London put in emergency lockdown as U.K. fights new strain

Re:London put in emergency lockdown as U.K. fights new strain by PaulDavisThe1st on Saturday December 19, 2020 @06:58PM (#25482500)

Here's the CDC:

---------------

Data regarding the “real-world” effectiveness of community masking are limited to observational and epidemiological studies.

    * An investigation of a high-exposure event, in which 2 symptomatically ill hair stylists interacted for an average of 15 minutes with each of 139 clients during an 8-day period, found that none of the 67 clients who subsequently consented to an interview and testing developed infection. The stylists and all clients universally wore masks in the salon as required by local ordinance and company policy at the time.

    * In a study of 124 Beijing households with > 1 laboratory-confirmed case of SARS-CoV-2 infection, mask use by the index patient and family contacts before the index patient developed symptoms reduced secondary transmission within the households by 79%.

    * A retrospective case-control study from Thailand documented that, among more than 1,000 persons interviewed as part of contact tracing investigations, those who reported having always worn a mask during high-risk exposures experienced a greater than 70% reduced risk of acquiring infection compared with persons who did not wear masks under these circumstances.

    * A study of an outbreak aboard the USS Theodore Roosevelt, an environment notable for congregate living quarters and close working environments, found that use of face coverings on-board was associated with a 70% reduced risk.

    * Investigations involving infected passengers aboard flights longer than 10 hours strongly suggest that masking prevented in-flight transmissions, as demonstrated by the absence of infection developing in other passengers and crew in the 14 days following exposure.

Seven studies have confirmed the benefit of universal masking in community level analyses: in a unified hospital system, a German city, a U.S. state, a panel of 15 U.S. states and Washington, D.C. as well as both Canada and the U.S. nationally. Each analysis demonstrated that, following directives from organizational and political leadership for universal masking, new infections fell significantly. Two of these studies and an additional analysis of data from 200 countries that included the U.S. also demonstrated reductions in mortality. An economic analysis using U.S. data found that, given these effects, increasing universal masking by 15% could prevent the need for lockdowns and reduce associated losses of up to $1 trillion or about 5% of gross domestic product.

------------

Taken from: https://www.cdc.gov/coronavirus/2019-ncov/more/masking-scien...

[ Parent | on HN ]

Re:London put in emergency lockdown as U.K. fights new strain by timr on Sunday December 20, 2020 @12:15AM (#25484048)

> in a unified hospital system, a German city, a U.S. state, a panel of 15 U.S. states and Washington, D.C. as well as both Canada and the U.S. nationally. Each analysis demonstrated that, following directives from organizational and political leadership for universal masking, new infections fell significantly. Two of these studies and an additional analysis of data from 200 countries that included the U.S. also demonstrated reductions in mortality. An economic analysis using U.S. data found that, given these effects, increasing universal masking by 15% could prevent the need for lockdowns and reduce associated losses of up to $1 trillion or about 5% of gross domestic product.

All of these studies were conducted on data from the spring, when cases were declining across the northern hemisphere. How are these places doing now?

DC: up dramatically

https://covid-19.direct/metro/DC

Canada: all-time highs

https://www.worldometers.info/coronavirus/country/canada/

Germany: all-time highs

https://www.worldometers.info/coronavirus/country/germany/

US nationally: all-time highs

https://covid-19.direct/US

California: all-time highs

https://covid-19.direct/state/CA

New York: up dramatically

https://covid-19.direct/state/NY

Boston (where the "unified hospital system" was located): near all-time highs

https://covid-19.direct/metro/Boston

I could go on.

Anyone who attempted to conduct a similar analysis today would have to credibly conclude that masks have no protective effect whatsoever. But who knows...maybe they slightly alter the slope of the curve. It's impossible to tell without a controlled trial.

The german paper is particularly ironic, given that it was published approximately concurrently with a huge increase in diagnosed cases in the same city, which is now at all-time highs for the year:

https://www.pnas.org/content/early/2020/12/02/2015954117

https://gesundheit.jena.de/en/coronavirus

[ Parent | on HN ]

Re:London put in emergency lockdown as U.K. fights new strain by PaulDavisThe1st on Sunday December 20, 2020 @01:00AM (#25484220)

> Anyone who attempted to conduct a similar analysis today would have to credibly conclude that masks have no protective effect whatsoever.

Absolutely not the case. It would be just as credible, as has been noted by others in the comments here, to suggest that the major cause of spread is unmasked private gatherings.

> But who knows...maybe they slightly alter the slope of the curve. It's impossible to tell without a controlled trial.

I agree that without controlled trials, it is very difficult to tell definitively. That does not, however, translate into "there are lots of reasons to doubt ..."

[ Parent | on HN ]

Re:London put in emergency lockdown as U.K. fights new strain by rightbyte on Sunday December 20, 2020 @03:59PM (#25489443)

There was a empirical trail in Denmark. The difference between infection ratio and wearing a mask vs the control group was not significant.

https://www.acpjournals.org/doi/10.7326/M20-6817

Infection with SARS-CoV-2 occurred in 42 participants recommended masks (1.8%) and 53 control participants (2.1%). The between-group difference was −0.3 percentage point (95% CI, −1.2 to 0.4 percentage point; P = 0.38) (odds ratio, 0.82 [CI, 0.54 to 1.23]; P = 0.33). Multiple imputation accounting for loss to follow-up yielded similar results. Although the difference observed was not statistically significant, the 95% CIs are compatible with a 46% reduction to a 23% increase in infection.

[ Parent | on HN ]