How do you propose that working? Make it a legal requirement that everyone turn on GPS tracking on their phone and upload that to some central data base that then compares your movement with the movements of someone who's tested positive? That would be quite a feat of software engineering, and of course will have a lot of blackspots (eg: when you go inside a large building like a shopping mall or get an underground train), even without considering the data security issues and personal freedoms.
I'm pretty sure that data is already being tracked. There will be exceptions and imperfections as with any tracking system, but I'd favor a system that over-tests (e.g. SARS-CoV-2 tests for your neighbors on the other side of a wall) than one that under-tests (e.g. not bothering to trace contacts).
The problem is that track and trace only works if you have a relatively low number of cases. Otherwise the admin required to track down every contact rapidly implies an impractically huge organization size.
If you have thousands of new cases a day (and in the case of the UK have a 5 day lag before your test results come back) it becomes impractical to do track and trace.
The problem is that track and trace only works if you have a relatively low number of cases. Otherwise the admin required to track down every contact rapidly implies an impractically huge organization size.
If you have thousands of new cases a day (and in the case of the UK have a 5 day lag before your test results come back) it becomes impractical to do track and trace.
Dr Fauci made both points with commendable clarity in the USA and I am afraid they seem to be regarded by too many as inconvenient truths both sides of the pond.
We're at the aggressive tracking of new cases stage where I live. No new diagnoses in southern Saskatchewan, 4 in the north, 150 or so active cases in a pop of 1.1 million. We've had just less than 600 total cases. We're feeling quite blessed.
Certain businesses are allowed to open now. Lots of stipulations: health questions before entry to personal service businesses, e.g., haircuts, physical therapy.
-Workers must wear masks, gowns, eye protection. Sanitize everything between people.
-no inside waiting areas allowed. People must answer health questions before they leave home for appts, and again at time of entry and temp taken (which is not a good indicator of anything actually)
-Busses are running, rear door entry only, when they have enough passengers that they can't add another for 2m spacing they don't pick up anyone else.
-max group size is 10 people
-supposed to stay home unless you're specifically going somewhere.
-schools are not going to re-open until Sept, same as all post-secondary education. It is all online, which works as internet and cell phone data is free, and rural areas have been aggressively served by a public service orientation to internet and cellular.
-the request is that no-one come into the province. It's not enforced by law but there are road blocks and check points. You may not go north however: it is enforced by police and conservation officers.
The problem is that track and trace only works if you have a relatively low number of cases. Otherwise the admin required to track down every contact rapidly implies an impractically huge organization size.
If you have thousands of new cases a day (and in the case of the UK have a 5 day lag before your test results come back) it becomes impractical to do track and trace.
Dr Fauci made both points with commendable clarity in the USA and I am afraid they seem to be regarded by too many as inconvenient truths both sides of the pond.
I suspect that even identifying the bleeding obvious cases (that is, the ones which the patient comes up with off the tip of his/her tongue) and testing them would nevertheless make a sizable dent in the spread of the disease. It would certainly do better than giving up altogether (as we seem to be doing at present here) and letting Aunt Milly, who spent six hours sitting next to Patient X on the couch yesterday, vanish into the ether without so much as a warning. Or Dentist Y, who spent two hours this morning with her fingers in X's mouth. And if everybody sent for a test was required to cough up (ahem) these obvious names on a piece of paper, just in case-like, they wouldn't have faded from memory once the results came back--and the exercise would serve as an incidental reminder of how important social distancing is.
