[Petrochemicals (OP)]

Having been a believer in the effectiveness of simple face coverings such as surgical masks against corona virus spread, I am wondering why the measures are not working . it would be easy to blame the pub and club crawlers for this, but in areas of the world like Slovakia that used face coverings for so long they seem to have lost effectiveness . In France face masks are required indoor and out yet infections are increacing.

[alancalverd]

Masks (particularly surgical masks) are not 100% efficient. The best close-fitting masks that are tolerable for civilian use, are about 97% efficient at trapping 0.3 micron particles but the COVID virus is smaller. A loose surgical mask will stop you spitting on your victim but won't trap much more than 50% of the incoming aerosol from your infectious best friend, and very few people even bother to wear those properly. The chief benefit of "social" masks is to encourage everyone else to wear them so they don't project their exhalate so far.

Parachutes and seat belts fail occasionally, but not wearing them can be 100% fatal.

The reason the numbers are rising is because that's what viruses do. One carrier in a household is almost certain to infect all the others eventually unless they all wear space suits, so once you have infected more than 5% of the population you will probably accelerate to 50%.

[set fair]

I think it's because not enough people wear them. On another forum flat dwellers reported virtually nobody wears them in communal areas. Slovakia dropped manditory masks at the end of may. Like almost all measures in the UK, mask wearing is widely ignored, social distancing in supermarkets similarly ignored.

We aren't very good at complying:- from a meta study

Only 48.9% of participants identified key symptoms ofCOVID-19.

Self-reported adherence to test, trace and isolate behaviours was low
self-isolation 18.2%
requesting an antigen test 11.9%
intention to share details of close contacts 76.1%
quarantining 10.9%

By contrast, intention to adhere to protective measures was much higher. Non-adherence was associated with: men, younger age groups, having a dependent child in the household, lowersocio-economic grade, greater hardship during the pandemic, and working in a key sector.

https://www.medrxiv.org/content/10.1101/2020.09.15.20191957v1.full.pdf

[chris]

As Alan says, the vast majority - 70-90% - of cases are transmitted among households. So once you get one case, you get the rest of the household for free.

People don't wear masks at home, and I cannot see anyone realistically entertaining that prospect in the near future.

[Petrochemicals (OP)]

Well with France going into lockdown it can pretty much ruled that they do not work to reduce infection rates, France has had outdoor and indoor masks since August.

[alancalverd]

What would have been the infection rate without masks?

Fact is that, as I've said many times before, a surgical mask is about 50% effective at trapping incoming virus, and a bit of cloth, even less so. The principal value of such face coverings is to limit the broadcast transmission of virus, not its reception.

So eventually everyone will receive an infective dose if they carry on a normal life with inefficient masks: it just takes longer to infect everyone. The infection rate, the number of people infected per day, can be decreased by cloth face coverings, but the total number infected will eventually saturate at the same number as without masks. That is what politicians proudly call "flattening the curve", as if it were  a solution rather than merely extending the problem.   

Postscript! I have just read a report in Physics World that a Japanese group have simulated various masks on a supercomputer and come to the obvious conclusion that woven soft materials are not effective traps for COVID virus, but a nonwoven surgical mask reduces exhalate transmission significantly.

[likehumansdo]

First of all: Masks do work against the spread of coronavirus. The mask mostly protects the people around you but is also useful to prevent getting infected yourself. So far as I can see it is strongly assumed, that the seriousness of the infection depends on how much of the virus you are exposed to. People with less exposure also have less sympoms or are even asymptomatic. We see this by comparing citys or states with similar demographics but different mask regulations.
Secondly: Another reason why infection rate is increasing, is an increase in testing. Though testing is a good measure, relying exclusively on these numbers convey a bit of a false image. The overall mortality isnt correlating with the infection rate as much as it did back in April and May.
Thirdly: A mask is only effective when it is being worn. Even if the majority wears them often, one uncareful event
 (wedding or birhday) can boost the infection rate again. Generally people all over the world do not take the issue that serious anymore. See this article for further information: (cant show link so just type: "Still Confused About Masks? Here’s the Science Behind How Face Masks Prevent Coronavirus")

[alancalverd]

So far as I can see it is strongly assumed, that the seriousness of the infection depends on how much of the virus you are exposed to.

That's pretty unusual for a viral infection. The speed with which you develop symptoms may depend on the initial dose, and the probability of infection clearly depends on the concentration, duration and frequency of exposure, but the problem with biological challenges is that the seriousness of the outcome depends as much on the susceptibility of the victim as on the degree of exposure - hence the notion of vaccination, to reduce susceptibility by priming the immune system.

The overall mortality isn't correlating with the infection rate as much as it did back in April and May.

largely because the true infection rate in the UK was unknown. The overall mortality rate among confirmed cases has remained fairly constant around 4 - 6% worldwide since the first data arrived from Wuhan.   

[Petrochemicals (OP)]

What would have been the infection rate without masks?

