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Masks have been around for over 100 yrs. You should be skeptical that suddenly they were discovered as the best primary fight against viruses. Review of data indicates ineffectiveness, or lack of evidence that masks stop the spread in a population. Evidence provided here: 1/
Start with the 2020 CDC meta-study of 10 RTCs related to masks:
"In pooled analysis, we found no significant reduction in influenza transmission with the use of face masks"
"There are major gaps in our knowledge of person-to-person transmission" 2/
https://wwwnc.cdc.gov/eid/article/26/5/19-0994_article?fbclid=IwAR2V1hPqN0WKb2kXVExP_1UE9ARvru6mtPZvZN0w1jx0S3l3fXLhxMP_bXs
"In pooled analysis, we found no significant reduction in influenza transmission with the use of face masks"
"There are major gaps in our knowledge of person-to-person transmission" 2/
https://wwwnc.cdc.gov/eid/article/26/5/19-0994_article?fbclid=IwAR2V1hPqN0WKb2kXVExP_1UE9ARvru6mtPZvZN0w1jx0S3l3fXLhxMP_bXs
2015 Unmasking the surgeons: the evidence base behind the use of facemasks in surgery
"overall there is a lack of substantial evidence to support claims that facemasks protect either patient or surgeon from infectious contamination" 3/
https://www.researchgate.net/publication/278791186_Unmasking_the_surgeons_the_evidence_base_behind_the_use_of_facemasks_in_surgery/link/5bf6e543299bf1a0202c2768/download
"overall there is a lack of substantial evidence to support claims that facemasks protect either patient or surgeon from infectious contamination" 3/
https://www.researchgate.net/publication/278791186_Unmasking_the_surgeons_the_evidence_base_behind_the_use_of_facemasks_in_surgery/link/5bf6e543299bf1a0202c2768/download
2010 Is Routine Use of a Face Mask Necessary in the Operating Room?
“A recent review concluded that it is not clear whether face masks prevent surgical wound infections, and the scientific evidence for this practice is weak and insufficient." 4/
https://pubs.asahq.org/anesthesiology/article/113/6/1447/9572/Is-Routine-Use-of-a-Face-Mask-Necessary-in-the
“A recent review concluded that it is not clear whether face masks prevent surgical wound infections, and the scientific evidence for this practice is weak and insufficient." 4/
https://pubs.asahq.org/anesthesiology/article/113/6/1447/9572/Is-Routine-Use-of-a-Face-Mask-Necessary-in-the
Postoperative wound infections and surgical face masks 1991
3088 patients over 115 wks.
"results indicate that the use of face masks might be reconsidered. Masks...have not been proven to protect the patient operated by a healthy operating team.” 5/
https://link.springer.com/article/10.1007/BF01658736
3088 patients over 115 wks.
"results indicate that the use of face masks might be reconsidered. Masks...have not been proven to protect the patient operated by a healthy operating team.” 5/
https://link.springer.com/article/10.1007/BF01658736
Household RTC of hand washing and face masks to reduce influenza transmission Bangkok 2011
Most studies on masks have too many confounding factors.
“Influenza transmission was not reduced by interventions to promote hand washing and face mask use." 6/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4634545/
Most studies on masks have too many confounding factors.
