LET"S CLEAR THE AIR - WHO Official Defends Guidance: 'We're Not Seeing' Airborne Transmission' - HOWEVER? “I think the answer will be, aerosolization occurs rarely but not never,”

“YOU HAVE TO DISTINGUISH BETWEEN WHAT’S POSSIBLE AND WHAT’S ACTUALLY HAPPENING.”

Source: MICROBIOLOGIST AND PHYSICIAN STANLEY PERLMAN OF THE UNIVERSITY OF IOWA. 

When a new virus blasts out of the animals that harbored it and into people, experts can usually say, thank goodness it’s not like measles. That virus is more contagious than any others known to science: Each case of measles causes an astronomical 12 to 18 new cases, compared to about six for polio, smallpox, and rubella. Each case of the new coronavirus is estimated to cause two to three others.

The reason the measles is so, well, viral, is that the microbe is so small and hardy that it is able to stay suspended in the air where an infected person coughed or sneezed for up to two hours, making it one of the only viruses that can exist as a true aerosol.

Now there are conflicting reports on whether the new coronavirus can. The studies suggesting that it can be aerosolized are only preliminary, and other research contradicts it, finding no aerosolized coronavirus particles in the hospital rooms of Covid-19 patients.

The weight of the evidence suggests that the new coronavirus can exist as an aerosol — a physics term meaning a liquid or solid (the virus) suspended in a gas (like air) — only under very limited conditions, and that this transmission route is not driving the pandemic. 

But “limited” conditions does not mean “no” conditions, underlining the need for health care workers to have high levels of personal protection, especially when doing procedures such as intubation that have the greatest chance of creating coronavirus aerosols. “I think the answer will be, aerosolization occurs rarely but not never,” said microbiologist and physician Stanley Perlman of the University of Iowa. 

“You have to distinguish between what’s possible and what’s actually happening.”

A World Health Organization official says the evidence so far shows that the virus that causes COVID-19 is primarily transmitted through "respiratory droplets and contact routes" — from coughs and sneezes — and doesn't seem to linger in the air.

The WHO's guidance, first published Friday, has been met with some criticism from virus transmission experts.

Dr. Hanan Balkhy, assistant director-general for antimicrobial resistance at the WHO, talked with All Things Considered on Monday about the organization's guidelines. Here is an excerpt.

How much evidence do you need to persuade the WHO to rethink or update or think differently about transmission of COVID-19?

We don't need to be persuaded but we need to have the evidence that it actually is being spread through a specific route that we're not seeing right now. ... Let me give you a simple example. We have hospitals that have worked on developing units for COVID patients. And those patients have coughing, sneezing, in ICUs, they're scoping them.

If we were to have airborne transmission, we would see cases with no contact before getting ill with that disease. That's just one example.

Source WHO https://www.npr.org/sections/coronavirus-live-updates/2020/03/30/823905477/who-official-defends-guidance-we-re-not-seeing-airborne-transmission

Source: https://www.statnews.com/2020/03/16/coronavirus-can-become-aerosol-doesnt-mean-doomed/