I do not know but the steepness of the daily infection curve ie how fast the infection is increasing per day is not as steep as before, but considering all the other measures brought in, pub closures, social distancing no holidays, its still steep enough. Masks* I THINK *would, not make any difference.

[alancalverd]

An opinion based on what expertise or evidence?

Apparently "Which" has just published the effectiveness of various simple face coverings, which varies from > 93% to < 0.3%  transmission of 0.3 micron particles. Some so-called masks are indeed merely cosmetic inconveniences, but a reduction of viral intake by 99.7% could save your life. 

[Bored chemist]

Masks* I THINK *would, not make any difference.

It depends on the mask.
But a good one certainly does make a difference, regardless of what you "think".

[set fair]

Another reason why infection rate is increasing, is an increase in testing.

The uncertainty principle? 

[evan_au]

The following study shows that masks are effective at "flattening the curve":
A study in the USA compared 5 counties, 2 of which introduced mandatory masks in public areas.
- Over the 15 week period, cases of infection increased in all counties
- In the 3 weeks before masks were made mandatory, all 5 counties had similar growth
- After 2 counties made masks mandatory, the growth in cases was significantly lower in those 2 counties (M+) than the 3 which did not require masks (M-)

See the study on a pre-print archive: https://www.medrxiv.org/content/10.1101/2020.10.28.20221705v1

Of course, masks are even more effective when used in conjunction with other measures like social distancing or curfews (or, if all else fails, a lockdown)...

[Petrochemicals (OP)]

The following study shows that masks are effective at "flattening the curve":
A study in the USA compared 5 counties, 2 of which introduced mandatory masks in public areas.
- Over the 15 week period, cases of infection increased in all counties
- In the 3 weeks before masks were made mandatory, all 5 counties had similar growth
- After 2 counties made masks mandatory, the growth in cases was significantly lower in those 2 counties (M+) than the 3 which did not require masks (M-)

See the study on a pre-print archive: https://www.medrxiv.org/content/10.1101/2020.10.28.20221705v1

Of course, masks are even more effective when used in conjunction with other measures like social distancing or curfews (or, if all else fails, a lockdown)...

I find this highly dubious Alan, these are 5 neighbouring areas in a small region in what one can assume is constant intermingled populace.

This ecological study evaluated the effects of a public mask mandate on the daily cumulative
case growth of COVID-19 infections among five neighboring counties within the metropolitan
statistical area of Saint Louis, Missouri: City of St. Louis, St. Louis County, Jefferson County,
Saint Charles County, and Franklin County. The study period included a three-week period prior

the mask wearing is not borne out in places like sweden versus UK cases since the start of october. Outside mask wearing is also not effective as seen in France versus UK cases in the October period.

https://en.m.wikipedia.org/wiki/Greater_St._Louis#/media/File%3ASt._Louis_MSA.svg

The areas are a mix of super urban, urban, sub-urban areas

[alancalverd]

I find this highly dubious Alan, these are 5 neighbouring areas in a small region in what one can assume is constant intermingled populace.

Quite right. If the experts disagree with you, ignore them. That's why we don't allow people with strong opinions and no knowledge onto the flight deck. But politics is different.

And the excess death rate per 100,000 in Sweden is pretty much the same as the UK, despite having a younger population and a much lower population density.

[Bored chemist]

If the experts disagree with you, ignore them.

For reasons of repetitive antagonism, this user is currently not responding to messages from;
BoredChemist

Just sayin'

[Slickscientist]

Hi,
The reason why face masks might not be effective in curbing the spread of COVID-19 is because people make them unusable or do not use them properly. Firstly, people touch the front of their masks which might contaminate them. Secondly, some people do not make them tight enough or don't cover their nose. The whole point of a mask is to protect other people from droplets when you sneeze or cough. (some people also use it to conceal their smelly breath...)
Anyway, if you don't cover your nose or make the mask lose, you are exposing the world to your saliva drops and your fish breath . Also, if your mask gets damp, it could become useless.
From Slickscientist

[Slickscientist]

People need to be educated on how to use their mask properly and dispose of them effectively; abandoned masks might contaminate a surface, which will then infect other people.

[Petrochemicals (OP)]

I find this highly dubious Alan, these are 5 neighbouring areas in a small region in what one can assume is constant intermingled populace.

Quite right. If the experts disagree with you, ignore them. That's why we don't allow people with strong opinions and no knowledge onto the flight deck. But politics is different.
.

Spit it out Alan, don't rat around the flight deck. You mean Trump is right?

[Petrochemicals (OP)]

And the excess death rate per 100,000 in Sweden is pretty much the same as the UK, despite having a younger population and a much lower population density.

Which  hole did you pull this from Alan, the swedes rank well  above the uk, but they do have healthier life stiles.

And the excess death rate per 100,000 in Sweden is pretty much the same as the UK, despite having a younger population and a much lower population density.

The density around Stockholm is also pretty high and other areas. Like any mountainous region any flat ground is at a premium like that in Japan.

https://en.m.wikipedia.org/wiki/List_of_metropolitan_areas_in_Sweden#Metropolitan_Stockholm