How often does a face mask stop a virus?

[Goonshow]

I'm curious about this. It now appears to be widely accepted that a face mask helps stop a virus spreading. But how often does a single mask do the job and save a single infection?

I think it happens rarely. I don't think masks stop the virus much, if at all, and I find the blind acceptance that they do puzzling.

My initial guess is that a mask worn by someone each day will stop transmission of the virus less than once a year.

Anyone else care to give their thoughts?

For example, does anyone believe, after giving it 5 minutes' thought, that your own mask is stopping the virus every week?

What are you talking about? My mask has never stopped me spreading the virus because I have not had Covid.

There are only 3 variables.

Err..no. Variables include whether the wearer has the virus, the wearer’s viral load, the mask composition, the mask fit, whether the wearer coughs, the ventilation, temperature and humidity, proximity to other people, the number of interactions with other people, the other people’s mask composition and fit...

@museumum

My mask hasn’t stopped me spreading the virus because I’ve not had the virus (at least I got a negative antibody test and I’ve never had symptoms). Just like my seatbelt has never saved my life because I’ve never had a mid to high speed crash.

But one day I might get symptoms and a positive test and if so I’ll be glad I was wearing a mask in the two days before symptoms which is when you are infectious.

Exactly.

Lol you're right OP, I'm not sure why we bother. I'll just stop wearing it at work, I'm sure my patients will be fine with that

At the same time, might as well stop wearing a seatbelt in the car, not sure why I bother it hasn't prevented anything yet

For example, does anyone believe, after giving it 5 minutes' thought, that your own mask is stopping the virus every week?

No, because I don’t have covid every week. My seatbelt doesn’t stop me dying every week, nor does my bike helmet. I still use them, because I don’t know when I might have asymptomatic/presymptomatic covid, or when I might have a road accident.

*patronus! Knew I hadn’t spelt it right.

I would say for the general public, next to never. For medics and those who know how to fit, change, wear them properly - more often.
On the whole they're pointless from how I see people wearing them (and to be fair myself too - I fiddle like crazy no matter how hard I try not to)

Here we go again yet another perpetual mask thread after a year and millions impacted globally.

Masks (clean and properly fitted) are better than nothing but being away from close proximity from non constantly and accurately tested potential human vectors is best but still not guaranteed protection!

Nobody likes to wears masks apart from surgeons, scientists and construction workers in extra hazardous controlled conditions. However we should all keep them on along with a strict not superficial combination of all other proven risk mitigation measures to help save the planet and so more quickly get us all out of lockdown and ultimately containment of the pandemic.

The only exemption is to stay away from others in your own bio secure bubble.

I’ve been caring for covid patients every week since the start, just in a normal surgical mask with gloves, hand washing and gel. Haven’t caught covid. I know this isn’t measurable in a large scale, but I’m pretty sure it’s saved me so far.

We have been asked to wear masks because it is then a visible reminder of the current situation

If we weren't wearing masks it would feel much less of a situation. It's a visual reminder every time you step out the front door

This thread is inadvertently great.

You’re right OP.

I’ve never had covid so my mask has never stopped me spreading covid even once, let alone every day, so obviously it’s pointless and I’ll be burning it later.

Thanks for opening my eyes 😂

I think they probably provide some protection in an environment like a supermarket where you move around and shouldn't be too close to anyone.

Unfortunately even a medical grade mask and distancing didn't stop my DH catching it (and passing it on to me) in a work environment where contact (although at 2m+ was more prolonged.

DH works on a military base and despite masks, hand washing and distancing, half the staff and recruits have Covid.

I keep a mask in my pocket for when going into shops but I don’t really think they work. I wear one to save any hassle.

[quote ShouldHaveCouldHaveWouldHave]@tommika Surely that’s only for men? If I wet myself it’s probs just gonna go down my own legs.[/quote]
Quite a bit of thread deviation.....
But have you seen the state of toilets used by men?

The different equipment between men and women is only part of the equation. The ability to point doesn’t mean a man isn’t going to pee in every direction (and on himself).
Control is needed - with bladder control, muscle control and with a bit of practice you could pee where you wanted (within reason)

Jennie Harries has clearly never set foot in a classroom. Just position the children so they are facing forwards... Right so we force our 5 and 6 year olds to sit at desks all day when they are clearly not ready developmentally. Cue disruption, restlessness and oppositional behaviour. There is no benefit to sitting like this as, actually 5 and 6 year olds TURN THEIR HEADS to look at each other, chat etc

I'm a year 1 teacher.

