What is COVID-19 and what does 'flatten the curve' mean?

In today’s post, Dr Kathryn Snow methodically and clearly addresses some key questions about COVID-19. Dr Snow is a health services researcher and epidemiologist at the University of Melbourne and the Murdoch Children’s Research Institute, and collaborates with clinicians, health authorities, and qualitative researchers to improve health services for vulnerable groups. This article was originally published on her blog.

Author’s note: This blog has been written on the 13th of March 2020. The situation is changing rapidly and some of the information below may be out of date in the coming weeks or months.

What’s COVID-19?

The new coronavirus (now being called COVID-19 or SARS-CoV-2) is a new virus related to some colds, and to SARS. It causes a cough and fever, and in more serious cases, difficulty breathing. The illness is almost always mild in younger people, but older people are more likely to get seriously ill, or to die.

COVID-19 is quite infectious. Because it’s a new virus, we don’t have any natural immunity yet. We also don’t have a vaccine.

The virus has spread very quickly in China, South Korea, Iran, and Italy. Other countries are also likely to see large outbreaks. That’s why preventive measures are currently being taken in many countries including closing schools, entire businesses cancelling travel and encouraging employees to work from home, and so on.

In some countries like Singapore and Hong Kong, these measures have kept the outbreak under control. Other countries will be trying to replicate that.

What’s happening right now? What does a pandemic mean for all of us?

Right now, the outbreak is being controlled in China, Hong Kong and Singapore. It is very intense in Italy, and it is gaining speed in other places. Because the virus is now spreading in multiple countries in different regions (Asia, the Middle East, and Europe), the World Health Organisation has declared it a pandemic.

The health system in parts of northern Italy has been overwhelmed. So many people got seriously ill at once that they don’t have enough intensive care unit beds or equipment to care for everybody. This is a horrible situation.

Everybody watching wants to avoid that happening in their own country or region. That is why many governments are sending out messages about washing your hands and staying at home when you’re sick. Because we don’t have a vaccine yet, these measures are the most effective things we can do to protect ourselves and each other.

Am I personally at risk? What should I do?

All of us will be at risk of catching the virus, but our risk of getting seriously ill is very different.

If you are under 50, your personal risk of getting seriously ill or dying is very, very low, even if you have other health problems. Children can catch the virus, but almost none of them seem to be getting seriously ill or dying.

In people over 50, the risk of serious illness or death rises with age and with pre-existing medical conditions like diabetes (especially if glucose is not within the target range), lung disease like asthma or emphysema, or heart disease. In China, around 15% of people in their 80s have died after getting the virus. In the United States, where the virus is known to be spreading in the community, the CDC is encouraging older people to stay home as much as possible.

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Those of us who are young and healthy can help to protect those who are older and more vulnerable. Everybody has a role to play – by reducing our own risk of infection, we are also helping to protect other people. By reducing how much time we all spend on planes or in shared offices, we can limit the chances for the virus to spread.

This is similar to the concept of ‘herd immunity’ for vaccination – we are trying to starve the virus of opportunities to jump from one person to the next. If we can do this, we can reduce the chance that older, more vulnerable people will get the virus. If we all wash our hands more often, every handshake becomes lower risk. Better yet, go for a toe-tap instead! Not everybody can work from home or limit their travel, so those of us who can, should. We are all in this together, and we all need to do what we can.

What’s going to happen next?

Public health professionals are worried about health systems being overwhelmed. Many aspects of this virus will stress different parts of the system, especially GP/primary care clinics, emergency rooms, and intensive care units. By slowing the spread of the virus, we can limit the number of people who need to see a doctor or be in hospital at any one time. Instead of trying to take care of 10,000 people in one week, your local emergency room could care for 1,000 people every week for 10 weeks. 

This is what public health professionals mean when we talk about ‘flattening the curve’. At the peak of this
epidemic, our health system could be under severe pressure. Huge numbers of people could be going to their GPs, the emergency room, and being admitted to intensive care units. This would affect everybody – women giving birth, people with cancer, anybody who has a car accident or a heart attack.

The more we can slow down the spread of the virus, the lower this peak demand will be – like turning off your
air conditioning on a hot day to spare the electricity grid. As the virus spreads in your area, your government might take steps like cancelling large events, closing schools, and asking people to stay at home except for essential activities. Please listen to their advice and follow their instructions. Be wary of misinformation circulating on social media.

These types of measures are hugely disruptive and expensive. But this is a very serious situation, and this is what we need to do to slow the virus down. If we do that, we can protect ourselves, each other, and our health system until we have a vaccine.

Content moderator: Sue Olney