Study finds COVID-19 'virus-laden aerosol' in air inside Wuhan hospitals that treated patients

This scanning electron microscope image shows SARS-CoV-2, the virus that causes COVID-19, isolated from a patient in the U.S., emerging from the surface of cells cultured in the lab. (Photo by: IMAGE POINT FR - LPN/BSIP/Universal Images Group via Get

A new study found evidence of concentrations of airborne SARS-CoV-2, the virus that causes COVID-19, remaining in the air of Chinese hospitals that treated patients with the disease.

To date, the virus is believed to spread through close contact with infected individuals by inhaling small droplets when an infected person coughs, sneezes or speaks, or through contact with contaminated objects or surfaces.

The study, published this week in the journal Nature, aimed to look at the potential for SARS-CoV-2 to spread through the air.

The researchers collected aerosol samples in and around two hospitals in Wuhan that were treating COVID-19 patients in February and March — including patient areas, medical staff areas and outdoor public areas. Wuhan is the Chinese city where the novel coronavirus was first reported before developing into the now global pandemic.

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One of the hospitals, Renmin Hospital of Wuhan University, treated COVID-19 patients with severe symptoms, while the Wuchang Fangcang Field Hospital was renovated from an indoor sports stadium to quarantine and treat those with mild symptoms.

The team collected more than 30 aerosol samples from 31 different sites. 

Researchers found concentrations of the virus in the air where there were more infected patients, but noted that the concentrations were generally low in areas that were well-ventilated. 

But in other areas, such as patients’ toilet areas that were not ventilated, concentrations were found to be higher.

Researchers also found that concentrations of SARS-CoV-2 were higher in rooms designated for medical staff to remove their protective equipment, suggesting that that virus-laden aerosols can become re-suspended in the air when masks and other gear is removed.

A majority of the sites tested in public areas outside the hospital had “undetectable or very low concentrations,” except for one area outside the entrance to a department store where customers frequently passed through, as well as a site next to Renmin Hospital where patients and others passed by.  

“It is possible that asymptomatic carriers of COVID-19 in the crowd may have contributed as the source of virus-laden aerosol during the sampling period,” the study authors noted.

“The results showed overall low risks in the public venues but do reinforce the importance of avoiding crowded gatherings and implementing early identification and diagnosis of asymptomatic carriers for early quarantine or treatment.”

While it remains unclear whether people can develop COVID-19 through breathing the type of aerosols found in the study, researchers recommended proper ventilation and sterilization of toilets, taking personal protection measures such as wearing masks and avoiding crowds, as well as sanitization of high risk hospital areas and protective apparel before removal. 

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This story was reported from Cincinnati.