Viral Infections of the Upper Airway in the Setting of COVID-19: A Primer for Rhinologists

Background: Viral respiratory tract infections are associated with a significant burden of disease and represent one of the leading causes of mortality worldwide. The current Coronavirus Disease 2019 (COVID-19) pandemic highlights the devastating toll that respiratory viruses have on humanity and the desperate need to understand the biological characteristics that define them in order to develop efficacious treatments and vaccines. To date, Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has infected nearly 600 times more people and resulted in 200 times more deaths relative to Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV) and Middle Eastern Respiratory Syndrome Coronavirus (MERS-CoV) combined. Objective: Through this review, we aim to summarize the key characteristics of respiratory viruses that hold global significance, with a focus on SARS-CoV-2. Our goal is to disseminate our current knowledge of these infectious agents to otolaryngologists, in particular rhinologists, practicing in the COVID-19 era. Methods: The general and clinical characteristics of selected respiratory viruses along with available viral treatments and vaccines are reviewed. Results: There has been significant progress in our understanding of the epidemiology and pathogenesis of various respiratory viruses. However, despite the advancement in knowledge, efficacious vaccines and antiviral treatments remain elusive for most respiratory viruses. The dire need for these scientific discoveries is highlighted by the recent COVID-19 pandemic, which has prompted investigators worldwide to conduct clinical trials at an accelerated timeline in an effort to reduce the morbidity and mortality associated with SARS-CoV-2 infection. Rhinologists will continue to remain on the front-lines of pandemics associated with respiratory viruses. Conclusion: In light of these unprecedented times, the need to understand the nuances of these viral respiratory pathogens, especially SARS-CoV-2, cannot be overemphasized. This knowledge base is of particular importance to otolaryngologists, whose expertise in the upper airway coincides with the anatomic tropism of these infectious agents.