Discussion
Started 9th Apr, 2020
  • Tung Wah Eastern Hospital

What's your point towards facemask usage under COVID-19?

People around the media are discussing the usage of facemask under COVID-19. ANd many evidence are available, yet no definite conclusion.
I have just gone through this study
Effectiveness of Surgical and Cotton Masks in Blocking SARS–CoV-2: A Controlled Comparison in 4 Patients
Ann Intern Med. 2020.
DOI: 10.7326/M20-1342
What do you think?

Most recent answer

2nd Oct, 2020
Sunny Chi Lik Au
Tung Wah Eastern Hospital
1 Recommendation

All replies (78)

9th Apr, 2020
Balkeas A Jwad
Al-Furat Al-Awsat Technical University
Is good for people in direct contact with patients
2 Recommendations
9th Apr, 2020
Jorge Andrés Sánchez-Duque
Universidad Tecnológica de Pereira
An excellent manuscript that guides us on your question is the following.
2 Recommendations
9th Apr, 2020
Monika Klimek-Tulwin
Medical University of Lublin
There are some evidence support the wearing of masks during illness to protect others, so that may help to reduce transmission. The virus is transmitted mostly throughout droplets during coughing or sneezing, and a mask will protect you from this.
Here you can find an interesting article with nice graphs and evidence:
2 Recommendations
10th Apr, 2020
Samir Rafla
Alexandria University
Sure, face mask protects droplets from patients when they cough from falling directly on my face. The mask after finishing my confrontation with patients should be throne.
For stronger protection, doctors should cover their eyes. Doctors should wash their hands before touching their face, nose, eye. One other important benefit of face mask, is that I myself do not transmit infection to others if I am carrier to the virus. We all know that many persons can be carriers without symptoms; it is reported that 50% can be carriers and show positive lab test to Corona without themselves have any signs; even more they transmitted infection to their parents and parents died without the young man who was carrier did not show signs.
Samir Rafla, professor of cardiology, Alexandria University
2 Recommendations
Deleted profile
It is an essential, Taiwan is controlling the disease by obligatory face mask
2 Recommendations
10th Apr, 2020
Mostafa Rashdan
Aswan University
Somtimes you would not know that you are sick, it is good to protect other people. So if everybody wears a mask then everybody is protected. For sure the protection is not 100% as the virus is much smalker than the holes in the mask but high percentage of protection is acheived.
3 Recommendations
10th Apr, 2020
Sunny Chi Lik Au
Tung Wah Eastern Hospital
What about the standard and material of facemask?
Does paper, cotton, cloth ... matters?
2 Recommendations
10th Apr, 2020
Sunny Chi Lik Au
Tung Wah Eastern Hospital
Using face masks in the community - Reducing COVID-19 transmission from potentially asymptomatic or pre-symptomatic people through the use of face masks. Stockholm: ECDC; 2020 Apr 8.
3 Recommendations
10th Apr, 2020
Rajkumar Rajendram
King Saud bin Abdulaziz University for Health Sciences
To control the Covid-19 pandemic effectively, healthcare professionals and the public must hear and accept difficult truths. America has failed to do this; so the virus spreads unchecked.
Transmission of the virus can not be stopped it can only be delayed to allow healthcare systems to cope with the increased demand on services. So please preserve respirator face masks for healthcare professionals who must care for patients infected with SARS-CoV-2.
Unfortunately, rather than being honest; authorities have repeatedly changed advice about the need to wear face masks. As a result, healthcare professionals and the public can no longer trust what is being said. The mistrust has been fuelled by conflicting messages for healthcare professionals and the general public.
In the current situation the only safe thing for anyone to do is to try to wear face masks that provide the best protection. The real difficulty is that the best medical grade respirator face masks are in extremely short supply. Healthcare professionals, putting their lives on the line, need these masks to protect themselves from their infected patients.
Up to 25% of healthcare professionals in the UK are either off work due to sickness or because of suspected exposure. Excess deaths occur when healthcare systems can not care for patients who need treatment. The more healthcare workers who go off sick, the less care sick patients can receive.
The public can be protected by social distancing. As an intensivist I do not have this option, I must get very near to patients to look after them. I will be honest; respirator face masks do protect people from transmission of Covid-19. Cloth face masks are unlikely to protect uninfected people but are likely to reduce spread of virus from those infected with SARS-CoV-2. Not going near patients with Covid-19 is much more effective.
I therefore ask the public to fully engage with social distancing and preserve the medical grade face masks for healthcare professionals who do not have this option.
