Communication, transparency key as Canada faces new coronavirus threat

Wendy Glauser

doi:10.1503/cmaj.1095846

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RE: Transmission of Corona Virus by Nebulizer- a serious, underappreciated risk!
Israel Amirav and Michael T Newhouse

Posted on: 03 March 2020
Lack of COVID-19 Transmission on an International Flight
Kevin L Schwartz, Michelle Murti, Michael Finkelstein, Jerome Leis, Alanna Fitzgerald-Husek, Laura Bourns, Hamidah Meghani, Andrea Saunders, Vanessa Allen and Barbara Yaffe

Posted on: 24 February 2020

Posted on: (3 March 2020)

RE: Transmission of Corona Virus by Nebulizer- a serious, underappreciated risk!
Israel Amirav, Pediatric Respirologist, University Of Alberta
Other Contributors:
Michael T Newhouse, Respirologist
The current pandemic of COVID-19 cases demands greater infection control precautions. Nebulizers generate aerosol particles in the size of 1-5 µm that can carry bacteria and viruses into the deep lung. The risk of infection transmission via droplet nuclei and aerosols may increase during nebulizer treatments because of the potential to generate a high volume of respiratory aerosols that may be propelled over a longer distance than that involved in natural dispersion pattern (1). Furthermore, the larger particles may stimulate both patients' and bystanders' cough and thus increase the risk of spreading the disease (2). Nebulizer therapy in patients with pandemic COVID-19 infection has the potential to transmit potentially viable COVID-19 to susceptible bystander hosts.
In recent years there has been a welcome shift, in some centers, from the use of nebulizers to metered dose inhalers (pMDI) with Valved-Holding Chambers (VHCs). In Alberta Canada for example, any order for nebulizer is now restricted and nebulizer is only to be used in the following situations:
1. Severe, life-threatening respiratory disease (e.g., those with severe or impending respiratory arrest, those with hypoventilation or ventilation compromise, continuous nebulization, end-stage COPD, cystic fibrosis); OR
2. Patients who are uncooperative or are unable to follow the directions required for a metered-dose inhaler (MDI) with spacer use; OR
3. Patients with a history of...
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The current pandemic of COVID-19 cases demands greater infection control precautions. Nebulizers generate aerosol particles in the size of 1-5 µm that can carry bacteria and viruses into the deep lung. The risk of infection transmission via droplet nuclei and aerosols may increase during nebulizer treatments because of the potential to generate a high volume of respiratory aerosols that may be propelled over a longer distance than that involved in natural dispersion pattern (1). Furthermore, the larger particles may stimulate both patients' and bystanders' cough and thus increase the risk of spreading the disease (2). Nebulizer therapy in patients with pandemic COVID-19 infection has the potential to transmit potentially viable COVID-19 to susceptible bystander hosts.
In recent years there has been a welcome shift, in some centers, from the use of nebulizers to metered dose inhalers (pMDI) with Valved-Holding Chambers (VHCs). In Alberta Canada for example, any order for nebulizer is now restricted and nebulizer is only to be used in the following situations:
1. Severe, life-threatening respiratory disease (e.g., those with severe or impending respiratory arrest, those with hypoventilation or ventilation compromise, continuous nebulization, end-stage COPD, cystic fibrosis); OR
2. Patients who are uncooperative or are unable to follow the directions required for a metered-dose inhaler (MDI) with spacer use; OR
3. Patients with a history of poor response to MDI with spacer.
However, despite a large body of evidence suggesting their lack of superiority or inferiority, compared to MDI +VHC (3), the nebulizer is still widely used in many healthcare facilities (especially in the USA).
Given the current outbreak of COVID-19, Alberta Health Services (AHS) in Canada has now requested to reconsider any plan or order for a nebulizer therapy. To reduce the risk of transmission of all infectious respiratory illnesses in healthcare facilities we would encourage all caregivers in all other provinces to align with the above restrictions and seriously consider avoiding the use of nebulizers. Keeping our patients and staff safety should be our priority.

References

1. Tang JW, Li Y, Eames I, Chan PKS, Ridgway GL. Factors involved in the aerosol transmission of infection and control of ventilation in healthcare premises. J Hosp Infect 2006;64:100-14.
2. Public Health Agency of Canada. 2011. Prevention and Control of Influenza during a Pandemic for All Healthcare Settings. Annex F. Retrieved from http://www.phac-aspc.gc.ca/cpip-pclcpi/assets/pdf/ann-f-eng.pdf.
3. Cates CJ, Crilly JA, Rowe BH. Holding chambers (spacers) versus nebulisers for beta-agonist treatment of acute asthma.
Cochrane Database of Systematic Reviews 2006, Issue 2. Art. No.: CD000052. DOI: 10.1002/14651858.CD000052.pub2.
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Competing Interests: M. T. Newhouse is employed by InspiRx Pharmaceuticals Inc as the Chief Medical Officer and has patents through InspiRx Pharmaceuticals Inc (6,470.882; 8,119,016; D 689,602; D 685,085; and D 686725; Pending: US 2012/0318261 and 2012/0318265).
Posted on: (24 February 2020)