United Arab Emirates - 20,386 (13,657 / 6,523 / 206)
Bangladesh - 17,822 (14,192 / 3,361 / 269)
Poland - 17,204 (9,933 / 6,410 / 861)
Israel - 16,548 (4,052 / 12,232 / 264) 2.1%
Ukraine - 16,425 (12,270 / 3,716 / 439)
Japan - 16,049 (6,451 / 8,920 / 678)
Romania - 16,002 (7,005 / 7,961 / 1,036)
Austria - 15,997 (1,069 / 14,304 / 624) 4.2%
Indonesia - 15,438 (11,123 / 3,287 / 1,028)
Colombia - 12,930 (9,288 / 3,133 / 509)
South Africa - 12,074 (7,110 / 4,745 / 219)
Philippines - 11,618 (8,595 / 2,251 / 772)
Dominican Republic - 11,196 (7,566 / 3,221 / 409)
Kuwait - 11,028 (7,683 / 3,263 / 82)
South Korea - 10,991 (969 / 9,762 / 260) 2.6%
Denmark - 10,667 (1,471 / 8,663 / 533) 5.8%
Egypt - 10,431 (7,389 / 2,486 / 556)
Serbia - 10,295 (6,249 / 3,824 / 222)
The listings are in the format:
X. Country - [# of known cases] ([active] / [recovered] / [dead]) [%fatality rate]
Fatality rates are only listed for countries where the number of resolved cases (recovered + dead) exceeds the number of known active cases by a ratio of at least 2:1.
Italics indicate authoritarian countries whose official statistics are suspect. Other country's statistics are suspect if their testing regimes are substandard.
If American states were treated as individual countries twenty-eight of them would be on that list. New York would be ranked at #2, between "everywhere in the U.S. except New York" (#1) and Spain (#3). New Jersey would be between Turkey and Iran.
No countries have joined the 10,000 case club since the last compilation.
News item: the Wisconsin Supreme Court overturns the Safer at Home orders of Governor Evans on 13 May 2020. Unlike the US Supreme Court, those judges are partisan and are up for election every few years (staggered, of course). Last night, many bars in Wisconsin opened up and were packed.
This morning, 14 May 2020, my son who is a pastor in Kenosha Wisconsin issued this pastoral response to the decision: Facebook video.
One of my other sons, who owns a bar in Washington, is looking at what he will do as Washington state begins to open. For the time being, he will continue to do only take out until we reach stage four in the re-opening. He probably could do it in stage 2 provided he limits capacity to 50% and keeps a list of all his patrons each day (for contact tracing if necessary), but he wants to keep everyone safe.
As part of its response, Moscow’s health department revealed that more than 60% of deaths of coronavirus patients in the capital were not tallied in the city’s official death count from the disease because an autopsy showed they had died of other causes.
Well, there's a thing. I foresee a modification to the Trump playbook as guidance to those States supporting him and relaxing social distancing. "Just say the deaths are caused by something else, and then the spike disappears!" Simples!
That has been an ongoing argument by skeptics, that many deaths are not recorded as covid, but end up in the covid total. So they can say, look, covid is no worse than flu. I don't know where they get information about death certificates.
Well, there's a thing. I foresee a modification to the Trump playbook as guidance to those States supporting him and relaxing social distancing. "Just say the deaths are caused by something else, and then the spike disappears!" Simples!
The White House has pressed the CDC, in particular, to work with states to change how they count coronavirus deaths and report them back to the federal government, according to two officials with knowledge of those conversations. And Deborah Birx, the coordinator of the administration’s coronavirus task force, has urged CDC officials to exclude from coronavirus death-count reporting some of those individuals who either do not have confirmed lab results and are presumed positive or who have the virus and may not have died as a direct result of it, according to three senior administration officials.
As part of its response, Moscow’s health department revealed that more than 60% of deaths of coronavirus patients in the capital were not tallied in the city’s official death count from the disease because an autopsy showed they had died of other causes.
Well, there's a thing. I foresee a modification to the Trump playbook as guidance to those States supporting him and relaxing social distancing. "Just say the deaths are caused by something else, and then the spike disappears!" Simples!
I have no detailed knowledge of Russian healthcare / pathology services. However, in normal circumstances only a very small minority of people ever have an autopsy in most countries. They are expensive (and in the case of infectious diseases, risky to those performing them) and rarely needed. In most cases we know (with sufficient confidence) the cause of death.
Thus the notion that over 60% of people who died having tested positive for SARS-CoV2 went on to have an autopsy is prima facie* nonsense.
