The Science

Loss of Sense of Smell and COVID-19

Studies from institutions including Mayo Clinic and Harvard Medical School indicate that full (anosmia) or partial (hyposmia) loss of sense of smell, or Olfactory Dysfunction (OD), can be one of the first symptoms experienced by someone who has contracted COVID-19. 

In an article published by Harvard Medical School, researchers state that “temporary loss of smell, or anosmia, is the main neurological symptom and one of the earliest and most commonly reported indicators of COVID-19. Studies suggest it better predicts the disease than other well-known symptoms such as fever and cough…”¹

In an article published by the National Institutes of Health, researchers at the Mayo Clinic found that OD is “… one of the earliest signatures of COVID-19.”²

Many times, the individual is not even aware their sense of smell has become impaired. Therefore, simply questioning a person may not provide useful information. In a study conducted by Moein et al, of subjects who tested positive for OD, only 35% of them were aware of their condition prior to being tested.³

Diminished sense of smell is not present in all COVID-19 cases. However, it is frequent enough that it can be used as an early indicator that a person should isolate and obtain a definitive test for COVID-19.

Problems with Temperature Screening

Many organizations are using temperature screening as a method to determine if a person is potentially infected with COVID-19. However, medical professionals have stated that checking for fever is not a reliable method to screen out infected individuals. 

Forbes reported, “Dr. Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said Thursday that temperature checks are unreliable for detecting coronavirus symptoms in people entering businesses and other establishments…”⁴ The World Health Organization stated that “temperature screening alone, at exit or entry, is not an effective way to stop international spread…”⁵

Benefits of Testing Sense of Smell

Screening for diminished sense of smell can augment screening procedures and help prevent the spread of infection. It is non-invasive, inexpensive, and rapid. While screening for OD is not a perfect indicator of infection and must not replace PCR COVID-19 testing, it is an additional tool that can be used to safeguard organizations and their people.