Australia’s Chief Medical Officer Professor Brendan Murphy said last week that worldwide cases of COVID-19 could be “five to 10 times” higher than what is currently being reported.
That’s due to a myriad of reasons, including a shortage of testing in most countries. But it also could be due to a high number of people who have contracted COVID-19 without even knowing it.
Not only does that mean many people could have already been infected with the virus without being diagnosed, but it also means many people could have COVID-19 right now, without realising.
So, what proportion of those with coronavirus are symptom-free? And can they transmit the disease to other people?
Here’s exactly what we know.
Firstly, what does asymptomatic actually mean?
The World Health Organisation defines an asymptomatic case as a person infected with COVID-19 who does not develop symptoms.
Watch: Mamamia breaks down your most common questions about COVID-19. Post continues below.
What proportion of those with COVID-19 are asymptomatic?
This is unclear. Mostly because testing those who are asymptomatic are, for obvious reasons, not being tested nearly as much as people who are displaying symptoms.
However, there is research to give us a fairly good understanding of the proportion of people with COVID-19 who are asymptomatic.
Of the 3,711 passengers and crew members on board, a total of 634 passengers tested positive to COVID-19.
Of those who tested positive, researchers estimate 17.9 per cent were asymptomatic. That’s nearly one in five cases which are asymptomatic.