Thread by @janeqiuchina

A thread on why wearing a face mask can save lives. Masks must be prioritised for healthcare workers, so use them rationally. Wear a mask when go out. You don’t have to be sick to do that. Don’t shun people who do wear them. #covid19 By @zeynep (NYT-1/14) nyti.ms/2x2naQu

“As evidence suggests COVID-19 could be transmitted before symptom onset, community transmission might be reduced if everyone, including people who have been infected but are asymptomatic and contagious, wear face masks.” By @bencowling88 @TheLancet (1/11)
thelancet.com/journals/lanre…

The big mistake in US and Europe is that people aren’t wearing masks. This virus is transmitted by droplets and close contact. When you speak, there are always droplets coming out of your mouth, so you've got to wear a mask. @sciencecohen @ScienceMagazine
sciencemag.org/news/2020/03/n…

“Many health experts, no doubt motivated by the sensible and urgent aim of preserving the remaining masks for health care workers, started telling people that they didn’t need masks or that they wouldn’t know how to wear them.” (NYT-2/14)

Many health experts “told the public simultaneously that masks weren’t necessary for protecting the general public and that health care workers needed the dwindling supply. This contradiction confuses an ordinary listener.” (NYT-3/14)

The public was told that ordinary people didn’t need masks, and that masks, especially medical-grade respirator masks (eg N95 masks), needed proper fitting and that ordinary people without such fitting wouldn’t benefit. "This message was also deeply counterproductive." (NYT-4/14)

“Many people also wash their hands wrong, but we don’t respond to that by telling them not to bother. Instead, we provide instructions; we post signs in bathrooms … Telling people they can’t possibly figure out how to wear a mask properly isn’t a winning message.” (NYT-5/14)

“Of course masks work — maybe not perfectly and not all to the same degree, but they provide some protection. Their use has always been advised as part of the standard response to being around infected people, especially for people who may be vulnerable.” (NYT-6/14)

“It is of course true that masks don’t work perfectly, that they don’t replace hand-washing and social distancing, and that they work better if they fit properly.” (NYT-7/14)

“And of course, surgical masks (the disposable type that surgeons wear) don’t filter out small viral particles the way medical-grade respirator masks rated N95 and above do. “However, even surgical masks protect a bit more than not wearing masks at all.” (NYT-8/14)

@WHO and @CDCgov “told the public to wear masks if they were sick. However, there is increasing evidence of asymptomatic transmission, especially through younger people who have milder cases and don’t know they are sick but are still infectious.” (NYT-9/14)

Since @WHO and @CDCgov “do say that masks lessen the chances that infected people will infect others, then everyone should use masks. If the public is told that only the sick people are to wear masks, then those who do wear them will be stigmatized." (NYT-10/14)

“Hong Kong health officials credit universal mask wearing as part of the solution [along with social distancing] and recommend universal mask wearing. In fact, Taiwan responded to the coronavirus by immediately ramping up mask production.” (NYT-11/14)

“Providing top-down guidance with such obvious contradictions backfires exactly because lack of trust is what fuels hoarding and misinformation.” (NYT-12/14)

“Given that there is indeed a mask shortage and that medical workers absolutely do need these masks more, what should the authorities have said? The full painful truth.” (NYT-13/14)

“Research shows that during disasters, people can show strikingly altruistic behaviour, but interventions by authorities can backfire if they fuel mistrust or treat the public as an adversary rather than people who will step up if treated with respect.” (NYT-14/14)

“The US Surgeon General advised against buying masks for use by healthy people. One important reason to discourage widespread use of face masks is to preserve limited supplies for professional use in health-care settings.” (Lancet-2/11)

“Universal face mask use in the community has also been discouraged with the argument that face masks provide no effective protection against coronavirus infection.” (Lancet-3/11)

“Face masks are widely used by medical workers as part of droplet precautions when caring for patients with respiratory infections. It would be reasonable to suggest vulnerable individuals...use surgical face masks rationally when exposed to high-risk areas.” (Lancet-4/11)