2 Recommendations
10th Apr, 2020
Samir Rafla
Alexandria University
Sure, face mask protects droplets from patients when they cough from falling directly on my face. The mask after finishing my confrontation with patients should be thrown. For stronger protection, doctors should cover their eyes. Doctors should wash their hands before touching their face, nose, eye. One other important benefit of face mask is that I myself do not transmit the infection to others if I am carrier to the virus. We all know that many persons can be carriers without symptoms; it is reported that 50% can be carriers and show positive lab test to Corona without themselves have any signs; even more, they transmitted infection to their parents and parents died without the young man who was carrier did not show signs. Samir Rafla, professor of cardiology, Alexandria University
2 Recommendations
10th Apr, 2020
Cedric Yoshimoto
Doctors Without Borders
Regarding Taiwan, it actually rapidly enacted 124 measures to control this outbreak, not only facemasks:
On the other hand, Singapore initially had excellent control of Covid-19, and it specifically did NOT advise the use of facemasks by the general population:
I would say that the question of facemasks is very complicated, and not yet resolved.
2 Recommendations
10th Apr, 2020
Alexander Scott English
Shanghai International Studies University
Face masks work! Masks do 2 things. First, the reduce the R0 (the rate of transmissibility..for ex if 1 person infects 5 people, R0 is 5) because people with germs keep them to themselves rather than spreading them to others and droplets on surfaces. Must get R0 below 1 to slow it down. Second, masks lower the inoculum. If you do get infected, you want to start with a low inoculum. The inoculum is the viral dose that infects a person. If two people are wearing a mask and one person coughs, the amount of virus that escapes the first mask and enters the second mask will be far smaller than if a sick person coughs into another person’s mouth directly. Once the virus enters the body, it replicates. If the initial dose is small, the number replicates from a smaller number giving the body a chance to defend and possibly allowing the person a more mild case. If the inoculum is in the millions of particles, it replicates from a bigger start and causes far worse outcome as the body can’t defend the viral invasion load. If we all wear masks, we can get our arms around this thing.
3 Recommendations
11th Apr, 2020
Mahendra Kumar Shrivas
Central University of Nicaragua
Below are good materials to create three layers Cloth Face Mask at Home:-
Inner layer :- 100% Cotton t-shirt
Middle layer:- Dish Towel
Outer layer:- 100% Cotton t-shirt.
OR
Inner layer :- 100% Cotton t-shirt
Middle layer:- Pillow Case
Outer layer:- 100% Cotton t-shirt
Note:- N95 or Triple layer medical mask is best for medical professional or for family members who are taking care of infected persons.
2 Recommendations
11th Apr, 2020
Cedric Yoshimoto
Doctors Without Borders
Thanks to everybody for their interest, concern, and contributions.
Alexander Scott English is correct that reducing R0 below 1 is the desirable measure of controlling the propagation of the virus. May I just ask, would he share with us the evidence that face masks (顺心彩票made cloth or surgical) actually reduce the R0? Sometimes the intuitively obvious result turns out to be more complicated than realized or even not to be true.
One published clinical trial of cloth masks (before Covid-19) showed that health workers wearing cloth masks had HIGHER rate of respiratory illness, influena-like illness, and laboratory-confirmed viral infection than either controls (some wearning masks, some not) and workers wearing surgical masks. (MacIntyre CR, et al. BMJ Open 2015;5:e006577. doi:10.1136/bmjopen-2014-006577) The authors speculated that the reason could involve poor filtration of cloth masks, their contamination with virus, and inadequate doffing technique..
There is some support for this hypothesis from a very small study in South Korea (ttps://annals.org/aim/fullarticle/2764367/effectiveness-surgical-cotton-masks-blocking-sars-cov-2-controlled-comparison), which showed that neither cloth nor surgical masks blocked SARS-CoV-2 during cough, and that the outer surfaces of both cotton and surgical masks were contaminated with virus.
A quick systematic review of studies (pre-Covid-19) on (mostly surgical) facemasks to protect against respiratory illness ( )
summarized that "a facemask may very slightly reduce the odds of primary infection with influenza-like illness" in certain circumstances, and that "using a mask for short periods of time by particularly vulnerable individuals during transient exposure events may be justified."
Among the caveats about this issue are the importance of contact protective measures & social distancing, protection of other mucous membranes (eyes), the type of mask material, the fit of the mask, handling of the contaminated mask after use, and the priorities for a limited supply of surgical and N-95 masks.
Sunny Chi Lik Au, you are right. There is a lot of partial information, but no simple answer.