Lack of COVID-19 Transmission on an International Flight
Kevin L Schwartz, Infectious Disease Physician, Public Health Ontario
Other Contributors:
Michelle Murti, Public Health Physician

Michael Finkelstein, Associate Medical Officer of Health

Jerome Leis, Infectious Disease Physician

Alanna Fitzgerald-Husek, Associate Medical Officer of Health

Laura Bourns, Associate Medical Officer of Health

Hamidah Meghani, Medical Officer of Health

Andrea Saunders, Communicable Diseases Specialist

Vanessa Allen, Chief, Medical Microbiology

Barbara Yaffe, Associate Chief Medical Officer of Health
In response to Wendy Glauser’s article, Communication, transparency key as Canada faces new coronavirus threat, we would like to share the public health response to the first Canadian cases of COVID-19. Case details have been published.(1) The patients traveled from Wuhan to Guangzhou, then Guangzhou to Toronto, Canada, arriving on January 22, 2020. The index patient was symptomatic with dry cough during the flight. His wife developed cough on January 23rd. Both sets of throat and nasopharyngeal swabs collected were positive for COVID-19.

There were approximately 350 passengers on board the airplane. The public was notified through the media that the index case was symptomatic during the 15-hour flight. Close contacts included 25 individuals sitting within two meters of the index case during the flight, flight crew members, and one close contact on arrival in Toronto. Close contacts received active daily contact monitoring by local public health officials for 14 days from the flight. Passengers and crew members who were not from Ontario were referred to their home jurisdiction for follow-up. On January 29th, one close contact developed symptoms of cough; however, nasopharyngeal and throat swabs were negative for COVID-19. Non-close contact passengers were advised to self-monitor and contact public health if symptomatic; five non-close contact symptomatic passengers were tested and found negative by nasopharyngeal and throat swabs for COVID-19.

The United St...
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In response to Wendy Glauser’s article, Communication, transparency key as Canada faces new coronavirus threat, we would like to share the public health response to the first Canadian cases of COVID-19. Case details have been published.(1) The patients traveled from Wuhan to Guangzhou, then Guangzhou to Toronto, Canada, arriving on January 22, 2020. The index patient was symptomatic with dry cough during the flight. His wife developed cough on January 23rd. Both sets of throat and nasopharyngeal swabs collected were positive for COVID-19.

There were approximately 350 passengers on board the airplane. The public was notified through the media that the index case was symptomatic during the 15-hour flight. Close contacts included 25 individuals sitting within two meters of the index case during the flight, flight crew members, and one close contact on arrival in Toronto. Close contacts received active daily contact monitoring by local public health officials for 14 days from the flight. Passengers and crew members who were not from Ontario were referred to their home jurisdiction for follow-up. On January 29th, one close contact developed symptoms of cough; however, nasopharyngeal and throat swabs were negative for COVID-19. Non-close contact passengers were advised to self-monitor and contact public health if symptomatic; five non-close contact symptomatic passengers were tested and found negative by nasopharyngeal and throat swabs for COVID-19.

The United States Centers for Disease Control and Prevention recommends contact tracing two rows in front and behind symptomatic cases with respiratory infections due to an elevated risk within close contact.(2) However, for both SARS-CoV and influenza, approximately 50% of airplane transmission has occurred beyond these rows.(3) Studies of airplane transmission are commonly biased by contacts sharing exposure risks prior to boarding the aircraft.(4) In our investigation, transmission may have been mitigated by mild symptoms and masking during the flight. However, the lack of secondary cases after prolonged air travel exposure supports droplet transmission, not airborne, as the likely route of spread of the COVID-19.

References
1. Silverstein W, Stroud L, Cleghorn G, Leis J. First imported case of 2019 novel coronavirus to Canada presenting as mild pneumonia. Lancet. 2020. Lancet. 2020;EPub Feb 13.
2. Protecting Travelers' Health from Airport to Community: Investigating Contagious Diseases on Flights, Available online at: https://www.cdc.gov/quarantine/contact-investigation.html (accessed February 6, 2020).
3. Hertzberg VS, Weiss H. On the 2-Row Rule for Infectious Disease Transmission on Aircraft. Ann Glob Health. 2016;82:819-23.
4. Leitmeyer K, Adlhoch C. Review Article: Influenza Transmission on Aircraft: A Systematic Literature Review. Epidemiology (Cambridge, Mass.). 2016;27:743-51.
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Competing Interests: None declared.