Trending Clinical Topic: Airborne Coronavirus

Ryan Syrek


July 24, 2020

Each week, we identify one top search term, speculate about what caused its popularity, and provide an infographic on a related condition. If you have thoughts about what's trending and why, share them with us on Twitter or Facebook. Find the latest COVID-19 news and guidance in Medscape's Coronavirus Resource Center.

For several months, concerns have been raised about the potential of SARS-CoV-2 spreading via airborne transmission. As cases surge in the United States and elsewhere, this method of contagion is now drawing increased scrutiny, making it this week's top trending clinical topic.

In late May, Kimberly Prather, PhD, was already sharing her alarm at the failure of the Centers for Disease Control and Prevention (CDC) and World Health Organization (WHO) to suggest that SARS-CoV-2 could be passed through the air. In an article published in Science , Prather laid out the evidence for aerosol transmission. Airborne transmission, she contends, would mean that standing 6 feet apart is not far enough and also reinforces the value of wearing masks.

Concerns about airborne spread have only intensified, leading hundreds of scientists across 32 countries to pen a letter to the WHO, outlining the evidence and asking the organization to revise its recommendations regarding transmission. WHO's delay in updating its guidance was widely criticized. However, on July 9, the group changed language in its precautions, stating, "Short-range aerosol transmission, particularly in specific indoor locations, such as crowded and inadequately ventilated spaces over a prolonged period of time with infected persons, cannot be ruled out."

The role that air conditioning may play in the airborne transmission of coronavirus is also under investigation. HVAC systems recirculate air, especially when it is hot outside. When outdoor temperatures are extreme, indoor air recirculates more, leading people inside to breathe a higher percentage of the same air that is exhaled. Also, the fan component of air conditioners can give coronavirus aerosols extra lift to stay suspended in the air longer.

With an eye toward protecting healthcare workers from airborne transmission of coronavirus during intubation, clear aerosol boxes are being used in some healthcare institutions. However, a small study suggests that this approach may actually increase providers' exposure. The so-called "intubation boxes" concentrate the virus inside; when a patient coughs, a sudden wave of air pushes the concentrated aerosols through the gaps that allow the provider to reach in. Some barriers may be more effective than others, and the hope is that further research will identify designs that provide meaningful protection to healthcare workers.

As the school year approaches in many regions, targeting effective prevention strategies is  more important than ever. Addressing the potential for airborne transmission is a major focus, meaning that this week's top trending clinical topic is likely to stay popular for quite some time.

Read more clinical information about COVID-19.


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