Jeb, here's your post from yesterday morning around 9AM regarding masks...
07-22-2020, 08:05 AM
Originally posted by
First Time, Long Time View Post
It's a novel coronavirus meaning it is a new strain of a previously known type. So yes it is new.
In regards to masks. There is nothing new about how this virus interacts with mask wearing than viruses researched from the previous number of decades.
https://wwwnc.cdc.gov/eid/article/26/5/19-0994_article
“In our systematic review, we identified 10 RCTs [randomized controlled trials] that reported estimates of the effectiveness of face masks in reducing laboratory-confirmed influenza virus infections in the community from literature published during 1946–July 27, 2018. In pooled analysis, we found no significant reduction in influenza transmission with the use of face masks…”
“Disposable medical masks (also known as surgical masks) are loose-fitting devices that were designed to be worn by medical personnel to protect accidental contamination of patient wounds, and to protect the wearer against splashes or sprays of bodily fluids… There is limited evidence for their effectiveness in preventing influenza virus transmission either when worn by the infected person for source control or when worn by uninfected persons to reduce exposure.
Our systematic review found no significant effect of face masks on transmission of laboratory-confirmed influenza.”
“In this review, we did not find evidence to support a protective effect of personal protective measures or environmental measures in reducing influenza transmission.”
“We did not find evidence that surgical-type face masks are effective in reducing laboratory-confirmed influenza transmission, either when worn by infected persons (source control) or by persons in the general community to reduce their susceptibility…”
OK Jeb, here's a link to an article by the University of California San Francisco...
https://www.ucsf.edu/news/2020/06/41...-masks-prevent
Here's a few excerpts:
"But health experts say the evidence is clear that masks can help prevent the spread of COVID-19 and that the more people wearing masks, the better."
Why did the CDC change its guidance on wearing masks?
The original CDC guidance partly was based on what was thought to be low disease prevalence earlier in the pandemic, said Chin-Hong.
“So, of course, you’re preaching that the juice isn’t really worth the squeeze to have the whole population wear masks in the beginning – but that was really a reflection of not having enough testing, anyway,” he said. “We were getting a false sense of security.”
Rutherford was more blunt. The legitimate concern that the limited supply of surgical masks and N95 respirators should be saved for health care workers should not have prevented more nuanced messaging about the benefits of masking. “We should have told people to wear cloth masks right off the bat,” he said.
What evidence do we have that wearing a mask is effective in preventing COVID-19?
There are
several strands of evidence supporting the efficacy of masks.
One category of evidence comes from laboratory studies of respiratory droplets and the ability of various masks to block them.
An experiment using high-speed video found that hundreds of droplets ranging from 20 to 500 micrometers were generated when saying a simple phrase, but that nearly all these droplets were blocked when the mouth was covered by a damp washcloth.
Another study of people who had influenza or the common cold found that wearing a surgical mask significantly reduced the amount of these respiratory viruses emitted in droplets and aerosols.
But the strongest evidence in favor of masks come from studies of real-world scenarios. “The most important thing are the epidemiologic data,” said Rutherford. Because it would be unethical to assign people to not wear a mask during a pandemic, the epidemiological evidence has come from so-called “experiments of nature.”
A recent study published in
Health Affairs, for example, compared the COVID-19 growth rate before and after mask mandates in 15 states and the District of Columbia. It found that mask mandates led to a slowdown in daily COVID-19 growth rate, which became more apparent over time. The first five days after a mandate, the daily growth rate slowed by 0.9 percentage-points compared to the five days prior to the mandate; at three weeks, the daily growth rate had slowed by 2 percentage-points.
Finally....
Does the type of mask matter?
Studies have
compared various mask materials, but for the general public, the most important consideration may be comfort. The best mask is one you can wear comfortably and consistently, said Chin-Hong. N95 respirators are only necessary in medical situations such as intubation. Surgical masks are generally more protective than cloth masks, and some people find them lighter and more comfortable to wear.
The bottom line is that any mask that covers the nose and mouth will be of benefit.
“The concept is risk reduction rather than absolute prevention,” said Chin-Hong. “You don’t throw up your hands if you think a mask is not 100 percent effective. That’s silly. Nobody’s taking a cholesterol medicine because they’re going to prevent a heart attack 100 percent of the time, but you’re reducing your risk substantially.”
You asked for evidence regarding the efficacy of masks and, I believe what I've provided above proves their effectiveness. How are you going to change your argument now? Can't wait to see what type of pretzel you become...