explainer

Viral droplets and contaminated surfaces: What you need to know about how COVID-19 is transmitted.

In Australia, there have been 33 cases of COVID-19, also known as Novel coronavirus. And this week, three of those were confirmed to be cases of human-to-human transmission.

In simple terms, that means the patients had not travelled overseas to one of COVID-19’s known hotspots, and therefore likely contracted it from someone in Australia who had.

It’s a common pattern emerging around the world.

Should I stockpile? Your top 20 coronavirus questions answered. Post continues after podcast. 

Since the disease was first reported in China’s Hubei Province in late December 2019, it’s been detected in a further 73 countries. South Korea, Iran and Italy, for example, have emerged as international hotspots with 9,184 cases between them.

In fact, the virus is now spreading at a faster rate outside China than it is within. In the 24 hours to Tuesday, China reported just 129 new cases: its lowest number since January 20.

This is good news. It’s evidence that the spread of COVID-19 can be slowed and eventually contained with the right response.

And here, that starts with you.

So let’s take a look at what scientists understand about how COVID-19 spreads among the community, and what you can do to help prevent it.

How COVID-19 spreads.

COVID-19 is transmitted via small droplets of fluid from the nose and mouth of someone who is sick.

As the World Health Organisation said on Tuesday, despite the comparisons to the flu, COVID-19 actually spreads far less efficiently.

While influenza sufferers can transmit the virus before they become ill, evidence from China indicates that only 1 per cent of reported COVID-19 cases don’t have symptoms. And most of those cases develop symptoms within two days.

These are the main ways a sick person’s viral droplets will spread.

Coughing, sneezing, breathing.

COVID-19 can be spread by a sick person coughing or sneezing in the presence of others.

How to prevent infection: The World Health Organisation advises people to remain at least one metre away from anyone who is coughing or sneezing to avoid breathing in viral droplets.

Some people are using medical face masks for this purpose, however, the WHO has stressed that there is “no evidence that they protect people who are not sick”. Especially when used without other strict preventative measures.

Dr Sanjaya Senanayake, Associate Professor of Medicine and Infectious Diseases Physician at the Australian National University, reiterated this point when speaking to Mamamia‘s daily news podcast, The Quicky.

“There are two situations where a mask will help,” he said. “In the hospital setting, if you’re a healthcare worker seeing a person with COVID-19 and you’re wearing your personal protective equipment; And if we’re having a wider outbreak in Australia and you’re looking after someone at home with Novel coronavirus, then wearing a mask will help. But generally wearing it in the wider community when you’re going outside won’t be that helpful.”

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That’s partly because it’s more common that viral droplets will spread by a sick person coughing or sneezing and creating…

Contaminated surfaces.

When our hands touch surfaces, they pick up microbes, including viruses. When we then touch our contaminated hands to our eyes, nose or mouth, those microbes can infect the body.

There is evidence of this happening with COVID-19.

After a cluster of six people were diagnosed after visiting a temple in Hong Kong in late January and early February, government authorities swabbed the site and found the virus was present on bathroom faucets and on the cloth covers used for scriptures.

How to prevent infection: Hand hygiene is crucial to preventing the spread of COVID-19. The WHO advises using alcohol-based hand sanitiser and washing your hands regularly.

Ordinary soap is perfectly effective as long as you lather thoroughly for at least 20-30 seconds (roughly the time it takes to sing ‘Happy Birthday’ twice), scrub every nook and cranny, and rinse with running water.

What about…

Kissing: Yes. Kissing a person with COVID-19 could result in infection. Avoid having a pash with anyone with cold or flu-like symptoms (good advice regardless of a COVID-19 outbreak).

Sex: Other coronaviruses are not sexually transmitted, and there is currently no evidence that COVID-19 is either.

Air conditioning: There is no evidence that COVID-19 is an airborne virus. i.e. it doesn’t remain floating around a room after an infected person leaves it.

Who is most likely to catch COVID-19?

Anyone can. It’s called ‘Novel’ coronavirus because it’s new, and therefore no one has immunity. But that’s not actually cause for panic.

While COVID-19 has spread widely, the vast majority of cases (more than 81 per cent, according to a recent Chinese study) are mild. The pertinent question is, instead, who is most likely to become seriously ill?

Ass Prof Senanayake told Mamamia, “In terms of those people who are most likely to get really sick from it, it looks like it’s people over the age of 60 and people who have more [underlying] health issues, such as high blood pressure, obesity, diabetes.”

So while you may not be at risk of serious illness, consider those members of our community who may be. With proper hygiene and proper strategies from our health authorities, this can — and will — be effectively contained.

Keep calm, wash your hands and carry on.

Feature image: Getty.

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