The science of washing hands and wearing face mask

Covid-19 Fact vs Myths Part 2

KUCHING: Imagine someone sitting next to you, is sneezing or coughing.

First alert, are you wearing a mask? Checked! Oh relief!

But what if you are unprotected?

According to epidemiologist Datuk Dr Andrew Kiyu Dawie Usop, if a person is positive Covid-19, the droplets in a single cough or sneeze may produce as many as 200 million of virus particles.

“When somebody call us and we are unprotected, just imagine with just one sneeze or one cough is enough to cause an infection.

“Thirty thousand droplets from a single sneeze can travel up to 200 miles per hour. From a single cough, 3,000 droplets that are released are able to travel at 50 miles per hour.

“Whereas if you’re sitting with somebody who is breathing quietly and not talking, it would take 30 minutes for a person to get infected,” he said when speaking at the Health Talk Series programme entitled ‘Covid-19: Facts vs Myths’ streamed live over Unimas Facebook recently.

Depending on three factors — the distance, type of activity and the capacity of environment, Dr Kiyu said that a person in a crowded place, in a confined space and in a close-contact setting (3Cs) is highly prone to get the infection.

He said such condition would allow the virus to spread easily.

“A successful infection depends on how the person is exposed to the virus and the length of the time period of exposure.

“According to a study done by Erin Bromage, an infection could occur through 10 viral particles with just 100 breaths.

“Or from just one eye-rub, you can receive 1,000 infectious viral particles!

“For example, by singing at a karaoke centre or talking at the bar, five minutes are enough for a successful infection.

“Of course, at the karaoke centres, you will not use mask to sing loudly. You are not able to practise social distancing once you’re in that kind of environment,” he explained.

Face mask efficacy

There is no doubt that everyone now is wearing face mask.

But hold on. Does it really protect you from those droplets?

The global shortage — of commercial face mask supplies has led to the widespread use of homemade masks and other alternative ones which assumes that wearing such masks reduces the likelihood for an infection.

In fact, it has turned into a fashion trend, which is lucrative.

The truth is, many of these mask designs have not been tested in practice, said Dr Andrew Kiyu.

“There are characteristics of SARS-Cov2 that make us possible to prevent its transmission.

“The virus is very small — even the size of a single human hair can contain as many as 400 SARS CoV2 particles, to as many as 1,000 particles.

“Even the respiratory droplets contain a lot of viral particles. But we are very lucky because even though they are very small, these virus particles are able to be controlled on its transmission through face mask.

“For instance, the three-ply surgical mask, the cotton-polypropylene-cotton mask and the N95 mask.

“For ordinary use it’s better to use the three-ply surgical mask, and then some of the cotton mask.

“Some of the other masks are not very effective. For example, using bandana or neck gaiter as face mask,” he added.

Although face masks today are affordable and easy to access, Dr Kiyu reiterated that using a correct type of face mask is important to reduce the speed of the droplets from the outside surface.

“When somebody sneezes or coughs, the droplets in the air could last for three hours.

“The safer place is a place where the environment is having natural ventilation, compared to a place with closed ventilation,” he stressed.

Wash hands with soap

Another important practice to prevent the transmission of the Covid-19 virus is washing hands with soap, Dr Kiyu pointed out.

He explained the mechanism through washing hand with soap was the most effective one to break the virus.

“The other thing is that even the virus wants to get into our body system, the virus needs to attach themselves.

“And they (virus) are vulnerable too, in the sense that their lipids can be broken by soap. and once the code is broken, then they (virus) become disabled, disrupted and no longer able to do its infectious job,” he said.

He also advised to practise the utmost personal hygiene to reduce the risk of infection.

“All you need to do is to wash hands properly for 20 seconds. This will be long enough to kill the virus.

“There are other ways too, to destroy the virus apart from soap, for example using alcohol sanitiser and nitric oxide,” he added.