Reducing Aerosol Transmission is an Easy Win to Stop the Spread of COVID
Improving ventilation and upgrading PPE to protect healthcare workers from aerosol transmission will help drive out the Coronavirus sooner, says Dr Nishant Joshi
The SARS-CoV2 virus has resulted in a pandemic that raced across the world at breakneck speed. It has traversed continents via air and boat, raising the question: how can something so small, move so quickly?
If you were to read the above paragraph aloud, you would release a wet mist of tiny particles, mostly invisible to the naked eye. This mist is made up of a combination of ultra-fine aerosols and larger droplets.
When we breathe, the silent and rhythmical waves of our pulmonary system, smooshing alveoli and smooth muscle contractions, allows moisture to leave our body through our mouth and nose. When we talk, pant, even sing, we increase the flapping of our vocal folds which causes higher levels of both aerosol and droplet release.
For years, there has been contention as to how viruses spread and a widespread scientific belief that most respiratory illnesses are transmitted by droplets. These are the larger particles that tend to drop from our mouths and noses to the ground more quickly.
Relatively little mainstream coverage, however, has been afforded to the possibility of airborne transmission. This is when much smaller particles stay suspended in the air for minutes and may flow with air currents.
But, if we understood the extent of aerosol transmission of viruses, this could have profound impacts for how we manage the Coronavirus, as well as help us to prepare for future pandemics.
The Importance of Ventilation
Dr Eilir Hughes, 33, is a GP who works in the small Welsh fishing town of Nefyn. He has been a vocal proponent of the importance of ventilation in managing the spread of the Coronavirus.
“I grew up on a farm, and I understood from my upbringing that ventilation is very important,” he says. “Calves are particularly susceptible to pneumonia and when my father introduced a new ventilation system, rates of pneumonia dropped significantly. That always stuck with me.”
Dr Hughes attended a primary school that was built during the 1930s as an ‘open air’ establishment during the tuberculosis epidemic. “These schools were designed with ventilation in mind,” he says. “Even as a young child, I was reminded that ventilation plays a key role in mitigating infection. And of course, tuberculosis is acknowledged as being airborne.”
Early on in the pandemic, Dr Hughes helped to set up a community assessment centre for around 35,000 people. His local hospital, Bryn Beryl Hospital at Pwllheli, was sequestered for patients who were suspected or confirmed to have the Coronavirus.
“Just before we managed to empty the hospital, Coronavirus sneaked in and roughly 20 nurses became infected,” he says. “This raised the alarm and I felt there was something peculiar about the way in which the virus was spreading.”
This suspicion was compounded when a GP colleague contracted the virus after visiting the hospital, despite wearing a surgical mask which – according to Public Health England guidelines – was adequate personal protective equipment (PPE) at the time. It was starting to look like aerosol transmission was more important to the spread of the virus than initially realised.
Now, with England back in lockdown during its worst yet surge of Coronavirus hospitalisations, important questions need to be asked about how this virus is spreading. Why has the Government failed to keep the Coronavirus under control, let alone come close to eradicating it?
That is why Dr Hughes has embarked on a campaign to bring awareness to ventilation and its impact on virus transmission.
The Requirement of New PPE Masks
The good news is that ventilation is something that should be relatively easy to improve. All governments love the idea of public health resources that are free or cheap, easily accessible, low-risk and high benefit. Improved ventilation fits all of these criteria.
On a local level, Dr Hughes has pioneered a public health message that adds ‘Replace’ to the slogan “Hands. Face. Space.” The idea is to encourage people to consider ventilation alongside handwashing, face coverings and social distancing. He also helped to set up freshair.wales to explain in simple terms the importance of ventilation and offering tips on how public buildings can make simple changes to improve airflow to reduce chains of virus transmission.
As a result of his experiences, Dr Hughes has now pivoted to campaigning for improved PPE for healthcare workers. To date, it is thought that more than 600 health and social care workers have died in the UK due to the Coronavirus. There is a widespread concern that current PPE guidelines may not be suitable for the more contagious new variant of the virus, which has led to a debate over the benefits of wearing cheap and widely available surgical masks to prevent droplet transmission over FFP3 masks. The latter are far more effective at preventing aerosol transmission.
How many pairs of lungs are there in that room? We need to act now.Dr Eilir Hughes
To add to the confusion, the Deputy Chief Medical Officer Professor Jonathan Van-Tam co-authored a 2013 paper which advocated the use of FFP3 masks in a review of the H1N1 pandemic. While “surgical face masks provide a barrier to splashes and droplets impacting on the wearer’s nose, mouth and respiratory tract”, the paper said, “they do not provide protection against airborne (aerosol) particles and are not classed as Respiratory Protective Equipment”. The paper went on to say that “whilst some surgical masks claim to have particulate filtration properties, they do not have the filtering efficiencies required for adequate respiratory protection”.
Dr Hughes has now co-authored an open letter to the Government which has gathered more than 1,000 signatures from frontline doctors and public health experts alike, asking for an urgent change to issue FFP3 masks to all patient-facing health and social care workers. The logic is simple: if we protect the frontline, there will be fewer staff shortages both short-term and long-term, and the virus will be driven out sooner.
In addition to his role in helping to facilitate the vaccination of his local community, Dr Hughes is emphatic about helping to end the pandemic through improved ventilation. He wants policy-makers to consider ventilation as an easy win that could help mitigate future virus outbreaks.
“What is the size of the room, how much ventilation, number of people, how long do you spend in that room?” Dr Hughes explains. “How many pairs of lungs are there in that room? We need to act now.”
Dr Nishant Joshi is a frontline medical doctor working in the NHS