CLEVELAND, Ohio — New research shows the potential for the coronavirus to move through the air, but there’s not enough evidence to change the way we approach the virus yet.
Current social distancing guidelines are based on the belief that COVID-19 is transmitted by respiratory droplets. That means the virus spreads through liquid released when a patient coughs or sneezes.
But is the coronavirus airborne? Airborne viruses can travel without respiratory droplets to carry them, said Mark Cameron, an associate professor at Case Western Reserve University.
“It doesn’t simply rely on being coughed on or respiratory secretions within a six-foot radius of a patient,” he said. “Being airborne would allow a virus to travel further than that. There have been hints.”
Air samples taken inside hospitals, in COVID-19 patients’ rooms and the hallways outside, tested positive for the coronavirus, according to University of Nebraska research. The study is published on a pre-publication research site, but is not yet peer-reviewed.
The samples were taken farther than 6 feet away from patient beds. Analysis of the samples found in the air did not indicate the presence of viral replication.
A university post noted that this was not conclusive evidence that the virus is airborne, and that further research is needed to see if live virus was captured and determine the risk of transmission through the air.
An earlier study in the New England Journal of Medicine nebulized the virus and studied the spray in the air in a controlled lab environment. Researchers found that the virus remained in the air for three hours after it was sprayed, but did not study whether or not it spread.
The University of Nebraska study was conducted in a clinical environment, with isolated coronavirus patients. A next step, Cameron said, could be to move away from an area with a high concentration of the illness and see whether the virus shows up.
Otherwise, the virus could be spreading by landing on various surfaces, or by being sucked up into vents.
A study conducted in hospitals in Wuhan, China, found that testing sites in ICU, CCU and general patient rooms, as well as a patient hall had undetectable or low airborne coronavirus concentration. Samples in the intensive care unit and in a patient toilet tested positive for the coronavirus.
Researchers concluded this meant precautions like negative-pressure rooms, which prevents contaminated air from leaving the rooms, and regular cleaning were working.
The study also examined samples from the air in public areas in Wuhan. Though amounts of the virus were undetectable or very low, there were higher levels in a gathering place in front of a department store.
“The results showed overall low risks in the public venues overall but do reinforce the importance of avoiding crowded gatherings and implementing early identification and diagnosis of asymptomatic carriers for early quarantine or treatment,” the study reads.
The study also suggests that regular mask-wearing in public places and on transit could be helpful in halting the spread of the disease.
The Centers for Disease Control and Prevention are reportedly reconsidering recommendations on whether people should wear masks in public, the Washington Post reported. The recommendations would be for “do-it yourself” cloth masks, not surgical masks or N-95 respirator masks.
Neither the CDC or the World Health Organization currently recommend people wearing masks every time they’re in public.
Cameron said if the disease is airborne, hospitals would need to drastically shift how patients are isolated, with stricter quarantine measures. The personal protective equipment healthcare workers wear would not necessarily change, with the right masks fitted correctly as a line of defense.
“The virus being airborne would not likely change what us in our homes should be doing, including whether we wear a mask or not,” he said. “It would change the decisions that would have to be made at some point, in how long we shelter in place or stay at home, and how long non-essential businesses stay open.”
A similar virus, SARS-CoV-1, which is about 80 percent identical to COVID-19, is not spread in the air.
“There are indicators that this should be part of the discussion on this coronavirus is able to spread so well,” Cameron said. “However, coronaviruses in general are viruses that transmit through respiratory transmission and are not airborne.”