2 Recommendations
11th Apr, 2020
Mahendra Kumar Shrivas
Central University of Nicaragua
Would I mentioned that the facemasks (顺心彩票made cloth or surgical) actually reduce the R0?
Here are some referance articles for 顺心彩票made FaceMask:-
Above blog is based on below scientific research paper:-
As mentioned above "neither cloth nor surgical masks blocked SARS-CoV-2 during cough", means most of the health workers are in danger as they're wearing 3 fold surgical mask.
Does N95 mask protect during cough?
Does N95 actually reduce the R0 below 1 or acceptable level?
1 Recommendation
11th Apr, 2020
Sunny Chi Lik Au
Tung Wah Eastern Hospital
We may take a look at this via the following paper
Association between 2019-nCoV transmission and N95 respirator use
Published:March 03, 2020
3 Recommendations
11th Apr, 2020
Sunny Chi Lik Au
Tung Wah Eastern Hospital
Some other indirect evidence on facemask usage towards COVID-19 as well:
Leung, N.H.L., Chu, D.K.W., Shiu, E.Y.C. et al. Respiratory virus shedding in exhaled breath and efficacy of face masks. Nat Med (2020).
3 Recommendations
12th Apr, 2020
Cedric Yoshimoto
Doctors Without Borders
Thank you for pointing out this study by Leung et al. That's right, they showed DECREASED shedding of various viruses through surgical masks during breathing, but they did NOT test people infected with SARS-CoV-2. In contrast, Bae et al. found that surgical & cloth masks did NOT filter out SARS-CoV-2 during coughing. Both of these studies examined the role of masks worn by sick people. I interpret this to mean that we are slowly building up a more full picture, but we are a long way from knowing the bottom line on masks (which mask under which practical conditions protects which people from this SARS-CoV-2 virus?), let alone the best combination of PPE with many other factors to control this pandemic.
The study by Wang et al. reinforces other information: N95 masks are the most effective (for protecting healthy people). I will just mention that N95 masks must be properly fit-tested to be fully protective, and should be handled as medical waste, but as we know, there are shortages in many places.
2 Recommendations
13th Apr, 2020
Stephen C Schoenbaum
The Josiah Macy Jr. Foundation
There is a Cochrane Review on effectiveness of physical barriers in respiratory viral infection by Jefferson et al. I'm uploading the Abstract.
2 Recommendations
13th Apr, 2020
Sunny Chi Lik Au
Tung Wah Eastern Hospital
Stephen is referring to below:
Physical interventions to interrupt or reduce the spread of respiratory viruses
Cochrane Systematic Review - Intervention Version published: 06 July 2011
Reference at link below:
3 Recommendations
13th Apr, 2020
Sunny Chi Lik Au
Tung Wah Eastern Hospital
Some more at
BMJ. 2009; 339: b3675.
doi: 10.1136/bmj.b3675
PMCID: PMC2749164
PMID: 19773323
Physical interventions to interrupt or reduce the spread of respiratory viruses: systematic review
3 Recommendations
13th Apr, 2020
Sunny Chi Lik Au
Tung Wah Eastern Hospital
Amd some others at BMJ. 2008 Jan 12; 336(7635): 77–80.
doi: 10.1136/bmj.39393.510347.BE
PMCID: PMC2190272
PMID: 18042961
2 Recommendations
14th Apr, 2020
Idowu Goodnews Oluwaseyi
University of the Highlands and Islands
Truth be said, from Various Theoretical studies, i am well aware that the speed of spread is what the WHO and countries are struggling to reduce. Just like i said, anyways looking at previous pandemics, this will eventually hit almost everyone in the world and of course many will survive while some will die. The aim is to reduce the speed so that the healthcare system is not overwhelmed. But then, the big problem comes again.. unlike other diseases especially looking at the Spanish flu which killed less than 40 year olds more.. there are loads of records of re-infection now (Korea and china reported 100s in the last few days)
So i suggest and think ultimately that to achieve a slow speed of transmission/spread, the world needs to apply all precautions possible.. (Face masks included). Remember that the goal is to prevent the Extinction of man!
3 Recommendations
15th Apr, 2020
Vo Dinh Vinh
HUBT
Because up to 40% of people are infected with covid 19 but have no symptoms. Therefore, it is necessary for everyone to wear the facemasks when interacting with each other. In Vietnam, we have been applying this method together with other effective solutions, so far, the number of covid 19 infections is less than 300 people, especially no patients have died.
3 Recommendations
15th Apr, 2020
Samir Rafla
Alexandria University
When to use a mask
  • If you are healthy, you only need to wear a mask if you are taking care of a person with the suspected 2019-nCoV infection.
