‘A welcome step’: WHO acknowledges aerosol spread of COVID-19

Anastasia Tsirtsakis

4/05/2021 3:38:22 PM

But experts say the Australian Government’s infection control group must now update its advice to ensure new strategies to reduce transmission risks.

COVID particle breaking apart
According to the WHO, ‘the virus can spread from an infected person’s mouth or nose in small liquid particles when they cough, sneeze, speak, sing or breathe’.

For close to a year, experts have been challenging governments and health authorities to acknowledge the role of aerosol spread in the transmission of COVID-19.
Now, 13 months since the World Health Organization (WHO) declared a pandemic, and the agency has formally recognised that the virus is airborne.
A scientific brief on the WHO’s website, updated on 30 April, reads:
‘The virus can spread from an infected person’s mouth or nose in small liquid particles when they cough, sneeze, speak, sing or breathe. These particles range from larger respiratory droplets to smaller aerosols.’
In addition to spreading at ‘short-range’, the update states that the virus can spread ‘in poorly ventilated and/or crowded indoor settings, where people tend to spend longer periods of time’.
‘This is because aerosols remain suspended in the air or travel farther than one metre (long-range).’
Kate Cole, President-elect of the Australia Institute of Occupational Hygienists, has been a vocal advocate for the formal recognition of aerosol spread. She called the WHO’s acknowledgement is ‘a welcome step’ in the right direction.
‘They’re saying now what we as scientists have been saying for the majority of this pandemic,’ she told newsGP.
‘The challenge now for us in Australia [is that] our official guidance from the Infection Control Expert Group [ICEG] still doesn’t acknowledge airborne transmission or aerosol spread in the same way that WHO does or in keeping with the latest science, unfortunately.
‘What that’s doing is restricting access to airborne precautions or strong safety measures to keep people safe from aerosol spread of COVID, and we’re seeing the results of this, unfortunately, in hotel quarantine.’
The change in WHO’s stance came just a week after researchers urged recognition that COVID-19 is predominantly spread through airborne transmission in a paper published in The Lancet
Others are now calling for ICEG to urgently update its advice, but the Department of Health (DoH) has defended the group, claiming its current guidance is in line with the latest WHO update.
‘Since the beginning of the COVID-19 pandemic, the Infection Control Expert Group (ICEG) has consistently recognised the potential for transmission of SARS-CoV-2 via aerosols in specific circumstances,’ a statement from the DoH to ABC PM reads.
‘Evidence to date suggests that, similar to other respiratory viruses, COVID-19 is mainly transmitted by respiratory droplets which are spread from an infected person to others, during talking, shouting, singing, coughing or sneezing. These droplets can also land on objects or surfaces, so the virus is transmitted through contact with a contaminated surface or object.
‘Experts agree there is a gradient from large droplets to aerosols, however, those who have been in close or direct contact with a COVID-19 case are at highest risk.
‘ICEG also acknowledges the potential for aerosol transmission may be higher under certain conditions, such as poorly ventilated indoor crowded environments.
‘The information provided by WHO in their recently updated Q&A is in line with this advice.’
But Ms Cole says that is ‘inaccurate’.
‘If I look at the statement of transmission that ICEG put out on 19 October last year, I see that they’re only acknowledging aerosols in really specific circumstances [such as] an aerosol-generating procedure,’ she said.
‘Yet scientific studies have repeatedly demonstrated that the paradigm of aerosol-generating procedures is flawed and that we in fact generate more aerosols from day-to-day activities than we do from an aerosol-generating procedure.
‘ICEG are still saying that the most effective measures to protect against COVID transmission are things like good hand hygiene, physical distancing and staying home. They’re really not addressing those key measures that we need to keep people safe from airborne transmission.’
Those measures include higher grade personal protective equipment (PPE), such as fit-tested N95 respirators.
‘At the moment, N95 respirators are being withheld from hotel quarantine in certain areas and they’re only being provided surgical masks. But surgical masks don’t provide protection from airborne spread or aerosols, which is why we see so many outbreaks,’ Ms Cole said.
Melbourne GP Dr Vyom Sharma agrees, saying that guidelines must be updated in line with the evidence.
‘Finally. WHO acknowledges spread of #covid19aus via aerosols at short range. This contradicts the religious belief of some experts that infection at close range implies droplets only – total intellectual dishonesty. Today these people have been exposed,’ he wrote in a tweet.
‘NSW guidelines still say it’s ok stand 1.5 meters back from a patient WITH COVID and WITHOUT A MASK. Literal pseudoscience. Shameful. These experts are homeopaths with medical credentials.’

Along with PPE, ventilation assessments have also been flagged as a crucial step. While some states, including Western Australia more recently, have done so, Ms Cole says action must also be taken on the results.
‘Even though they got that advice, we’ve still got return travellers in hotels that have been assessed as high risk,’ she said.
‘So it’s one thing to do a ventilation assessment, it’s another thing to actually act on those results and ensure that those hotels used for quarantine are fit for purpose.’
Dr Sharma and Ms Cole are among those who have strongly called out the Federal Government’s decision to ban returned travellers from India, suggesting it could have been avoided had it heeded calls on strengthening the hotel quarantine system.
‘I’m really disappointed in our response that we didn’t want to put the effort into strengthening hotel quarantine and we thought it was appropriate to keep Australians in India out of our country,’ Ms Cole said.
‘That particular decision made me incredibly disappointed as an Australian citizen, that that’s what our Government chose to do.
‘It takes a really strong leader … to keep up with the science and move with the times. We’ve seen amazing leaders do that across Australia [with] the likes of [Professor] Brett Sutton, for example, come out publicly and acknowledge it.
‘But, unfortunately, until we see that type of bravery and leadership at the federal level, Australia is probably doomed to continue to see these types of outbreaks in hotel quarantine.’
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