Lancet: COVID-19 transmission—up in the air

On Oct 5, 2020, the CDC updated their COVID-19 webpage to say that there is growing evidence that COVID-19 infection can occur from airborne exposure to the virus under certain circumstances. Cases of transmission from people more than 2 m apart have occurred but in enclosed spaces with poor ventilation, and typically with extended exposure to an infected person of more than 30 min. The CDC have been clear to point out that most infections are spread through close contact and that airborne transmission is not the primary route of transmission.

Whether droplet or airborne transmission is the main route, the risk of infection is known to be much lower outside where ventilation is better. As winter approaches in the northern hemisphere, the opportunity to socialise and exercise outdoors becomes more challenging and concerns are growing over the increased risk of transmission of COVID-19. Public health guidance now needs to advise people how to navigate risk in indoor settings and wearing facemasks is becoming mandatory in many countries for travelling on public transport, indoor shopping, and gatherings. Facemasks and shields offer protection from larger droplets but their effectiveness against airborne transmission is less certain. Advice on spending time indoors should also focus on improved ventilation and avoiding crowded spaces.

Länk LANCET