  • Wear a mask if you are coughing or sneezing.
  • Masks are effective only when used in combination with frequent hand-cleaning with alcohol-based hand rub or soap and water.
  • If you wear a mask, then you must know how to use it and dispose of it properly.
When and how to wear medical masks to protect against coronavirus
  • Before putting on a mask, clean hands with alcohol-based hand rub or soap and water.
  • Cover mouth and nose with mask and make sure there are no gaps between your face and the mask.
  • Avoid touching the mask while using it; if you do, clean your hands with alcohol-based hand rub or soap and water.
  • Replace the mask with a new one as soon as it is damp and do not re-use single-use masks.
  • To remove the mask: remove it from behind (do not touch the front of the mask); discard immediately in a closed bin; clean hands with alcohol-based hand rub or soap and water.
Samir Morcos Rafla, MD, PhD
FACC, FESC, FHRS, member EHRA
Emeritus professor of Cardiology, Alexandria University, Egypt
01001495577
2 Recommendations
15th Apr, 2020
Stephen C Schoenbaum
The Josiah Macy Jr. Foundation
I disagree. Since a substantial percentage of infected people, estimated to be 30-40 percent, are asymptomatic or minimally symptomatic, you don't know who is shedding the virus. Those who are "suspected" are only part of the picture.
2 Recommendations
15th Apr, 2020
Rajkumar Rajendram
King Saud bin Abdulaziz University for Health Sciences
Dr Fauci gave a great interview to Lilly Singh that is available on youtube. He debunks several misconceptions. He discusses the role of facemasks.
2 Recommendations
16th Apr, 2020
Sunny Chi Lik Au
Tung Wah Eastern Hospital
Let's look at this recent publication
Face masks for the public during the covid-19 crisis. BMJ. 2020 Apr 09;369:m1435.
3 Recommendations
16th Apr, 2020
Maqsood Ali Mohammad Rafiq
NMC Healthcare LLC
Now as the COVID-19 pandemic is hitting badly ALL citizens are advised to use face mask made of cloth when outdoors or has other people around while indoors, those with upper or lower respiratory symptoms should the face mask at all times.
Dr. Maqsood Ali
MBBS, MRCGP, DTCD, FCCP
Specialist Family Medicine
2 Recommendations
16th Apr, 2020
Eugenia Yiannakopoulou
University of West Attica
There is no sufficient evidence to support the widespread use of facemask as a protective means against COVID-19 pandemic. People are not trained on the appropriate way of putting the facemask. The facemask creates a false impression of safety. In addition, the widespread of facemask could icreases the rates of non compliance to the restriction measures. Furthermore, people with respiratory symptoms either infected with COVID-19 or from some other respiratory virus could put a facemask and go out.
The facemask should be used as a protective means for patients for family people that come in touch with them.
2 Recommendations
17th Apr, 2020
Sunny Chi Lik Au
Tung Wah Eastern Hospital
Some latest publications:
Visualizing Speech-Generated Oral Fluid Droplets with Laser Light Scattering. N Engl J Med. 2020 Apr 15.
3 Recommendations
17th Apr, 2020
Sunny Chi Lik Au
Tung Wah Eastern Hospital
Effect of various decontamination procedures on disposable N95 mask integrity and SARS-CoV-2 infectivity. medRxiv. 2020 Apr.
3 Recommendations
17th Apr, 2020
Sunny Chi Lik Au
Tung Wah Eastern Hospital
Droplets and Aerosols in the Transmission of SARS-CoV-2. N Engl J Med. 2020 Apr 15.
DOI: 10.1056/NEJMc2009324
3 Recommendations
21st Apr, 2020
Sunny Chi Lik Au
Tung Wah Eastern Hospital
Impact assessment of non-pharmaceutical interventions against coronavirus disease 2019 and influenza in Hong Kong: an observational study.
Lancet Public Health. 2020 Apr 17.
2 Recommendations
21st Apr, 2020
Saad Ahmed Ali Jadoo
Bezmialem Vakif üniversitesi
The World Health Organization has been insisting that the use of a face mask is only important for health professionals who are expected to become infected through direct contact with patients. Also, infected (confirmed) patients should use a face mask in order not to infect others. The problem now lies in unknown cases (asymptomatic cases) that unintentionally transmit the disease to others. Although most people do not know the correct way to use a face mask or how to deal with it when the face mask needs to be lifted, however, it is mandatory to use a face mask when going out,
2 Recommendations
21st Apr, 2020
Joel Aboagye Danso
University of Health and Allied Sciences
The use of face masks contributes effectively in reducing the rate of spread of covid 19, it also protects the uninfected from getting the infection. One thing about nose masks is that, they come in varieties based on the climate of every geographical region, therefore users must be careful in the type they use.
