Published on May 15, 2023

Authored by Dr Cassy Richmond

What causes COVID-19 illness?

Coronaviruses are a large family of viruses that may cause a range of respiratory illnesses in humans, including the common cold, Middle East Respiratory Syndrome (MERS-CoV), and Severe Acute Respiratory Syndrome (SARS-CoV).¹ The coronavirus strain involved in the ongoing pandemic has been named SARS-CoV-2 by the World Health Organization (WHO). The disease it causes is called “coronavirus disease 2019” (or “COVID-19”).^2,3

How Does The COVID-19 Virus Spread?

COVID-19 can spread from person to person:^4,5

• Through close contact with someone who is infected

• Via contact with droplets that are spread into the air when an infected person coughs, sneezes, talks or sings

• Touching objects or surfaces (e.g. door knobs) that have droplets from an infected person, and then touching your mouth or face

• Spread is more likely when people are gathered in close proximity to each other.⁶

Since the beginning of the pandemic in 2020, we have seen that COVID-19 is infectious. Because it spreads so easily, it has infected whole communities and populations around the world. It’s high rate of infectivity has made some strains particularly difficult to control.

What Are The Symptoms of COVID-19?

People with COVID-19 may have symptoms that range from mild to severe. Some people with COVID-19 experience no symptoms at all. For those who develop symptoms, these may include:⁵

• Fever or chills

• Cough

• Shortness of breath or difficulty breathing

• Fatigue

• Muscle or body aches

• Headache

• Loss of taste or smell

• Sore throat

• Congestion or runny nose

• Nausea or vomiting

• Diarrhoea

If you think you might have COVID-19, or have been exposed to anyone who has COVID-19, you should get tested, either with a PCR test or rapid antigen test (RAT), and notify your local doctor.

If you have underlying health conditions, you may be at risk of becoming really unwell with COVID-19. To find out if you may be at risk of developing severe COVID-19, click here.

It’s also good to know that, if you are at risk of becoming really unwell you may be eligible for COVID-19 treatment. Click here to find out more.

People with COVID-19 can become unwell quickly. Always remember: if you have concerns about your health at any time, seek medical attention immediately.

References

1. Coronavirus. World Health Organization. https://www.who.int/westernpacific/health-topics/detail/coronavirus. Accessed 9 May 2023.

2. Q&A on Coronavirus disease (COVID-19). World Health Organization. https://www.who.int/emergencies/diseases/novel-coronavirus-2019/question-and-answers-hub/q-a-detail/coronavirus-disease-covid-19. Accessed 9 May 2023.

3. WHO Director-General's remarks at the media briefing on 2019-nCoV on 11 February 2020. World Health Organization. https://www.who.int/director-general/speeches/detail/who-director-general-s-remarks-at-the-media-briefing-on-2019-ncov-on-11-february-2020. Accessed 9 May 2023.

4. How COVID-19 Spreads. Centers for Disease Control and Prevention. https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/how-covid-spreads.html. Accessed 9 May 2023.

5. COVID-19 disease, symptoms and variants. Australian Government. https://www.health.gov.au/news/health-alerts/novel-coronavirus-2019-ncov-health-alert/ongoing-support-during-coronavirus-covid-19/what-you-need-to-know-about-coronavirus-covid-19. Accessed 9 May 2023.

6. Protect yourself and others from COVID-19. Australian Government. https://www.health.gov.au/health-alerts/covid-19/protect-yourself-and-others. Accessed 9 May 2023.

External Resources

- World Health Organisation: Coronavirus disease (COVID-19)
- Australian Government Department of Health: COVID-19 disease, symptoms and variants