What does it all mean?

COVID-19: A type of coronavirus first reported last December in China which by the end of last month had infected more than 750,000 people in 176 countries and killed more than 36,000, including 17 in Australia.

There is no specific treatment for Covid-19 and scientists in several countries are working to develop a vaccine.

Most people recover on their own but can spread the virus to others while infected.

Coronavirus: Part of a group of related viruses that include Covid-19.

Severe Acute Respiratory Syndrome (SARS): A coronavirus first reported in China in 2002 that infected more than 8000 people in 29 countries (six in Australia) and killed 774 worldwide (none in Australia).

Middle East Respiratory Syndrome (MERS or Camel Flu): A coronavirus first reported in Saudi Arabia in 2012 that infected more than 2500 people in 26 countries and killed more than 500 people (none in Australia).

Virus: A small infectious agent that replicates only inside the living cells of an organism.

Influenza (flu): An infectious disease caused by a virus that spreads by coughing and sneezing or touching contaminated surfaces and then touching the eyes, nose, or mouth.

The 1918 Spanish Flu killed up to 100 million people worldwide, including 15,000 in Australia.

New vaccines are constantly being developed to counter influenza virus mutations.

Cold: A viral disease of the upper respiratory tract that mainly affects the nose.

Colds have similar but less severe symptoms to influenza and are more likely to include a runny nose. There is no vaccine to prevent the common cold.