COVID-19 Transmitted Through Aerosols: The Evidence Supporting the Claim

Posted by Frank Holman on 9/28/20

The belief that COVID-19 spreads through aerosols has its skeptics, including World Health Organization advisors, but now new research is adding to the assumption that many feared all along—that COVID-19 spreads through the air.

According to The New York Times, “A research team at the University of Florida succeeded in isolating live virus from aerosols collected at a distance of seven to 16 feet from patients hospitalized with COVID-19 — farther than the six feet recommended in social distancing guidelines.” 

The author notes; however, that these findings have not yet been peer reviewed.

“In the new study, researchers devised a sampler that uses pure water vapor to enlarge the aerosols enough that they can be collected easily from the air,” according to the article. “Rather than leave these aerosols sitting, the equipment immediately transfers them into a liquid rich with salts, sugar and protein, which preserves the pathogen.”

Using this clever technique to gather samples, the researchers were able to demonstrate that the virus that was extracted from the air could infect cells in a lab dish.

The findings from this research should compel people to heed precautions for airborne transmission like improved ventilation, Seema Lakdawala, a respiratory virus expert at the University of Pittsburgh, told The New York Times.

Building the Case

Additional research published in Clinical Infectious Diseases highlights the possibility of airborne spread of COVID-19.

Findings showed COVID-19 patients recruited in Beijing exhaled millions of COVID-19 RNA copies into the air per hour. The researchers conclude that COVID-19 is released into the air by infected patients when they breathe. However, unlike the University of Florida research, the study did not investigate infectivity. 

Even More Evidence

In another study, researchers documented a COVID-19 outbreak that affected nursing home residents and staff in one of seven wards. The outbreak had no impact on the 95 residents or 106 staff from the other wards.

“Suspecting that the ventilation system of the affected ward could have contributed to the outbreak, investigators found that an energy-efficient system had been installed in which indoor air was refreshed only when indoor carbon dioxide (CO2) concentrations detected elevated levels,” according to an article.

“If CO2 levels didn't exceed a certain threshold, unfiltered indoor air was simply recirculated throughout the ward. In contrast, the six unaffected wards were refreshed regularly with outside air.”

The authors’ data suggested the outbreak was caused by aerosol transmission in a situation of inadequate ventilation. 

Taking Action

As evidence of COVID-19 transmission through aerosols grows, dental practitioners can do their part to minimize the risk of transmission using mitigation strategies such as extraoral aerosol evacuation.

Moreover, according to Jose-Luis Jimenez, Fellow of the American Association for Aerosol Research, “the WHO and CDC, among others, must begin communicating the science suggesting aerosol spread of COVID-19 … If not, we hamper our ability to counter the growing health consequences and increasing death toll of COVID-19.” 

Topics: Aerosol Reduction