Thread by @WHO

WHO issued an updated scientific brief on #COVID19 transmission, which provides information on how, when and in which settings the virus spreads between people: bit.ly/2W251Ma

#COVID19 transmission occurs primarily through direct, indirect or close contact with infected people through their saliva and respiratory secretions, or through their respiratory droplets, which are expelled when they cough, sneeze, talk or sing. bit.ly/2W251Ma

Airborne #COVID19 transmission can occur in health care settings where specific medical procedures generate very small droplets - aerosols. bit.ly/2W251Ma

Some #COVID19 outbreak reports related to crowded indoor spaces have suggested the possibility of aerosol transmission combined with droplet transmission e.g. during choir practice, in restaurants or gyms.
We need more studies to understand such outbreaks bit.ly/2W251Ma

Respiratory droplets from infected individuals can also land on objects or other surfaces. It is likely that people can also be infected with #COVID19 by touching these surfaces & touching their 👀, 👃 or 👄 before cleaning their 👐. bit.ly/2W251Ma

Based on what we currently know, #COVID19 transmission primarily occurs when people are showing symptoms, but can also happen just before they develop symptoms - when they are in close proximity to others for prolonged periods of time. bit.ly/2W251Ma

While people who never develop #COVID19 symptoms can also pass the virus to others, it is still not clear to what extent this occurs. More research is needed in this area. bit.ly/2W251Ma

Urgent research is needed on:
-transmission routes
-airborne transmission in the absence of aerosol generating procedures
-dose of virus that will result in infection
-settings and risk factors for superspreading events
-extent of asymptomatic and pre-symptomatic transmission

Q&A on how #COVID19 is transmitted

👉 bit.ly/3fcG7kQ