@Goonshow

I'm curious about this. It now appears to be widely accepted that a face mask helps stop a virus spreading. But how often does a single mask do the job and save a single infection?

I think it happens rarely. I don't think masks stop the virus much, if at all, and I find the blind acceptance that they do puzzling.

My initial guess is that a mask worn by someone each day will stop transmission of the virus less than once a year.

Anyone else care to give their thoughts?

Which is fine but it's a guess based on nothing at all. How about guessing for us how much steel is needed to hold up a given size suspension bridge and we can use your figures for that next time.

I find it very hard to believe they do anything when we have had a second wave bigger than the first since we had to start wearing them. And now we are being advised to wear 2 masks. What next? 3? 4? 10?

I think they might be better IF other measures were adhered to but you see people not socially distancing if they are wearing one, eg when you see sports events on TV.

@AntiHop

If masks don't work, why do surgeons and dentists wear them?

They wear surgical masks ie PPE, not a cloth or cheap paper face covering.

^
RedcurrantPuff
AntiHop
If masks don't work, why do surgeons and dentists wear them?
They wear surgical masks ie PPE, not a cloth or cheap paper face covering.
^

And they use fresh PPE, wash their hands, disinfect, etc to protect themselves and to prevent them picking up something to pass on to the next person

A mask is one of the measures

^museumum
My mask hasn’t stopped me spreading the virus because I’ve not had the virus (at least I got a negative antibody test and I’ve never had symptoms).
Just like my seatbelt has never saved my life because I’ve never had a mid to high speed crash.

But one day I might get symptoms and a positive test and if so I’ll be glad I was wearing a mask in the two days before symptoms which is when you are infectious.

^

I have had a car crash at a decent speed - 60mph area, but with a junction where there are often accidents. (When asked by the police I estimated my speed at >50 and something less than 60 as I would drop off the accelerator there)
A car drove straight across, and I left skid marks about a car length then hit the car - I still hit with enough force that the other car was lifted up slightly and may have flipped except for the car opposite them.
(My big car vs there little one)

My seatbelt actually injured me - broken ribs, bruised lung etc - many years later I still sometimes have limited breathing, and as part of a whole range of checkups looking into something else my lung still showed up on an X-ray.
So my seatbelt that was supposed to protect me has damaged me

Of the thousands of times I’ve driven past that junction, and dozens of times I’ve seen other accidents I could have not worn my seatbelt and been fine. But the one time I really needed it I didn’t smash my head into the steering wheel or windscreen

Hahaha haha ahahah! Wtf is this based in

My initial guess is that a mask worn by someone each day will stop transmission of the virus less than once a year.

It's just a random fucking plucked out of the air made up statistic. It's like me saying I think that wearing a seat belt only reduces injuries in 5 crashes a year. It's not based on anything.

Are you ok? Do yuu understand science?

The proper way to do this is calculate Number Needed to Treat, which could be for Every 1000 people who wore facemasks on regular basis, how many covid cases were prevented, etc.

And even then you'd want to define is it a surgical mask or 2x cloth, and ideally standardise for every 200 hours worn per year, something like that.

I'm willing to bet the NNT is astonishingly small in casual settings like shops and outside clinics and care homes, like 2 cases prevented per million hours of use. But also depends on wider prevalence. If everyone you meet in the shops has covid, that changes the math.

One reason mask-wearing is still so contentious is no one can show in an unbiased clear way that it adds a lot after other social distancing measures. Maybe a 15% reduction in risk. At best. Gabriel Leung has tweeted some on this.

I honestly don't think masks do much at all. But, if someone that is asymptomatic (or has symptoms but refuses to isolate) then it will help a little bit to stop the spread. I imagine there are lots of people that can't isolate because they can't afford to, or, think it's just a cold, so at least it is something.

This must be the most idiotic thread I've ever read on mumsnet and I've been around for 7 years.
Sorry, no offense to anyone, I just can't believe what I'm reading

Round-up of the still extremely poor evidence for effectiveness: swprs.org/face-masks-evidence/