2 Recommendations
21st Apr, 2020
Joel Aboagye Danso
University of Health and Allied Sciences
The use of face masks contributes effectively in reducing the rate of spread of covid 19, it also protects the uninfected from getting the infection. One thing about nose masks is that, they come in varieties based on the climate of every geographical region, therefore users must be careful in the type they use.
2 Recommendations
22nd Apr, 2020
Krishna Kumar Govindarajan
Jawaharlal Institute of Postgraduate Medical Education & Research
Except with family inside the house, face mask would be the need of the hour to prevent acquiring /transmitting infection. Asymptomatic Covid 'carriers' create the greatest threat to the community as they transmit infection unknowingly.
2 Recommendations
23rd Apr, 2020
Sunny Chi Lik Au
Tung Wah Eastern Hospital
Other than facemask, do you find handrub useful too?
Inactivation of severe acute respiratory syndrome coronavirus 2 by WHO-recommended hand rub formulations and alcohols.
Emerg Infect Dis. 2020
2 Recommendations
Deleted profile
Look at Taiwan; there is no need to find a clue for using masks, COVID-19, as low as 500 cases. Obligatory face mask worked there.
3 Recommendations
25th Apr, 2020
Cedric Yoshimoto
Doctors Without Borders
As mentioned & referenced in a post on April 10, Taiwan enacted 124 measures including facemasks to combat Covid-19 successfully. Singapore initially had an effective response (at least for citizens, not for migrant workers) based on multiple measures, but without facemasks.
It appears to me that, in the absence of better evidence, multiple thoughtful measures may be the best response.
Although the evidence for the benefit of public use of facemasks is very thin, there is an extremely interesting study indicating that cloth facemasks (as used by the general public) can be substantially enhanced by the use of a nylon overlayer to improve the fit:
Good luck to us all.
2 Recommendations
26th Apr, 2020
Rosario Falanga
Azienda per l'Assistenza Sanitaria n. 5 "Friuli Occidentale"
For the family doctor who visits their patients I think an FFP2 (N95) mask is necessary for the population a standard surgical mask is sufficient.
2 Recommendations
27th Apr, 2020
Pabita Dhungel
Pacific University Oregon
Whether you are infected or not, wearing a mask does not do nay harm. In the amidst of this crisis and lack of appropriate number of testing unless you show any clinical symptoms, we may be carrier without showing any symptoms and so do other people we come in contact with.
Wearing a mask prevents the amount of inoculum while we are coughing decreasing the chances of infection to other people . It prevents the amount while we are coughing and also if the person we are talking to is also wearing a mask, the transmission rate will be minimum. It is technically hard to get N95 mask for general people , but wearing a surgical mask or even cotton cloth mask will also provide some sort of barrier.
3 Recommendations
30th Apr, 2020
Sunny Chi Lik Au
Tung Wah Eastern Hospital
Medical masks vs N95 respirators for preventing COVID-19 in healthcare workers: A systematic review and meta-analysis of randomized trials.
Influenza Other Respir Viruses.
3 Recommendations
30th Apr, 2020
Sunny Chi Lik Au
Tung Wah Eastern Hospital
A reality check on the use of face masks during the COVID-19 outbreak in Hong Kong.
EClinicalMedicine. 2020 Apr 24;100356.
3 Recommendations
13th Jun, 2020
David Hagen
Dare science consider contrary evidence? Rancourt reviews research on masks:
Denis Rancourt, "Masks Don’t Work: A review of science relevant to COVID-19 social policy"
See Dr. Rancourt on ResearchGate D. G. Rancourt
ResearchGate's censorship of Rancourt is discussed by Charles Rotter:
COVID Censorship at ResearchGate: Facts about Face Coverings Covered Up?