That has been an ongoing argument by skeptics, that many deaths are not recorded as covid, but end up in the covid total. So they can say, look, covid is no worse than flu. I don't know where they get information about death certificates.
It's made up. Look at total deaths, and you see that deaths tagged COVID-19 undercount the current peak in the death rate. For my state, by perhaps 25%. Excess deaths in the current COVID-19 timeframe are worse than excess deaths in the Jan 2018 'flu by a factor of 3 or so (and that's with all the lockdowns limiting the spread of the virus).
Unsurprising, but it doesn't actually matter*. As several of us have been saying for a long time, the numbers that actually matter are the excess death figures. The headline COVID death numbers will let Trump lie to us for a handful of weeks, but then the math will catch up with him.
*to people with a brain. I realize this excludes the likes of the people currently protesting against lockdowns, but they're a lost cause anyway - they've conditioned themselves not to believe science.
Unsurprising, but it doesn't actually matter*. As several of us have been saying for a long time, the numbers that actually matter are the excess death figures. The headline COVID death numbers will let Trump lie to us for a handful of weeks, but then the math will catch up with him.
*to people with a brain. I realize this excludes the likes of the people currently protesting against lockdowns, but they're a lost cause anyway - they've conditioned themselves not to believe science.
I wish it didn't matter! The narrative battle re facts and "alternative facts" is real, however much I wish it wasn't. And data re new cases is also significant; that obviously cannot be obtained except by direct measurement.
Essentially, based on a sample of 11,000 people the point estimate is that 0.27% of the community population have SARS-Cov2 (95% confidence interval: 0.17% to 0.41%).
Knowing that the ONS did this work, I suspect it was rigorous methodology but there will still be big regional variations and other potential issues with these data.
So we should be cautious about this number but it's a really big step forward. They have separate estimates for healthcare workers and care home residents, as well as an age breakdown. The data is for the 2 weeks up to 10th May.
But, if we assume it's close to accurate, it tells us that we are not in a position to do track and trace effectively. These data are a prevalence rather than an incidence. What that means is number of people who are infected at any given point in time; it doesn't tell you how many new infections you are getting per day. However, we also know that people with Covid-19 do not test positive (by nasal swab) for the whole time they have the infection - possibly only for the first 48hrs. (This is another of the things that is unknown).
Anyway - it enables us to do a first guesstimate of how many tests we need to be able to do for a test and trace program. A prevalence of 0.17 to 0.41% corresponds to something like 100,000 to 250,000 people. So if we started from now and said we have something like 200,000 people who test positive. We then have to have in-depth interviews with all of them to find out who their relevant contacts are. Then we have to trace all these people and test them and promptly (probably at least 10x as many people). That's just totally impractical with these kind of numbers. In reality, it's even more complex than this because a big chunk of these people who are positive are also asymptomatic so we don't know about them unless we are testing everybody...
Conversely, if only 0.27% of the community has the virus then, with a total lock-down, we will see numbers continue to fall...
Look out in the next day or so for some reports on how these data inform the plan going forward. Clever viral epidemiologists will be modelling this and will have a definitive answer but my very quick (and crude back-of-an-envelope-type) squiz at this suggests the numbers are far too high for track and trace to be practical.
Clever viral epidemiologists will be modelling this and will have a definitive answer but my very quick (and crude back-of-an-envelope-type) squiz at this suggests the numbers are far too high for track and trace to be practical.
Thanks for the ONS link.
My sense is that full-on contact tracing is a non-starter, but that sensible distancing measures (maintaining distance, masks, not sharing airspace with a bunch of random strangers) might mean that just testing people that work in close proximity to a positive tester might do a lot of the work.
Except that I don't think you can do sensible distancing measures in a city that relies on public transport. I'd love to be convinced that spending half an hour in the tube opposite a masked virus-shedder was safe, but that's not where I'd put my money. Do you have an opinion?
On the public transit issue, we were told by our employer today that we will be continuing to work substantially from home until this is over. I'm sure public transit exposure is a big part of that equation, especially for a city like Toronto.
