3 ms·

No, what you just said is seriously wrong. The CDC even coauthored a paper that found during the SARS-1 outbreak that among contacts of known cases, those untr

No, what you just said is seriously wrong. The CDC even coauthored a paper that found during the SARS-1 outbreak that among contacts of known cases, those untrained people that regularly wore surgical masks had a 70% reduced risk of contracting SARS. 60% for those that wore them intermittently. And in fact, research suggests that masks are actually MORE protective for the people wearing them. Note the following points, with sources (The context is a bit off because I did this research in response to another question, but the points are still pretty much relevant here): 1. Regular old surgical masks (not N95 respirators), when worn by the public without training, had a strong protective effect for the people wearing them during the SARS-CoV-1 outbreak. They reduced the risk of infection by ~70%. (Source: https://wwwnc.cdc.gov/eid/article/10/2/03-0730_article https://wwwnc.cdc.gov/eid/article/10/2/03-0730_article) 2. Despite being very different in their ability to actually filter out fine particles, N95 respirators and surgical masks actually show no significant difference in their ability to prevent diagnosed respiratory infections including influenza, when worn by healthcare workers according to two large meta-studies. Though both had a protective effect over no mask. (Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4868605/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4868605/) (2nd source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5779801/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5779801/) 3. Improvised, homemade masks have only a marginally lower filtration efficiency than surgical masks (which we established are about as effective as an N95 respirator anyway). (Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2440799/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2440799/) (2nd source: https://www.researchgate.net/publication/258525804_Testing_the_Efficacy_of_Homemade_Masks_Would_They_Protect_in_an_Influenza_Pandemic https://www.researchgate.net/publication/258525804_Testing_t...) 4. There is evidence in the studies linked in item 2 that hand hygiene alone did not demonstrate much of a protective effect (for civilians caring for a sick family member) against transmission of influenza compared to use of any type of mask. 5. When infected people wear a mask, it helps reduce the amount of viral shedding which occurs, presumably making them less likely to infect others. (Source: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3591312/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3591312/)

fiter 7y ago
From your study on point 2: "Results of our systematic review and meta-analysis show that there was no significant difference between N95 respirators and surgical masks when used by health care workers to prevent transmission of acute respiratory infections from patients. However, wide 95% CIs from our meta-analysis must be interpreted as insufficient evidence to determine whether there is a clinically significant difference." What the study says is that we don't have enough information. As an example, one of the studies referenced in that study gives odds of 0.58 for getting infected with surgical and 0.42 with N95. Bonus quote: "Furthermore, we do not have an adequate understanding of the number, size and dispersion of the droplets that contain live, infectious particles produced by infected patients.56 A laboratory-based study reported data that humans infected with influenza rarely produce aerosols that contain infectious viral particles.57 In 2 other laboratory studies, participants infected with influenza produced droplets containing viral RNA, but viral RNA could not be detected on manikin headforms or on filters of breathing manikins at distances as close as 0.1 m following participants breathing, counting, coughing or laughing.7"
- labcomputer 7y ago
  I don't understand your point. The quote you're referring to, regarding 95% CIs, in context specifically applies to comparing surgical masks vs. N95 respirators, not mask vs. no-mask. In other words, surgical masks are not shown to be worse than N95 respirators. That's in complete agreement with the point 2 that you're apparently trying to refute.

fiter 7y ago

From your study on point 2: "Results of our systematic review and meta-analysis show that there was no significant difference between N95 respirators and surgical masks when used by health care workers to prevent transmission of acute respiratory infections from patients. However, wide 95% CIs from our meta-analysis must be interpreted as insufficient evidence to determine whether there is a clinically significant difference." What the study says is that we don't have enough information. As an example, one of the studies referenced in that study gives odds of 0.58 for getting infected with surgical and 0.42 with N95. Bonus quote: "Furthermore, we do not have an adequate understanding of the number, size and dispersion of the droplets that contain live, infectious particles produced by infected patients.56 A laboratory-based study reported data that humans infected with influenza rarely produce aerosols that contain infectious viral particles.57 In 2 other laboratory studies, participants infected with influenza produced droplets containing viral RNA, but viral RNA could not be detected on manikin headforms or on filters of breathing manikins at distances as close as 0.1 m following participants breathing, counting, coughing or laughing.7"

labcomputer 7y ago
I don't understand your point. The quote you're referring to, regarding 95% CIs, in context specifically applies to comparing surgical masks vs. N95 respirators, not mask vs. no-mask. In other words, surgical masks are not shown to be worse than N95 respirators. That's in complete agreement with the point 2 that you're apparently trying to refute.