British ear, nose and throat doctors have called on adults who lose their sense of smell to isolate themselves for seven days, even if they have no other symptoms, as studies indicate that a loss of smell and taste could be a symptom of COVID-19, the disease caused by the novel coronavirus.
“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,” said Prof. Claire Hopkins, president of the British Rhinological Society, according to the New York Times. “It could contribute to slowing transmission and save lives.”
Ear, nose and throat specialists and eye doctors were infected and dying in large numbers in earlier reports from Wuhan, China, the epicenter of the coronavirus outbreak, according to Hopkins.
Reports from multiple countries have indicated that significant numbers of coronavirus patients experienced anosmia, the loss of sense of smell, and ageusia, an accompanying diminished sense of taste, according to the Times.
The American Academy of Otolaryngology stated on Sunday that mounting anecdotal evidence indicates that lost or reduced sense of smell and taste are significant symptoms related to COVID-19. Some coronavirus patients have had these symptoms without any others.
"There is evolving evidence that otolaryngologists [head and neck surgeons] are among the highest risk group when performing upper airway surgeries and examinations,” said a notice on the academy’s website on Friday. “A high rate of transmission of COVID-19 to otolaryngologists has been reported from China, Italy and Iran, many resulting in death.”
In Italy, doctors have concluded that loss of taste and smell is an indication that a person who may otherwise seem healthy is actually carrying and spreading the virus.
According to Dr. Clemens Wendtner, a professor of medicine at the Academic Teaching Hospital of Ludwig-Maximilians University of Munich, patients regained their ability to smell after a few days or a week. The loss occurred regardless of how sick they got or whether they were congested. Nasal drops or sprays did not help.
Studies on the newly realized symptoms have not been done, as physicians handling the coronavirus outbreak are overwhelmed, according to Forbes.
German virologist Hendrik Streek took daily samples from infected workers isolated in a hospital and interviewed them about the progression of their symptoms. He found that two-thirds of those he interviewed described "a loss of smell and taste lasting several days," according to Forbes.
Both Streek and Massimo Galli, Professor of Infectious Diseases at the University of Milan, found that the loss of smell and taste usually occurred late in the course of infection.
According to Judy Stone, an infectious disease specialist, the only other infection they knew of with a loss of smell was Herpes simplex encephalitis, a rare neurological disorder characterized by inflammation of the brain, according to the National Organization for Rare Disorders.
Medical professionals are unsure what is causing the loss of the senses of smell and taste. Some viruses destroy the cells or cell receptors in your nose, while others infect the brain via the olfactory sensory nerves. The ability to infect the brain may explain some of the cases of respiratory failure in COVID-19 infections; evidence shows that coronaviruses may invade the central nervous system.
SARS has been reported in the brains of both patients and experimental animals and, considering the high similarity between the 2012 SARS virus and the novel coronavirus (officially called SARS-CoV-2), an infection of the nervous system may be partially responsible for the respiratory failure of patients with COVID-19, according to a study by Yan‐Chao Li, Wan‐Zhu Bai and Tsutomu Hashikawa that was published in the Journal of Medical Virology last month.
Deputy chairman of Iran’s Rhinology Association Dr. Ebrahim Razmpa told the Iranian ISNA news agency that there has been "a sudden, unexpected and unbelievable jump in cases of weak sense of smell and difficulty with vision" since the coronavirus outbreak reached the Islamic Republic, although it is still unclear whether the coronavirus or other factors caused the spike, according to Radio Farda.
As of Monday morning, almost 350,000 cases of the novel coronavirus had been confirmed around the world, with just over 15,000 dead and 100,000 reports of recoveries.