Health experts say up to 40% coronavirus cases are caused by asymptomatic carriers as they urged people to wear masks to stop the spread of the disease.
In a briefing today, the World Health Organisation [WHO] said it was "absolutely convinced" that asymptomatic cases were occurring despite having limited data.
According to their analysis, somewhere between 14% to 40% of cases were caused by symptom-less carriers. In addition, studies show people with the coronavirus are most infectious when they first show symptoms.
The Geneva-based organisation also said wearing masks could help stop the spread of the disease by "asymptomatic" or presymptomatic" carriers.