3 Recommendations
13th Jun, 2020
D. G. Rancourt
Ontario Civil Liberties Association
This is my report about RG's deplatforming of my article " Masks Don’t Work: A review of science relevant to COVID-19 social policy", after it reached 400 K reads on RG. My report has the exact email exchange, which clarifies the reasons given for the censorship: https://archive.org/details/covid-censorship-at-research-gate-2/
4 Recommendations
13th Jun, 2020
David Hagen
ResearchGate's deplatforming your article "Masks Don't Work" is modern-day #Lysenkoism driven by popular partisan coercion. It reflects science's underlying conflict between truth versus popularity biased by funding. See Robert Kuhn's expose. vis In retrospect: The Structure of Scientific Revolutions, David Kaiser, Nature volume?484,?pp164–165(2012) https://www.nature.com/articles/484164a
3 Recommendations
Deleted profile
Sooner or later researchers will figure out that COVID-19 transmission happens just in people with a specific gene that make them susceptible to the disease. Probably in people who have more Angiotensin receptors
24th Jun, 2020
Anchit Bharat
Indiana University Health
Asymptomatic spread has been postulated thus far. Although different federal and international bodies have different opinions on this, studies lean towards this fact. With this information, even though surgical masks or face coverings might have there limitations. They might reduce some spread. Not only during sneezing or coughing but also talking or breathing might spread the virus.
24th Jun, 2020
Anchit Bharat
Indiana University Health
It is very important when wearing a mask to not touch the mask itself constantly. If you want to take the mask off prefer taking it out just by the strings. Touching the mask from the outside layer and then touching your face/ nose might defeat it’s purpose.
24th Jun, 2020
D. G. Rancourt
Ontario Civil Liberties Association
OCLA has sent a 9-page letter to the?Director General? of the World Health Organization, Dr. Tedros Adhanom Ghebreyesus, asking him to retract the WHO’s recommendation advising the use of face masks in the general population to prevent COVID-19 transmission.
Please read the letter and its many references.
The letter criticizes the lack of a valid scientific basis for the WHO’s recommendation and expresses OCLA’s concerns about serious harms to individuals and societies stemming from the recommendation and from government impositions of face masks on the general public.
The letter includes statements such as:
“… the WHO cannot collect and rely on potentially biased studies to make recommendations that can have devastating effects (see below) on the lives of literally billions. Rather, the WHO must apply a stringent standards threshold, and accept only randomized controlled trials with verified outcomes. In this application, the mere fact that several such quality studies have not ever confirmed the positive effects reported in bias-susceptible reports should be a red flag.”
and
“It is an unjustified authoritarian imposition, and a fundamental indignity, to have the State impose its evaluation of risk on the individual, one which has no basis in science, and which is smaller than a multitude of risks that are both common and often created or condoned by the State.”
7th Jul, 2020
Muhammed Ashraful Alam
Ministry of Health and Family Welfare, Bangladesh
Face mask can control the spread from both symptomatic and asymptomatic cases. It should be mandatory in current context.
7th Jul, 2020
Anchit Bharat
Indiana University Health
With the current cases rising exponentially, face coverings/ masks are the best tool we have as prevention is the best policy. We do not have as robust/ effective of a treatment arsenal in present time. With such a variability of spread and disease causation, it should be made mandatory till we have an effective vaccine.
7th Jul, 2020
Shno Mustafa Ali
Kirkuk University
I agree with Terri Purvis
17th Jul, 2020
Karen Peckover
Bayshore Home Health
Interesting article by David Kyle Johnson, Ph.D., published in Psychology Today July 14, 2020 entitled “Yes, Masks Work: debunking the Pseudoscience - a reply to Denis Rancourt‘s "Masks Don’t Work” which speaks to expectation bias, confirmation bias and pseudo scientists.
29th Jul, 2020
Anton Vrdoljak
University of Mostar
I will answer with a Croatian proverb:
Better to prevent than to cure (It is more expensive to correct mistakes than to prevent them).
English equivalent: Better safe than sorry.
29th Jul, 2020
Anton Vrdoljak
University of Mostar
To
Farkhanda Ijaz
: It is difficult, but our doctors and other medical staff wearing masks and special cloths, we have to respect them and follow precautions, support others and be productive. Stay healthy!
29th Jul, 2020
Falih Al-Emara
University of Basrah
The mask is critically useful as a first-line defense against the virus. It at least helps in reducing the amount of the virus dose infection. Observation shows that people who strictly stick to wearing the mask are less subjected to the infection.
29th Jul, 2020
Colin Sokol Kuka
The University of York
Dear Sunny Chi Lik Au I believe that the mask are useless as protection equipment, exactly as the WHO said initially. However, the masks in social medias and in everyday life are a powerful message to all the humans that the virus is still around and to be careful. The mask is a big advertise on prevention.
