Will coronavirus 2019 (COVID-19) be transmitted through the air? Has WHO revised relevant protection guidelines based on recent academic research on the aerosol transmission? the answer is negative.
Today, the WHO said that based on current evidence, 2019 coronavirus disease is transmitted from person to person mainly through respiratory droplets.
When a person comes into close contact (within 1 meter) with someone who has symptoms of a respiratory tract infection (such as coughing or sneezing) and thus has the opportunity to come in contact with a potentially infectious droplet, droplet transmission (flying) (The diameter of the foam is generally 5-10 microns). Droplet transmission may also occur through contact with the surface of objects in the environment surrounding the infected person.
Therefore, if you inhale the virus within 1 meter of the 2019 Coronavirus patient, or touch a contaminated surface before washing your hands, and then touch your eyes, nose or mouth, you may be infected.
Air transmission is different from droplet transmission (air transmission is usually transmitted through particles smaller than 5 microns in diameter). These particles come from the evaporation of larger droplets or are present on dust particles. They may stay in the air for a longer period of time and can spread over distances of more than 1 meter.
For 2019 Coronavirus disease, the virus may be transmitted through the air under certain circumstances and during medical procedures that can generate aerosols (eg, tracheal intubation, bronchoscopy, open suction, spray therapy, intubation Anterior hand-controlled ventilation, patient prone position, ventilator offline, non-invasive positive pressure ventilation, tracheostomy, and cardiopulmonary resuscitation).
In an analysis of 75,465 patients with coronavirus in China in 2019, no cases of airborne transmission were reported.
To date, several academic papers have explored whether new coronaviruses can be detected in the air, with the aim of presenting preliminary evidence that the virus may be transmitted through the air. Care should be taken in interpreting the results of these preliminary studies.
The New England Journal of Medicine recently published an article on how long a new coronavirus can survive in the environment. The research team used a three-jet Collison nebulizer and a Goldberg drum to artificially generate viral aerosols under laboratory conditions and observed that the aerosols can be suspended in the air for a period of about 3 hours.
It should be noted that the Goldberg drum is a high energy device and does not meet the general situation of human cough. Moreover, even if it is found that the new coronavirus can persist in the form of aerosol particles for 3 hours under such conditions, the conditions are not consistent with the clinical operating environment in which the aerosol is generated.
Based on the current evidence, WHO retains the original recommendation that anti-droplet and contact isolation measures be recommended for medical care personnel of patients with coronavirus disease in 2019 and that anti-exposure and air protection be recommended during aerosol-generating diagnostic procedures. Spread quarantine measures.
WHO's recommendations to the public also remain unchanged, namely:
Keep a distance of at least 1 meter from others;
Disinfect frequently contacted surfaces;
Wash your hands frequently and thoroughly;
Avoid touching your eyes, mouth, and nose with your hands.
Special Report: Fighting The New Coronavirus