Clever viral epidemiologists will be modelling this and will have a definitive answer but my very quick (and crude back-of-an-envelope-type) squiz at this suggests the numbers are far too high for track and trace to be practical.
Thanks for the ONS link.
My sense is that full-on contact tracing is a non-starter, but that sensible distancing measures (maintaining distance, masks, not sharing airspace with a bunch of random strangers) might mean that just testing people that work in close proximity to a positive tester might do a lot of the work.
Except that I don't think you can do sensible distancing measures in a city that relies on public transport. I'd love to be convinced that spending half an hour in the tube opposite a masked virus-shedder was safe, but that's not where I'd put my money. Do you have an opinion?
The data on standard masks are coming out slowly with quite differing opinions (which mostly reflects that this is all new and so we don't know yet) but; no, I'd be very surprised if a mask provided sufficient protection. There's no data to suggest they would be adequate and do anything more than augment social distancing's effectiveness.
I think any tracking and tracing based on local clusters will help. It will clearly be more effective if the new case numbers become more manageable. Currently for the UK (and recognising that more testing may well push the numbers up) the confirmed positive numbers are still over 3,000 a day. Not sure of the clustering or spreading these numbers represent.
In the USA, that new case load seems to have plateaued at about 20,000 a day, which as a proportion of the population is not all that dissimilar to UK levels.
So far as tracking and tracing are concerned in both countries, the degree of effectiveness will probably depend on where the clusters are. On general grounds, tracking and tracing look like a very tall order.
United Arab Emirates - 21,084 (13,946 / 6,930 / 208)
Bangladesh - 18,863 (15,219 / 3,361 / 283)
Poland - 17,615 (10,036 / 6,696 / 883)
Ukraine - 16,847 (12,248 / 4,143 / 456) 9.9%
Israel - 16,579 (3,793 / 12,521 / 265)
Romania - 16,247 (6,141 / 9,053 / 1,053)
Japan - 16,120 (5,555 / 9,868 / 697)
Austria - 16,058 (1,027 / 14,405 / 626) 4.2%
Indonesia - 16,006 (11,445 / 3,518 / 1,043)
Colombia - 13,610 (9,727 / 3,358 / 525)
South Africa - 12,739 (6,825 / 5,676 / 238)
Kuwait - 11,975 (8,436 / 3,451 / 88)
Philippines - 11,876 (8,749 / 2,337 / 790)
Dominican Republic - 11,320 (7,547 / 3,351 / 422)
South Korea - 11,018 (937 / 9,821 / 260) 2.6%
Egypt - 10,829 (7,632 / 2,626 / 571)
Denmark - 10,713 (1,371 / 8,805 / 537) 5.7%
Serbia - 10,374 (6,066 / 4,084 / 224)
The listings are in the format:
X. Country - [# of known cases] ([active] / [recovered] / [dead]) [%fatality rate]
Fatality rates are only listed for countries where the number of resolved cases (recovered + dead) exceeds the number of known active cases by a ratio of at least 2:1.
Italics indicate authoritarian countries whose official statistics are suspect. Other country's statistics are suspect if their testing regimes are substandard.
If American states were treated as individual countries twenty-eight of them would be on that list. New York would be ranked at #2, between "everywhere in the U.S. except New York" (#1) and Spain (#3). New Jersey would be between Turkey and Iran.
No countries have joined the 10,000 case club since the last compilation.
Reminds me of a story told by Solzhenitsyn in one of the Gulag books. A nail manufacturer was unable to meet its production targets because of a machinery breakdown and months of delay in getting spare parts. The penalty for failure was Siberia. So they devised a way round it based on the fact that their target was measured in kilogram weight rather than numbers of nails. They made a large mold by hand, melted the metal, cast one giant nail, and added it to stock.
Many reports that cases in London have dropped to 24 a day. Hopefully, people don't become demob happy, and want pubs open, etc. These figures should be treated with caution, but I suppose they offer some hope.