Your feedback is highly appreciated. Best Regards. Colin
1 Recommendation
7th Aug, 2020
Mostafa Rashdan
Aswan University
I agree with Faleh Al-Emara
9th Aug, 2020
Eugenia Yiannakopoulou
University of West Attica
I also agree that there is no robust evidence on the application of the universal face masking of the public. Robust evidence is needed for the adoption of an intervention by healthy people. Face mask is an intervention that like a drug. Each intervention could have desired effects or undesired effects. If people had to wear a mask, they would have been born wearing a mask. The respiratory tract and the alimentary tract come in contact with the environment. Both respiratory and alimentary tract are equipped with protective mechanisms against the environmental pathogens. Environmental pathogens always exist. Therefore, universal masking could have undesired effects, leading to impairment of the protective mechanisms of the respiratory and alimentary tract. In other words, each intervention applied to humans should be based on the same level of investigation as that required for all the health interventions. It is not justified to adopt a health measure because it is cheap and easy to be implemented.
11th Aug, 2020
Hung Nguyen
Lynchburg College
Wearing a face mask during the novel virus to mitigate the spread of coronavirus disease 2019 is hotly contested. Americans are increasingly adopting the use of cloth face mask to slow the spread of COVID-19, and the latest science may convince even more to do so.
There were two cases studies, one from JAMA, showing that the adherence to universal masking policies reduced SARS-CoV-2 transmission within a Boston hospital system, and one from CDC's Morbidity and Mortality Weekly Report (MMWR), showing that wearing a face mask prevented the spread of infection from two hairstylists to their customers in Missouri. Reportedly the hairstylists infected with and having symptoms of COVID-19, and whose salon policy followed a local ordinance requiring cloth face covering for all employees and patrons. The investigators found that none of the stylists'139 clients or secondary contacts became ill, and all 67 clients who volunteered to be tested showed no sign of infection.
Resources:
Dr.Hung Nguyen, DMSc
1 Recommendation
15th Aug, 2020
Dragos Simandan
Brock University
I basically agree with the formulation of these twenty-three Canadian public health experts from July 2020: http://balancedresponse.ca/statement/
"COVID-19 control must be balanced with basic human rights. ?People need to be empowered to make informed choices about their own lives and the level of risk they are prepared to accept.? Universal public health measures are appropriate only when they are truly necessary, supported by strong evidence, and when there are no other alternatives".??
and
"Be clear on when the use of medical and non-medical masks is recommended.? When advice varies based on local epidemiology, provide clear evidence-based criteria for decision-making.? Any requirements for mandatory masks must be based on strong evidence with clear specification of where they are most appropriate (close quarters, congregate living settings, etc)".
The evidence regarding masks is all over the place, with plenty of studies showing ineffectiveness or very modest effect sizes in prevention: https://www.cebm.net/covid-19/masking-lack-of-evidence-with-politics/
" It would appear that despite two decades of pandemic preparedness, there is considerable uncertainty as to the value of wearing masks. For instance, high rates of infection with cloth masks could be due to harms caused by cloth masks, or benefits of medical masks. ?The numerous systematic reviews that have been recently published all include the same evidence base so unsurprisingly broadly reach the same conclusions. However, recent reviews using lower quality evidence found masks to be effective".
So in light of the above, mask mandates are illegitimate on two counts:
1. They are not supported by strong evidence;
2. They violate the criterion "COVID-19 control must be balanced with basic human rights" (see above).
There is a simple and balanced way out of this: recommend them to the public in certain crowded indoor settings, but do NOT make them mandatory. That's more than enough.
For history buffs, see also: https://archive.is/ezks2
25th Aug, 2020
Kins Yenoke
Loyola College
Face mask helps us to reduce the amount spread through nose and mouth.
25th Aug, 2020
Mostafa Rashdan
Aswan University
The problem is that people are not taking it serious, a lot of people do not use masks consistently. A lot of people are participating in social activities.
3rd Sep, 2020
Dirk Nodop
ifw Jena
It seems to me that this study was rectracted for good reasons?
10th Sep, 2020
Liviu Popa-Simil
LAAS- Los Alamos Academy of Sciences
All of you are in part right and in part wrong, because lack of understanding of micro-nano fluidics inside filters.
Yes - MASKS WORK -if they are used in the same fashion as one uses car light beams when driving: low beams when near other cars (that means MASK ON = low range for spit and other exhaling products; attenuation 14-20 dB by contamination surface and contamination volume reduction) and long beams = MASK OFF - when alone on the street.
More when new or functional masks provide about 10 dB aerosol particulate concentration reduction, that is dependent on particle magnitude - and here the devil is in details:
- Talk about influenza - is 40-60 nm entity - atenuation -1; -2 dB =almost nothing nor MREV20 can touch that!
