A recent study, published in the British Medical Journal, suggested that 78% of people with COVID-19 have no symptoms.
The findings are in line with research from an Italian village at the epicentre of the outbreak showing that 50%-75% were asymptomatic, but represented "a formidable source" of contagion.
A recent Icelandic study also showed that around 50% of those who tested positive to COVID-19 in a large-scale testing exercise were asymptomatic.
Meanwhile, a WHO report found that "80% of infections are mild or asymptomatic, 15% are severe infections and 5% are critical infections." Though we don't know what proportion of that 80% were purely asymptomatic, or exactly how the cases were counted, it again points to a large majority of cases who are not going into hospital and being tested. End quote
