Could nearly half of those with Covid-19 have no idea they are infected?
As studies confirm many infected people show no symptoms, contact tracing and face masks assume even greater importance
When Noopur Raje’s husband fell critically ill with Covid-19 in mid-March, she did not suspect that she too was infected with the virus.
Raje, an oncologist at Massachusetts General Hospital in Boston, had been caring for her sick husband for a week before driving him to an emergency centre with a persistently high fever. But after she herself had a diagnostic PCR test – which looks for traces of the Sars-CoV-2 virus DNA in saliva – she was astounded to find that the result was positive.