Source: New York Times

Doctor groups are recommending testing and isolation for people who lose their ability to smell and taste, even if they have no other symptoms.
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Anosmia, the loss of sense of smell, and ageusia, an accompanying diminished sense of taste, have emerged as peculiar telltale signs of Covid-19, the disease caused by the coronavirus, and possible markers of infection.

On Friday, British ear, nose and throat doctors, citing reports from colleagues around the world, called on adults who lose their senses of smell to isolate themselves for seven days, even if they have no other symptoms, to slow the disease’s spread. The published data is limited, but doctors are concerned enough to raise warnings.
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“Almost everybody who is hospitalized has this same story,” said Dr. Marco Metra, chief of the cardiology department at the main hospital in Brescia, where 700 of 1,200 inpatients have the coronavirus. “You ask about the patient’s wife or husband. And the patient says, ‘My wife has just lost her smell and taste but otherwise she is well.’ So she is likely infected, and she is spreading it"

Read more: https://www.nytimes.com/2020/03/22/health/coronavirus-symptoms-smell-taste.html