“Health authorities should optimise face mask distribution to prioritise the needs of frontline health-care workers and the most vulnerable populations in communities who are more susceptible to infection and mortality if infected.” (Lancet-5/11)

“The contrast between face mask use as hygienic practice (ie, in many Asian countries) or as something only people who are unwell do (ie, in European and N American) has induced stigmatisation and racial aggravations, for which further public education is needed.” (Lancet-6/11)

“It is time for governments and public health agencies to make rational recommendations on appropriate face mask use to complement their recommendations on other preventive measures, such as hand hygiene.” (Lancet-7/11)

“Perhaps [@WHO] would also be rational to recommend that people in quarantine wear face masks if they need to leave home for any reason, to prevent potential asymptomatic or presymptomatic transmission.” (Lancet-8/11)

“Vulnerable populations, such as older adults and those with underlying medical conditions, should wear face masks if available.” (Lancet-9/11)

“Universal use of face masks could be considered if supplies permit.” This would prevent discrimination of individuals who wear masks when unwell because everybody is wearing a mask. (Lancet-10/11)

“Urgent research on the duration of protection of face masks, the measures to prolong life of disposable masks, and the invention on reusable masks should be encouraged.” (Lancet-11a/11)

“Taiwan had the foresight to create a large stockpile of face masks; other countries or regions might now consider this as part of future pandemic plans.” (Lancet-11b/11)

More Americans should probably wear masks for protection. Protecting yourself and protecting the others. There is no shame in wearing a mask. And it's not too late yet. Wear it if you have one. Wear an improvised one if you don't. By @KnvulS @NYTimes (1/7)
nytimes.com/2020/03/27/hea…

Wearing face masks is paramount to stoping the chain of virus spread. Several studies have shown that nearly half of infected individuals have mild or no symptoms but can be highly infectious. You wouldn't know when you are right next to them. Wear a mask. ow.ly/I1xQ30qt9i0

A systematic review of interventions used during 2003 SARS found that wearing a mask was 68% effective in stopping virus transmission. Combining all measures—masks, hand-washing, gloves and a protective gown—increased the intervention effectiveness to 91%. (2/7)

“As the coronavirus pandemic rages on, experts have started to question official guidance about whether ordinary, healthy people should protect themselves with a regular surgical mask, or even a scarf.” (3/7)

. @WHO and @CDCgov "continue to state that masks don’t necessarily protect healthy individuals from getting infected as they go about their daily lives.” (4/7)

“And healthy individuals, especially those with essential jobs who cannot avoid public transportation or close interaction with others, may need to start wearing masks more regularly.” (5/7)

“There is very little data showing that flat surgical masks, in particular, have a protective effect for the general public.” => But there is difference between absence of evidence and evidence of absence. (6/7)

“Masks work by stopping infected droplets spewing from the wearer’s nose or mouth,rather than stopping the acquisition of virus from others.”Not true:face masks are widely used by medical workers to prevent being infected when caring for patients with respiratory infections (7/7)

Wearing a mask was 68% effective in stopping virus transmission during SARS. It’s critically important to use multiple strategies—masks, hand-washing and social distancing—to reduce the probability of being infected #covid19 @KellyServick @ScienceMagazine
sciencemag.org/news/2020/03/w…

“The US Surgeon General advised against buying masks for use by healthy people. One important reason to discourage widespread use of face masks is to preserve limited supplies for professional use in health-care settings.” (Lancet-2/11)

“Universal face mask use in the community has also been discouraged with the argument that face masks provide no effective protection against coronavirus infection.” (Lancet-3/11)

“Face masks are widely used by medical workers as part of droplet precautions when caring for patients with respiratory infections. It would be reasonable to suggest vulnerable individuals...use surgical face masks rationally when exposed to high-risk areas.” (Lancet-4/11)