“Influenza transmission was not reduced by interventions to promote hand washing and face mask use." 6/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4634545/
Impact of Non-Pharmaceutical Interventions on URIs and Influenza in Crowded, Urban Households 2010
"there was no detectable additional benefit of hand sanitizer or face masks over targeted education on overall rates of URIs." 7/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2821845/
"there was no detectable additional benefit of hand sanitizer or face masks over targeted education on overall rates of URIs." 7/
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2821845/
Facemasks, hand hygiene, and influenza among young adults: a randomized intervention trial 2012
"Masks alone did not provide a benefit, suggesting that single personal protective interventions do not protect against incidence of ILI or influenza." 8/
https://www.researchgate.net/publication/221796236_Facemasks_Hand_Hygiene_and_Influenza_among_Young_Adults_A_Randomized_Intervention_Trial/link/0c96052409539cd8be000000/download
"Masks alone did not provide a benefit, suggesting that single personal protective interventions do not protect against incidence of ILI or influenza." 8/
https://www.researchgate.net/publication/221796236_Facemasks_Hand_Hygiene_and_Influenza_among_Young_Adults_A_Randomized_Intervention_Trial/link/0c96052409539cd8be000000/download
Mask Use, Hand Hygiene, and Seasonal Influenza-Like Illness among Young Adults: A Randomized Intervention Trial 2010
Here masks do appear to have + effect. However, very minor (32 vs 26%) and study has lots of issues. 9/
https://www.researchgate.net/publication/41101096_Mask_Use_Hand_Hygiene_and_Seasonal_Influenza-Like_Illness_among_Young_Adults_A_Randomized_Intervention_Trial
Here masks do appear to have + effect. However, very minor (32 vs 26%) and study has lots of issues. 9/
https://www.researchgate.net/publication/41101096_Mask_Use_Hand_Hygiene_and_Seasonal_Influenza-Like_Illness_among_Young_Adults_A_Randomized_Intervention_Trial
Face Mask Use and Control of Respiratory Virus Transmission in Households 2009
Lots of issues with this study. "although our study suggests that community use of face masks is unlikely to be effective...adherent mask users had a significant reduction" 10/
https://www.researchgate.net/publication/23979785_Face_Mask_Use_and_Control_of_Respiratory_Virus_Transmission_in_Households
Lots of issues with this study. "although our study suggests that community use of face masks is unlikely to be effective...adherent mask users had a significant reduction" 10/
https://www.researchgate.net/publication/23979785_Face_Mask_Use_and_Control_of_Respiratory_Virus_Transmission_in_Households
Preliminary Findings of a Randomized Trial of Non-Pharmaceutical Interventions to Prevent Influenza Transmission in Households 2008
A lot lacking with this study, but clearly no trend. 11/
https://www.researchgate.net/publication/5293905_Preliminary_Findings_of_a_Randomized_Trial_of_Non-Pharmaceutical_Interventions_to_Prevent_Influenza_Transmission_in_Households
A lot lacking with this study, but clearly no trend. 11/
https://www.researchgate.net/publication/5293905_Preliminary_Findings_of_a_Randomized_Trial_of_Non-Pharmaceutical_Interventions_to_Prevent_Influenza_Transmission_in_Households
Facemasks and Hand Hygiene to Prevent Influenza Transmission in Households: A Cluster RCT 2009
Symptomatic patients at home. No significant difference between handwashing and handwashing/masks. 12/
https://www.researchgate.net/publication/26714438_Facemasks_and_Hand_Hygiene_to_Prevent_Influenza_Transmission_in_Households_A_Cluster_Randomized_Trial
Symptomatic patients at home. No significant difference between handwashing and handwashing/masks. 12/
https://www.researchgate.net/publication/26714438_Facemasks_and_Hand_Hygiene_to_Prevent_Influenza_Transmission_in_Households_A_Cluster_Randomized_Trial
Face masks to prevent transmission of influenza virus : a systematic review 2010
Direct test of masks and pietry dishes confirmed surgical/N95 masks effectiveness (Johnson 2009). However, virtually all other studies fail to show a difference in healthcare/community settings. 13/
Direct test of masks and pietry dishes confirmed surgical/N95 masks effectiveness (Johnson 2009). However, virtually all other studies fail to show a difference in healthcare/community settings. 13/
Disease Mitigation Measures 2006
"ordinary surgical mask does little to prevent inhalation of small droplets bearing influenza virus...pores in the mask become blocked by moisture...and the air stream simply diverts around the mask" 14/
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.552.1109&rep=rep1&type=pdf
