Thread by @jeffgilchrist

COVID-19: Hospitals still using outdated droplet protection policies

A friend's recent visit to @MGHToronto hospital in Toronto shows droplet protection policies are still in full effect. 🧵1/ @DavidElfstrom @kprather88 @linseymarr @jljcolorado @DFisman @imgrund

The posted PPE/N95 checklist (see image) is dated more than a year ago and still calls for N95 protection only when certain aerosol generating procedures (AGPs) are present. I fixed it for them... 2/

Ironically breathing, talking, exercising, shouting, and coughing generates more aerosols than the last two AGPs on their list (NIPPV and HHFNO) which were measured in this research study ( …-publications.onlinelibrary.wiley.com/doi/10.1111/an… ). 3/

So if @MGHToronto is worried about aerosols from NIPPV and HHFNO procedures then they should be even more concerned about suspected, presumed, or confirmed COVID-19 cases that are doing AGPs such as breathing, talking, and coughing which generate even more. 4/

Do N95s actually work better than surgical/procedure masks? Yes, a randomized clinical trial (RCT) by MacIntyre in 2013 found that continuous use of N95 resulted in statistically significant reduction in clinical respiratory illness (CRI)... 5/

...and bacterial colonization compared to medical masks and targeted N95 that are only used for some procedures like AGPs ( atsjournals.org/doi/full/10.11… ). 6/

But you have heard some infectious disease specialists claim that N95 doesn't work any better than procedure masks and they cite some systematic reviews? Well those reviews have some serious errors which you can read more about here (

https://twitter.com/CPita3/status/1452498957930741761

). 7/

If people breathing, talking, shouting, and coughing generate more aerosols than some medical AGPs wouldn't that mean aerosols with infectious COVID-19 virus would travel more than 2m away from patients and into hospital corridors on COVID wards? 8/

Yes, that is exactly what that means. A study measured this and found there was significant transfer of viruses from COVID-19 patient rooms to corridors ( ncbi.nlm.nih.gov/pmc/articles/P… ) where nurses, staff, and others are only wearing protection from close-contact droplets. 9/

A second study also measured COVID-19 and multiple other virus, bacterial and fungal pathogens in the air on a COVID ward ( medrxiv.org/content/10.110… ). 10/

They detected airborne COVID-19 virus on all 5 days before they started filtering the air, but none of the 5 days when the additional air filtration system was active, then detected again on 4 of the 5 days after the extra filtration was turned off. 11/

It really is time for hospitals and policies to recognize that COVID-19 and other respiratory viruses are airborne and adopt appropriate protection for people ( science.org/doi/10.1126/sc… ). 12/