Smell, taste and COVID-19: testing is essential.

Area of Science:

• Neurology
• Infectious Diseases
• Otolaryngology

Background:

• Chemosensory disturbances, including smell and taste loss, are common early symptoms of COVID-19.
• The specific mechanisms and prevalence of these sensory impairments require further investigation.

Purpose of the Study:

• To investigate the mechanisms behind COVID-19's impact on smell and taste.
• To determine the frequency of chemosensory loss in COVID-19 patients.
• To assess the prognosis of smell and taste dysfunction and explore screening applications.

Main Methods:

• Review of existing literature and clinical observations regarding COVID-19 and chemosensory function.
• Analysis of symptom-based questionnaires and formal olfactory testing data.
• Discussion of potential screening strategies using olfactory tests.

Main Results:

• COVID-19 specifically targets olfactory and potentially gustatory pathways.
• Symptom-based assessments may underestimate chemosensory impairment prevalence by up to 50%.
• High prevalence of smell loss suggests olfactory testing can be a reliable indicator of infection.

Conclusions:

• Formal olfactory testing is a sensitive method for detecting COVID-19 infection.
• Individuals with impaired olfaction, even without other symptoms, may transmit the virus.
• Low-cost olfactory tests offer a viable, high-throughput screening tool for early COVID-19 detection.