"ordinary surgical mask does little to prevent inhalation of small droplets bearing influenza virus...pores in the mask become blocked by moisture...and the air stream simply diverts around the mask" 14/
http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.552.1109&rep=rep1&type=pdf
2015 cluster RCT of cloth masks for HCWs:
"the results caution against the use of cloth masks...Moisture retention, reuse of cloth masks and poor filtration may result in increased risk of infection...cloth masks should not be recommended for HCWs. 15/
https://bmjopen.bmj.com/content/5/4/e006577
"the results caution against the use of cloth masks...Moisture retention, reuse of cloth masks and poor filtration may result in increased risk of infection...cloth masks should not be recommended for HCWs. 15/
https://bmjopen.bmj.com/content/5/4/e006577
World Health Org (WHO) Advice June 2020
"widespread use of masks by healthy people in the community setting is not yet supported by high quality or direct scientific evidence and there are potential benefits and harms to consider" 16/
https://www.who.int/publications/i/item/advice-on-the-use-of-masks-in-the-community-during-home-care-and-in-healthcare-settings-in-the-context-of-the-novel-coronavirus-(2019-ncov)-outbreak
"widespread use of masks by healthy people in the community setting is not yet supported by high quality or direct scientific evidence and there are potential benefits and harms to consider" 16/
https://www.who.int/publications/i/item/advice-on-the-use-of-masks-in-the-community-during-home-care-and-in-healthcare-settings-in-the-context-of-the-novel-coronavirus-(2019-ncov)-outbreak
WHO Advice on the use of masks for children in the community in the context of COVID-19
Lots of negatives here.
Should do no harm, not negatively impact development and learning, no masks up to age 5, not for cognitive or respiratory 17/
https://www.who.int/publications/i/item/WHO-2019-nCoV-IPC_Masks-Children-2020.1
Lots of negatives here.
Should do no harm, not negatively impact development and learning, no masks up to age 5, not for cognitive or respiratory 17/
https://www.who.int/publications/i/item/WHO-2019-nCoV-IPC_Masks-Children-2020.1
Surgical masks as source of bacterial contamination during operative procedures 2018
The pictures who why surgeons wear masks. 18/
https://www.researchgate.net/publication/326039569_Surgical_masks_as_source_of_bacterial_contamination_during_operative_procedures
The pictures who why surgeons wear masks. 18/
https://www.researchgate.net/publication/326039569_Surgical_masks_as_source_of_bacterial_contamination_during_operative_procedures
Scandinavia countries do not recommend.
"There is no evidence that the extensive use of masks by healthy people will reduce infections"
"there is no scientific basis for recommending the general use of face masks."
"face masks can cause more harm than good." 19/
"There is no evidence that the extensive use of masks by healthy people will reduce infections"
"there is no scientific basis for recommending the general use of face masks."
"face masks can cause more harm than good." 19/
NEJM Universal Masking in Hospitals in the Covid-19 Era
“We know that wearing a mask outside health care facilities offers little, if any, protection from infection”
“desire for widespread masking is a reflexive reaction to anxiety over the pandemic” 20/ https://www.nejm.org/doi/full/10.1056/NEJMp2006372?query=TOC
“We know that wearing a mask outside health care facilities offers little, if any, protection from infection”
“desire for widespread masking is a reflexive reaction to anxiety over the pandemic” 20/ https://www.nejm.org/doi/full/10.1056/NEJMp2006372?query=TOC
WHO -Non-pharmaceutical measures for mitigating the risk and impact of epidemic and pandemic influenza 2019
“Although...no evidence that this is effective in reducing transmission, there is mechanistic plausibility for the potential effectiveness” 21/
https://www.who.int/influenza/publications/public_health_measures/publication/en/
“Although...no evidence that this is effective in reducing transmission, there is mechanistic plausibility for the potential effectiveness” 21/
https://www.who.int/influenza/publications/public_health_measures/publication/en/
Guidance From UK Govt
"It is important to know that the evidence of the benefit of using a face mask covering to protect others is weak and the effect is likely to be small" 22/
https://surreyppe.co.uk/6-1-face-coverings-gov-advice-from-gov-uk/
"It is important to know that the evidence of the benefit of using a face mask covering to protect others is weak and the effect is likely to be small" 22/
https://surreyppe.co.uk/6-1-face-coverings-gov-advice-from-gov-uk/
This is not an exhaustive list. Nor does it cover results of country/state/county data vs mask/shutdown actions, virtually all lack significant correlation.