- Talk about COVID19 powder dimensions 60-140 nm - atenuation -3 dB at maximum
- Talk about aerosol particulate or airborne watery droplets containing is a more compex talk, better read:
- there are about 3 papers on that publication that clarifies these issues - but generically micro hydraulics enter into play and makes things more complicated.
for these an average reduction factor is about 10 dB.
Therefore for the masks as you know you may count on -30 dB reduction at its maximum, but when wear as you saw - a -20 dB is what western societies can do.
Statistics show that the chances to get sick are between 1 in 25 to 1 in 100 with these masks when are used correctly - for public is about 1 in 20.(that is a kind of Russian roulette with a magazine of 20 cartridges and only 1 loaded).
To get a real protection one need a protection factor or attenuation of about -120dB and that is not easy to obtain and be easy and comfortable to wear in the same time. We have the solution, we explained to US authorities but they did not want to hear, therefore we have patented it, and will be published later - US was interested in killing grand parents - because by killing 1 US social security and medicare saves about $50 k/year for 10 years (average life after 65) $1Million may be saved. Up to now the US administration saved 160k grand parents dead x $500k = $80 Billions (still do not match the debt made by tax cuts so we need to kill more) and here comes into play Health politics, HELLTH CARE system, and all the clowns and impostors you may have seen on TV as American specialists and experts (fauci, Blix, VP, P...) talking about "constitutional rights" and freedoms, with more details in book "RAGE". Have fun, but when politics overrides science the result is as remarkable as US obtained 300 k dead in 2020 alone and counting; can't tell you about other 6M spending 2 mo to fight this pandemic and remaining with "battle scars" for the rest of their lives. The vacine, is a complex bussiness and will kill not only virus but other good proceses inside the body. so we may expect a society of Class 1 (after disease) and class 2 (after vaccine) COVIDS, similar to HIV societies.
28th Sep, 2020
Gohar Shahsuvaryan
Center of medical genetics
in my opinion and logically, since the transmission of the virus is possible, including through the mucous membrane of the eye, what is the point of wearing masks with unprotected eyes, in addition, it is extremely important which masks to wear and where.
28th Sep, 2020
Mostafa Rashdan
Aswan University
You are right but do people get infected through the eye regularly ? i mean is it the same as getting infected through the nose or the mouth.
28th Sep, 2020
Gohar Shahsuvaryan
Center of medical genetics
Who knows exactly?
28th Sep, 2020
Mostafa Rashdan
Aswan University
Actually nobody
28th Sep, 2020
Liviu Popa-Simil
LAAS- Los Alamos Academy of Sciences
gentlemen, I appreciate you are talking and get concerned, but please read and learn a little bit meanwhile, as you may get a lot of info in previous answers.
Some facts:
Virus penetrates the body all the paths with different survival probabilities:
1. Inhaling it straight inside lungs - survival probability near 100%
2. Through skin - is 100+ times smaller than pores, falls on the bottom and goes in venous blood - from there to hart, then lungs and allover - survival probability -20dB (1%)
3. Soft tissue - eye, mouth lips, nose - survival probability -10dB ( <10%)
virus has an incubation period, 3-7 days depends of path and how many penetrated inside and where; then a asymptomatic contagious period and after that symptoms appear and carrier realizes that is sick and seeks medical treatment becoming registered as infected. From here follows recovery with "battle scars" for life, or ventilator with death (1 in 35).
Masks gives 10-30 dB in individual protection meaning that one may get sick in 25 exposures (1-4%), and in reality one needs -100 dB to be safe in virus dominated environments.
Mask, face shields are effective in stopping the emitted exhalation plume to reach over 8 ft (2.5m) reducing its range at about 1 ft, and by this it adds -20dB to collectivity mutual protection finally coming with cumulative -30dB protection factor that reduces the transmission factor or multiplication rate from up to 50 down to 0.1 and that STOPS PANDEMIC propagation (in avalanche) but DO-NOT stop the disease. To stop that collateral medical and social measures are needed as:
backtracking with quarantine, vaccine, medication for sick.
Please study a little bit this answer, be familiar with medical publications, and come with reasonable scientific opinions not guts or religion based.
Good luck and stay safe!
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WHO said that many countries had the wrong strategy to deal with the COVID-19 pandemic
This is what we fear will happen and why we emphasize in our scientific publication since almost 3 months ago in a Journal indexed by Scopus with the title:
‘The Need For Consensus On The Effective Approach To Control COVID-19 Outbreak’
Preprint: Amin, Firman Zulkifli, Sari, Mila Kurnia, & Amin, Zulkifli. (2020, April 26). The need for consensus on the effective approach to control COVID-19 outbreak. Zenodo. http://doi.org/10.5281/zenodo.3766566

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