Study shows SARS-COV-2 can be carried in aerosol up to 4 metres from infected person
A new study by Chinese researchers to check aerosol and surface distribution of SARS-COV-2 in an Intensive Care Unit (ICU) and General Ward (GW) with COVID-19 infected patients found that the virus can be detected in the air up to 4 metres away from patients. In addition, they found the virus was widely distributed on floors and recommend that persons disinfect shoe soles before walking out of wards containing COVID-19 patients.
They also found the virus on computer mice, trash cans, and sickbed handrails.
The early release study was published April 10 in Emerging Infectious Diseases.
The aerosol distribution of the virus has been controversial with previous findings based on very small studies which may not reflect real conditions in a hospital at full capacity. This new study, however, tested surface and air samples in a busy hospital in Wuhan from February 19 through March 2 at the height of outbreak in that city.
The study is particularly pertinent for healthcare workers treating COVID-19 patients and offers a number of conclusions and recommendations.
- SARS-CoV-2 was widely distributed in the air and on object surfaces in both the ICU and GW, implying a potentially high infection risk for medical staff and other close contacts.
- The SARS-CoV-2 aerosol distribution characteristics in the GW indicate that the transmission distance of SARS-CoV-2 might be 4 metres.
- The environmental contamination was greater in the ICU than in the GW; thus, stricter protective measures should be taken by medical staff working in the ICU.
They also found that as the virus settles on the floor it could be tracked around the hospital where healthcare workers from the ICU and GW had walked, such as the floor of the pharmacy.
On this evidence the authors highly recommend that persons disinfect shoe soles before walking out of wards containing COVID-19 patients.
The researchers note that as of March 30 no healthworkers at the hospital had become infected and point out that appropriate precautions can effectively prevent infection.
The authors note that the results of their nucleic acid test do not indicate the amount of viable virus. And that because the minimal infectious dose is unknown, the aerosol transmission distance cannot be strictly determined.
doi: 10.3201/eid2607.200885
