Lost Sense Of Smell May Be A Clue To Infection

The loss of smell and accompanying diminished sense of taste appear to be emerging as possible signs of COVID-19 and may be a marker of infection as British ear, nose and throat doctors have been citing reports from global colleague who are also recommending those with anosmia and ageusia to isolate themselves for at least 7 days to see if any other symptoms develop in attempts to slow spread of the disease. Although the published data is limited the group of doctors are still concerned enough about it to raise the warning of possibility. 

“We really want to raise awareness that this is a sign of infection and that anyone who develops loss of sense of smell should self-isolate,” Prof. Claire Hopkins, president of the British Rhinological Society wrote. “It could contribute to slowing transmission and save lives.”

Along with Nirmal Kumar, president of ENT UK which is a group representing ear, nose, and throat doctors in Britain, Hopkins issued a joint statement in which they urge healthcare workers to use PPE when treating any patients who have lost the sense of smell. They also are advising against performing any nonessential sinus endoscopy procedures because the virus replicates in the nose and throat, meaning any exam could prompt coughs and/or sneezing that can expose doctors to a high level of the virus should the patient be infected. 

The British physicians are citing reports from countries suggesting that a significant number of infected patients were experiencing anosmia and that in South Korea where there has been widespread testing 30% of 2000 patients who tested positive for mild cases in a study also experienced anosmia as their major presenting symptom. 

Additionally the American Academy of Otolaryngology has also suggested that mounting anecdotal evidence indicates that lost or reduced sense of smell and loss of taste are significant symptoms associated with COVID-19 infection, and that it has been seen in patients that have tested positive with no other symptoms. 

These symptoms in the absence of allergies or sinusitis should alert doctors to screen for the virus and “warrant serious consideration for self isolation and testing of these individuals,” according to the organization who remind their members that the CDC is urging all clinicians to prioritize urgent and emergency visits for the next several weeks and to reschedule any elective and routine procedures. 

In the areas most heavily affected by the virus in Italy doctors are also concluding that the loss of taste and smell is an indication that an otherwise healthy person is in fact carrying the virus and may be spreading it to others. 

“Almost everybody who is hospitalized has this same story,” said Dr. Marco Metra, chief of the cardiology department at the main hospital in Brescia. “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 with a very mild form.”

German virologist Hendrik Streeck from the University of Bonn has conducted interviews with patients, and in these interviews he reports that at least two thirds of the 100 with mild cases were experiencing loss of smell and taste lasting for several days. 

Another cluster of patients in Germany also report experiencing a smell or taste disorder which presented after first symptoms of respiratory illness; according to Dr. Clemens Wendtner from the Academic Teaching Hospital of Ludwig Maximilians University of Munich the patients regained their abilities after a few days-weeks, and this loss occurred regardless of how sick they became or how congested they were and that nasal drops/sprays did not help.

In America several suspected infected patients have reported similar symptoms, but they have not been tested and/or are still awaiting their test results; their similar reports describe losing their sense of smell and taste even though their noses were clear and they were not congested.