Posted on 04/01/2020 4:12:03 AM PDT by Zhang Fei
Abstract
Background:
Conflicting recommendations exist related to which facial protection should be used by health care workers to prevent transmission of acute respiratory infections, including pandemic influenza. We performed a systematic review of both clinical and surrogate exposure data comparing N95 respirators and surgical masks for the prevention of transmissible acute respiratory infections.
Methods:
We searched various electronic databases and the grey literature for relevant studies published from January 1990 to December 2014. Randomized controlled trials (RCTs), cohort studies and case–control studies that included data on health care workers wearing N95 respirators and surgical masks to prevent acute respiratory infections were included in the meta-analysis. Surrogate exposure studies comparing N95 respirators and surgical masks using manikins or adult volunteers under simulated conditions were summarized separately. Outcomes from clinical studies were laboratory-confirmed respiratory infection, influenza-like illness and workplace absenteeism. Outcomes from surrogate exposure studies were filter penetration, face-seal leakage and total inward leakage.
Results:
We identified 6 clinical studies (3 RCTs, 1 cohort study and 2 case–control studies) and 23 surrogate exposure studies. In the meta-analysis of the clinical studies, we found no significant difference between N95 respirators and surgical masks in associated risk of (a) laboratory-confirmed respiratory infection (RCTs: odds ratio [OR] 0.89, 95% confidence interval [CI] 0.64–1.24; cohort study: OR 0.43, 95% CI 0.03–6.41; case–control studies: OR 0.91, 95% CI 0.25–3.36); (b) influenza-like illness (RCTs: OR 0.51, 95% CI 0.19–1.41); or (c) reported workplace absenteeism (RCT: OR 0.92, 95% CI 0.57–1.50). In the surrogate exposure studies, N95 respirators were associated with less filter penetration, less face-seal leakage and less total inward leakage under laboratory experimental conditions, compared with surgical masks.
(Excerpt) Read more at ncbi.nlm.nih.gov ...
Negative pressure rooms? I dealt with that in this morning’s Q&A.
How far can paranoia take us? All the way to mass hysteria.
Today I am answering questions in a separate thread.
In television coverage I noticed several Hospital workers appeared to be wearing an N95 mask which they in turn had covered with a surgical mask.
Maybe to help the N95 last longer?
This whole country is going to look like a giant intifada. Yasser Arafat is back in style.
Sorry, been watching old SNL skits from the 70s with Belushi. Kinda in that mood. Seriously though, would someone working with asbestos be comfortable with a surgical mask?
interesting. Never seen those pics. So TB wasn’t the first disease masks were used for.
[Negative pressure rooms? I dealt with that in this morning’s Q&A.]
Very good point.
Yes. if you can get an N95 it’s the only one you are going to get for a while. wearing a simple mask over the top protects and keeps it clean to help it last longer
The purpose of the regular mask is not to prevent contraction by the person wearing the mask. It is to prevent mucus from coming off his mouth. The only way it helps is reducing the chance to touch your face with unwashed hand.
I just don’t think people realize these N95 masks were not intended to be used outside of negative pressure rooms. To wear them in public was never their intended purpose. Which is why I used to sort of laugh at Asians in Asia wearing them.
Yeah, but. Like a lot of things they work as well or better for some uses other than their original intent and design.
We have a small amount on hand because we live in a rural western area subject to smokey wildfires in many recent years. The N95 seal beats the heck out of surgical masks, which are more intended to prevent medical people from breathing droplets out and into someone's open surgery site than anything else.
Yes, we all know that. Cotton masks are to keep folks from breathing or coughing virus on each other. It works very well when everybody is wearing them in public, like in Taiwan, S. Korea etc.
Don’t you have to factor the difference between regular nurses attending stabilized patients and ER/ ICU staff dealing with multiple active infections? The virus load inflicted upon those working with incoming patients is tremendous. You cannot afford “sick days” at the moment in any staff in either unit.
See my homepage for mask design and other coronavirus-related suggestions by clicking on my name.
[See my homepage for mask design and other coronavirus-related suggestions by clicking on my name.]
Austria now requires mask wearing in all shops.
Watch the video of this screen capture in the following post.
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