At last, health, aged care and quarantine workers get the right masks to protect against airborne coronavirus
- Written by C Raina MacIntyre, Professor of Global Biosecurity, NHMRC Principal Research Fellow, Head, Biosecurity Program, Kirby Institute, UNSW
Almost a year ago, in July 2020, our calls[1] for the government to urgently upgrade the guidelines to protect health workers from airborne SARS-CoV-2 fell on deaf ears.
The existing guidelines said health providers working around COVID-19 patients should wear a surgical mask. It restricted use of the more protective P2 or N95 masks[2], which stop airborne particles getting through, to very limited scenarios. These involved “aerosol-generating procedures”, such as inserting a breathing tube. This was expanded slightly in August 2020 but still left most health workers without access to P2/N95 masks.
More than 4,000[3] Australian health workers were infected by COVID-19 during the Victorian second wave. Health authorities denied the importance of airborne transmission and blamed[4] clinical staff for “poor habits” and “apathy”. Health workers expressed despair and a sense of abandonment[5], cataloguing the opposition they faced to get adequate protection against COVID-19.
Last week, 15 months after the COVID-19 pandemic was declared, the Australian guidelines[6] on personal protective equipment (PPE) for health workers, including masks, were finally revised.
What do the new guidelines say?
The new guidelines expand the range of situations in which P2/N95 masks should be available to staff – essentially anywhere where COVID-19-infected people are expected to be – and remove all references to “aerosol-generating procedures”.
This recognises that breathing, speaking, sneezing and coughing all generate aerosols[7] which can accumulate in indoor spaces, posing a higher risk[8] than “aerosol-generating procedures”.
Read more: Which mask works best? We filmed people coughing and sneezing to find out[9]
“Fit testing” is an annual procedure[10] that should be done for all workers wearing a P2/N95 mask or higher grade respirator, to ensure air can’t leak around the edges.
But this was previously denied to many[11] Australian health workers.
The new guidelines unequivocally state fit-tested P2/N95 masks are required for all staff managing patients with suspected or confirmed COVID-19. This means health workers can finally receive similar levels of respiratory protection[12] to workers on mining and construction sites.
The new guidelines leave ambiguity around which workplaces are within the scope by stating that health care:
may include hospitals, non-inpatient settings, managed quarantine, residential care facilities, COVID-19 testing clinics, in-home care and other environments where clinical care is provided.
The guidelines also allow employers to decide what comprises a high risk and what doesn’t, allowing more wiggle room to deny workers a P2/N95 mask.
N95 masks (top) protect against airborne transmission, while surgical masks (bottom) don’t.
Shutterstock[13]
The guidelines say when a suitable P2/N95 mask can’t be used, a re-usable respirator (powered air purifying respirators, or PAPRs) should be considered.
But the guideline’s claim that a PAPR may not provide any additional protection compared to a “well-sealed” disposable P2/N95 mask, is not accurate. In fact, re-usable respirators such as PAPRs afford a higher level of protection[14] than disposable N95 masks.
The new guidelines should also apply to workers in hotel quarantine – both health care and non-clinical staff. This will help strengthen our biosecurity, as long as they’re interpreted in the most precautionary way.
That means not using the wiggle room that allows workplaces to deem a situation lower risk than it actually is or that their workplace is exempt. When working around a suspected or confirmed COVID-19 case, all workers must be provided with a fit-tested P2/N95 mask. Otherwise they are not protected from inhaling SARS-CoV-2 from the air.
In aged care and health care, where cases linked to quarantine breaches can be amplified and re-seeded to the community, the new guidelines go some way towards better protecting our essential first responders and their patients.
Read more: What's the Delta COVID variant found in Melbourne? Is it more infectious and does it spread more in kids? A virologist explains[15]
Guidelines miss the mark on ventilation
The guidelines fail to explicitly acknowledge COVID-19 spreads through air[16] but nonetheless recommend the use of airborne precautions for staff.
Airborne particles are usually less than 100 microns[17] in diameter and can accumulate indoors, which means they’re an inhalation risk.
The old guidelines focused on “large droplets”, which were thought to fall quickly to the ground and didn’t pose a risk in breathed air. This was based on debunked theories[18] about airborne versus droplet transmission.
The new guidelines fail to comprehensively address ventilation, which is only mentioned in passing with a reference to separate guidelines for health-care facilities[19]. This may not cover aged care or hotel quarantine.
Read more: This is how we should build and staff Victoria's new quarantine facility, say two infection control experts[20]
We must ensure institutions such as hospitals, hotel quarantine facilities, residential care, schools, businesses and public transport have plans to mitigate the airborne risk of COVID-19 and other pandemic viruses through improved ventilation and air filtration.
Australia could follow Germany[21], which has invested €500 million (A$787 million) in improving ventilation in indoor spaces.
Meanwhile, Belgium is mandating the use of carbon dioxide monitors[22] in public spaces such as restaurants and gyms so customers can assess whether the ventilation is adequate.
Cleaning shared air would add an additional layer of protection beyond vaccination and mask-wearing. Secondary benefits[23] include decreased transmission of other respiratory viruses and improved productivity[24] due to higher attention and concentration levels.
No updated advice on hand-washing
The United States Centers for Disease Control and Prevention (CDC) now acknowledges[25] exposure to SARS-CoV-2 occurs through “very fine respiratory droplets and aerosol particles” and states the risk of transmission[26] through touching surfaces is “low”.
Yet this is not acknowledged in the latest Australian health-care guidelines.
Australians have been repeatedly reminded to wash or sanitise their hands, wipe down surfaces and stand behind near-useless plexiglass barriers[27].
The promotion of hand hygiene and cleaning surfaces is not based on science[28], which shows it is the air we breathe that matters most.
Revised public messaging is needed for Australians to understand shared air is the most important risk for COVID-19.
References
- ^ our calls (www.mja.com.au)
- ^ P2 or N95 masks (www.cdc.gov)
- ^ More than 4,000 (www.coronavirus.vic.gov.au)
- ^ blamed (www.theaustralian.com.au)
- ^ expressed despair and a sense of abandonment (bmjleader.bmj.com)
- ^ Australian guidelines (www.health.gov.au)
- ^ generate aerosols (theconversation.com)
- ^ higher risk (associationofanaesthetists-publications.onlinelibrary.wiley.com)
- ^ Which mask works best? We filmed people coughing and sneezing to find out (theconversation.com)
- ^ annual procedure (www.mja.com.au)
- ^ previously denied to many (bmjleader.bmj.com)
- ^ similar levels of respiratory protection (covid19evidence.net.au)
- ^ Shutterstock (www.shutterstock.com)
- ^ higher level of protection (www.osha.gov)
- ^ What's the Delta COVID variant found in Melbourne? Is it more infectious and does it spread more in kids? A virologist explains (theconversation.com)
- ^ spreads through air (theconversation.com)
- ^ usually less than 100 microns (science.sciencemag.org)
- ^ debunked theories (www.wired.com)
- ^ health-care facilities (healthfacilityguidelines.com.au)
- ^ This is how we should build and staff Victoria's new quarantine facility, say two infection control experts (theconversation.com)
- ^ Germany (www.bbc.com)
- ^ mandating the use of carbon dioxide monitors (twitter.com)
- ^ Secondary benefits (science.sciencemag.org)
- ^ improved productivity (www.hup.harvard.edu)
- ^ now acknowledges (www.cdc.gov)
- ^ risk of transmission (www.cdc.gov)
- ^ plexiglass barriers (reason.com)
- ^ not based on science (www.nature.com)