I think there is a basis for mechanistic benefit from masks, but it doesn't translate to clear benefit in spread. 23/end
I think there is a basis for mechanistic benefit from masks, but it doesn't translate to clear benefit in spread. 23/end
~1918 An Experimental Study of the Efficacy of Gauze Face Masks
“Masks have not been proved efficient enough to warrant compulsory application for the checking of epidemics” 24/
https://ajph.aphapublications.org/doi/pdfplus/10.2105/AJPH.10.1.34
“Masks have not been proved efficient enough to warrant compulsory application for the checking of epidemics” 24/
https://ajph.aphapublications.org/doi/pdfplus/10.2105/AJPH.10.1.34
1919 Influenza, a study of measures adopted for the control of the epidemic
"indicate conclusively that the compulsory wearing of masks does not affect the progress of the epidemic" 25/
https://catalog.hathitrust.org/Record/011933637
"indicate conclusively that the compulsory wearing of masks does not affect the progress of the epidemic" 25/
https://catalog.hathitrust.org/Record/011933637
2009 Use of surgical face masks to reduce incidence of common cold among health care workers in Japan: a RCT
"has not been demonstrated to provide benefit in terms of cold symptoms or getting colds"
“more likely to experience headache” 26/
https://pubmed.ncbi.nlm.nih.gov/19216002/
"has not been demonstrated to provide benefit in terms of cold symptoms or getting colds"
“more likely to experience headache” 26/
https://pubmed.ncbi.nlm.nih.gov/19216002/
2020 Community and Close Contact Exposures Associated with COVID-19 Among Symptomatic Adults ≥18 Years in 11 Outpatient Health Care Facilities
The extent of face mask use didn’t seem to have any impact. 27/
https://www.cdc.gov/mmwr/volumes/69/wr/mm6936a5.htm
The extent of face mask use didn’t seem to have any impact. 27/
https://www.cdc.gov/mmwr/volumes/69/wr/mm6936a5.htm
1981 Is a mask necessary in the operating theatre?
"wearing of a mask has very little relevance to the wellbeing of patients...and it is a standard practice that could be abandoned" 28/
"wearing of a mask has very little relevance to the wellbeing of patients...and it is a standard practice that could be abandoned" 28/
2020 Effectiveness of Adding a Mask Recommendation to Other Public Health Measures to Prevent SARS-CoV-2 Infection in Danish Mask Wearers
“recommendation to wear a surgical mask...did not reduce...incident SARS-CoV-2 infection compared with no mask” 29/
https://www.acpjournals.org/doi/10.7326/M20-6817
“recommendation to wear a surgical mask...did not reduce...incident SARS-CoV-2 infection compared with no mask” 29/
https://www.acpjournals.org/doi/10.7326/M20-6817
2020 Decrease in Hospitalization for COVID-19 after Mask Mandates in 1083 US Counties.
“The authors have withdrawn this manuscript because there are increased rates of SARS- CoV-2 cases in the areas that we originally analyzed in this study.” 30/
https://www.medrxiv.org/content/10.1101/2020.10.21.20208728v2
“The authors have withdrawn this manuscript because there are increased rates of SARS- CoV-2 cases in the areas that we originally analyzed in this study.” 30/
https://www.medrxiv.org/content/10.1101/2020.10.21.20208728v2
2020 Physical interventions to interrupt or reduce the spread of respiratory viruses
"trials did not show a clear reduction in respiratory viral infection with the use of medical/surgical masks during seasonal influenza." 31/
https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD006207.pub5/full
"trials did not show a clear reduction in respiratory viral infection with the use of medical/surgical masks during seasonal influenza." 31/
https://www.cochranelibrary.com/cdsr/doi/10.1002/14651858.CD006207.pub5/full
