davis, B. D., Chen, S. S., Sincuir Martinez, J. M., Plummer, J. T., & Vail, E. (2021).Emergence of a Novel SARS-CoV-2 Variant in Southern California. JAMA, 325(13), 1324-1326. doi:10.1001/jama.2021.1612

Zhong, Q., Liu, Y. Y., Luo, Q., Zou, Y. F., Jiang, H. X., Li, H.,... Zhang, Z. Z. (2020). Spinal anaesthesia for patients with coronavirus disease 2019 and possible transmission rates in anaesthetists: Retrospective, single-centre, observational cohort study. Br J Anaesth, 124(6), 670-675. doi:10.1016/j.bja.2020.03.007

Zucman, N., Uhel, F., Descamps, D., Roux, D., & Ricard, J. D. (2021). Severe reinfection with South African SARS-CoV-2 variant 501Y.V2: A case report. Clin Infect Dis. doi:10.1093/cid/ciab129

Page details

Date modified: