Why wearing a mask might not prevent the spread of coronavirus

What is a coronavirus?

Coronavirus is the scientific name for a group of viruses that cause things like common colds and more serious illnesses like SARS (severe acute respiratory symptom). They can be transmitted from humans to other humans or from animals to humans.

Why is it in the news today?

The coronavirus we’ve been hearing about is a new strain of the virus that nobody had come across before it struck patients in Wuhan, Hubei Province, China last year. It has now been named COVID-19 (Corona Virus Disease 2019), and is classified as a respiratory illness caused by virus strain SARS-COV-2 (severe acute respiratory syndrome coronavirus 2 and as of yet, there is no vaccine.

It is currently a serious issue because of the rate at which it is spreading and the fact that it can be fatal.

As of writing there has been 1,923,651 reported cases and over 119,595 deaths globally (you can keep up to date with the current figures here).

How is it transmited?

During the initial stages of the outbreak, it was thought that there was animal-to-person spread originating in a seafood and live animal market. However, a lot of patients didn’t have any contact or exposure with animal markets suggesting that there is in fact person-to-person spread.

This has been the case in countries all across the world where it appears to be spreading easily due to a lack of social distancing, limited testing and poor hygiene practices when the first few cases began to appear. This led to a high level of person to person spread first in Italy, which became the new epicentre of the virus, and then the rest of Europe before the number of cases grew in the United States.

Person to person spread comes about when people come within six feet of an infected patient. It is thought that people are most contagious when they’re sick. The virus is spread through droplets produced by sneezing and coughing.

Although, currently the World Health Organisation doesn’t believe that COVID-19 is airborne, a research article in Environmental International states:

National authorities [should] acknowledge the reality that the virus spreads through air, and recommend that adequate control measures be implemented to prevent further spread of the SARS-CoV-2 virus.

Will wearing a mask prevent transmission?

Much has been made of members of the public wearing face masks with the WHO reluctant to state that it’s a foolproof method of preventing transmission. While local authorities are suggesting that people wear cloth face masks while out and about, there is not yet enough evidence to say that they will stop people from catching COVID-19.

The question has remained: are masks effective when it comes to preventing droplets from spreading?

In short, no.

That’s the worrying answer a group of researchers in South Korea arrived at when they put surgical masks and cotton masks to the test.

They found that neither type of mask was effective in stopping the spread of SARS-CoV-2 (the virus strain that’s responsible for COVID-19).

What the researchers did was take four patients who are currently infected with COVID-19 and asked them to cough up to 5 times over petri dishes in different settings –

without a mask
with the cotton mask
with the surgical mask.

Using swabs, the researchers determined if there were traces of COVID-19 on both the inner and outer surfaces of the mask. While they were expecting to find traces on the inner surfaces, the real test was whether or not the droplets containing the virus had travelled to the outer surface of each mask.

Unfortunately, they found that droplets had in fact passed through the mask and were present on the outer surface. This means that neither mask was good at filtering SAR-Cov-2 when each patient coughed.

It is not yet known how large particles containing SAR-CoV-2 are, but if they’re similar to SAR-CoV-1, it would suggest that mask would be inadequate.

Quite alarmingly, the outer surface of the masks were more contaminated than the inside. While researchers note that this might be due to air leaking from the side of the masks, it would pose a huge health risk if wearers were not maintaining good hand hygiene while removing the masks.

The South Korean researchers also state that it is unclear if masks can shorten the distance that droplets can travel during a cough.

Furthermore, additional research is needed to test the effectiveness of masks on patients who are not coughing or showing symptoms.