Covid-19

Source of photo: https://www.straitstimes.com/singapore/health/ncid-studying-to-see-if-virus-naturally-airborne

On July 7, The World Health Organization (WHO) has announced that there is evidence of the coronavirus being airborne, after a group of scientists urged the global body to update its guidance on how the respiratory disease passes between people.

Maria Van Kerkhove, technical lead on the COVID-19 pandemic at the WHO, mentioned at a news briefing "We have been talking about the possibility of airborne transmission and aerosol transmission as one of the modes of transmission of COVID-19,"

Why did WHO deny COVID-19 being airborne previously?

Previously, WHO said that the virus that causes the COVID-19 respiratory disease spreads primarily through small droplets expelled from the nose and mouth of an infected person that quickly sink to the ground. There wasn’t a clear evidence that signifies or shows that the virus spreads through air. 

How does the coronavirus spread?

According to the CDC, the virus that causes COVID-19 is thought to spread mainly from person to person, mainly through respiratory droplets produced when an infected person coughs, sneezes, or talks. These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs. Spread is more likely when people are in close contact with one another (within about 6 feet).

COVID-19 seems to be spreading easily and sustainably in the community in many affected geographic areas. Community spread means people have been infected with the virus in an area, including some who are not sure how or where they became infected.

Read more about the spread of COVID-19 and how to protect yourself here: 

https://www.cdc.gov/coronavirus/2019-ncov/prevent-getting-sick/how-covid-spreads.html

Why may COVID-19 be considered airborne now?

On 6 July, in an open letter to the Geneva-based agency, published in the Clinical Infectious Diseases journal, 239 scientists in 32 countries outlined evidence that they say shows floating virus particles can infect people who breathe them in.

Because those smaller exhaled particles can linger in the air, the scientists are urging WHO to update its guidance.

Speaking at Tuesday's briefing in Geneva, Benedetta Allegranzi, the WHO's technical lead for infection prevention and control, said there was evidence emerging of airborne transmission of the coronavirus, but that it was not definitive.

"The possibility of airborne transmission in public settings - especially in very specific conditions, crowded, closed, poorly ventilated settings that have been described, cannot be ruled out," she said.

"However, the evidence needs to be gathered and interpreted, and we continue to support this."

If the evidence is confirmed, it may affect guidelines for indoor spaces.

Another point of view

Another signatory - Professor Benjamin Cowling of Hong Kong University - told the BBC the finding had "important implications".

"In healthcare settings, if aerosol transmission poses a risk then we understand healthcare workers should really be wearing the best possible preventive equipment... and actually the World Health Organization said that one of the reasons they were not keen to talk about aerosol transmission of Covid-19 is because there's not a sufficient number of these kind of specialised masks for many parts of the world," he said.

"And in the community, if we're thinking about aerosol transmission being a particular risk, then we need to think about how to prevent larger super spreading events, larger outbreaks and those occur in indoor environments with poor ventilation, with crowding and with prolonged close contact."

Adapted from: https://www.channelnewsasia.com/news/world/covid-19-who-acknowledges-evidence-airborne-spread-12910906

https://www.bbc.com/news/world-53329946