“Health authorities should optimise face mask distribution to prioritise the needs of frontline health-care workers and the most vulnerable populations in communities who are more susceptible to infection and mortality if infected.” (Lancet-5/11)

“The contrast between face mask use as hygienic practice (ie, in many Asian countries) or as something only people who are unwell do (ie, in European and N American) has induced stigmatisation and racial aggravations, for which further public education is needed.” (Lancet-6/11)

“It is time for governments and public health agencies to make rational recommendations on appropriate face mask use to complement their recommendations on other preventive measures, such as hand hygiene.” (Lancet-7/11)

“Perhaps [@WHO] would also be rational to recommend that people in quarantine wear face masks if they need to leave home for any reason, to prevent potential asymptomatic or presymptomatic transmission.” (Lancet-8/11)

“Vulnerable populations, such as older adults and those with underlying medical conditions, should wear face masks if available.” (Lancet-9/11)

“Universal use of face masks could be considered if supplies permit.” This would prevent discrimination of individuals who wear masks when unwell because everybody is wearing a mask. (Lancet-10/11)

“Urgent research on the duration of protection of face masks, the measures to prolong life of disposable masks, and the invention on reusable masks should be encouraged.” (Lancet-11a/11)

“Taiwan had the foresight to create a large stockpile of face masks; other countries or regions might now consider this as part of future pandemic plans.” (Lancet-11b/11)

A systematic review of interventions used during 2003 SARS found that wearing a mask was 68% effective in stopping virus transmission. Combining all measures—masks, hand-washing, gloves and a protective gown—increased the intervention effectiveness to 91%. (2/7)

“As the coronavirus pandemic rages on, experts have started to question official guidance about whether ordinary, healthy people should protect themselves with a regular surgical mask, or even a scarf.” (3/7)

. @WHO and @CDCgov "continue to state that masks don’t necessarily protect healthy individuals from getting infected as they go about their daily lives.” (4/7)

“And healthy individuals, especially those with essential jobs who cannot avoid public transportation or close interaction with others, may need to start wearing masks more regularly.” (5/7)

“There is very little data showing that flat surgical masks, in particular, have a protective effect for the general public.” => There are data showing there are some effects. In any case, there is a difference between absence of evidence and evidence of absence. (6/7)

“Masks work by stopping infected droplets spewing from the wearer’s nose or mouth,rather than stopping the acquisition of virus from others.”Not true:face masks are widely used by medical workers to prevent being infected when caring for patients with respiratory infections (7/7)

I’m aware of the issue of hoarding. But many people I know in UK and US (including my sister in New Jersey) have masks but are not wearing them because: 1) they were told they wouldn’t work; 2) they were afraid of being shunned; and 3) nobody else was wearing them anyway (1/6)

It’s about treating the public like adults. Authorities just can’t tell the public wearing masks is not going to benefit them from catching a highly infectious respiratory disease when it is. We know the main transmission route is airborne droplets emitted from the throat. (2/6)

The question is: can mask wearing be beneficial? The question is *not*: what shall we tell the public to prevent them from hoarding masks? (3/6)

So what should the authorities have told the public? Perhaps: (1) Wearing a mask would be desirable, but we don't have enough to go around; (2) We have to prioritise healthcare workers and this is why; (3) We are trying our best to manufacture and import more… (4/6)

…(4) So wear a mask if you have one, make one if you don't, and don't hoard by any means. If these were the messages, there might have been an earlier and a stronger drive to ramp up production and importation of N95 and surgical masks. (5/6)

…There could have been strategies in place to channel masks to healthcare sectors. The authorities should have done all of above. Intentionally or not, misleading the public is certainly not the way to go about it. This could erode—and may well have eroded—public trust. (6/6)

Running out of masks but don't know how to make one? Check this @IgNobel solution to public health! (Spoil alert: it involves an ingenious use of bras)😃😃 By Elena Bodnar in @guardian theguardian.com/education/2010…