The gulag story reminded me of something. This week’s “More or Less” on Radio 4 investigated how the UK met its testing targets. Apparently this was “achieved” by including putting testing kits in the post just before the deadline, so there’s no evidence that the number of tests quoted would ever have been carried out, and it would have been impossible for them to have been completed by the date claimed.
The UK government has been "imaginative" in quite a lot of statements about what they've achieved. Including 40,000 kits put in the post just before announcing the 100,000 tests per day has been met hasn't been the worst of them (because, at least those tests were there ... although there were subsequent reports that some of the posted kits were incomplete and thus unusable).
Reporting number of PPE items supplied was also quite imaginative ... there would be very few people outwith government who would consider counting a pair of gloves as two items - when we order PPE at work we consider a box of gloves to be a single item (when we shut up a couple of months back we gathered up all our unopen boxes of PPE, mostly gloves, and took them to a local hospital where they could be of use rather than sitting in cupboards of closed buildings). And, there was the number of gowns supplied also including an order just placed with a Turkish supplier, which after delays and the cost of dispatching an RAF aircraft to uplift them turned out to be a lower grade of protection than needed for frontline hospital use.
NZ has moved down to Alert Level 2 in a 4 point scale (which we copied from somewhere in Asia). I caught a bus into town today. Only half the seats are being used and no standing is allowed. Only a limited number of people are allowed in the library too. Names and contact details are written on a list for contact tracing if needed. When the number is reached it's one out, one in.. Borrowers are asked to limit their time in the library to 2 hours.
It was weird. The library is usually a very vibrant place. I can spend hours browsing and looking at new books, checking out information with staff, meeting friends. Today I was there for about half an hour and just wanted to go home.
Today was the first day it was open , so I'm hoping as we get used to it will feel better.
Shops, cafes and restaurants are open, but not pubs* because people tend not to be as careful about physical distance when alcohol is involved. Schools, Universities and child care centres are open on Monday.
My oldest brother has Parkinson's and lives in the hospital section of a care home. He is allowed one half hour visit once a week from a family member. I had booked tickets to see him before we went into lockdown, but instead I will post him weekly cards and post cards. I would like to see him, but over half the 21 deaths here have happened in care homes, and the thought of being responsible for a cluster is horrifying.
*I think the policy on pubs will be reviewed in a fortnight.
OK. How utilitarian are we being and how utilitarian can we get? Kids have to go back to school, youngest on up. Anybody healthy under 40 can go back to work for a start. Maximize herd immunity and protect the vulnerable. The balance is measured by those on ventilators. There is no other quantifiable or justifiable measure?
As doctors learn more, they are growing increasingly convinced that the syndrome currently sickening children is not actually Kawasaki disease, but rather a separate inflammatory condition that produces similar symptoms. A pediatric critical care physician told the New York Times on May 11 that the inflammatory syndrome linked to COVID-19 seems to affect the heart differently than Kawasaki disease, and results in toxic shock more frequently.
Medical opinion isn't settled on this. I think there is always concern that some folks who get these viruses may be subject to a cytokine storm or some similar reaction, during which a healthy immune system may become a liability. I don't know enough about these cases, but would not be surprised if there were such concerns.
Martin54
It strikes me that it might be a good idea to hang back re the risk to under 40s and children. So far, the demographic evidence points that way, but this is a new virus and we're still finding out stuff about it.
Kids have to go back to school, youngest on up. Anybody healthy under 40 can go back to work for a start.
That is contradictory. If kids go back to school they will need teachers. But, a large proportion of teachers are older than 40. So, if only under 40s go back to work most schools won't have enough teachers to allow kids to come back.
Maximize herd immunity and protect the vulnerable.
You know, I've read this phrase -- "herd immunity" -- some 2-3 times (at least) in the course of this thread. I'm a non-medical person, so forgive this potentially ignorant question, but: what herd immunity?
It's my understanding, which I'm happy to have corrected if mistaken, that herd immunity can be achieved in one of two basic ways: either (1) naturally-occurring immunity (enough members of an affected population survives to keep the species in business); or (2) the development of effective preventive/curative measures inhibits spread of the pathogen.
Am I correct in my belief that neither of these situations exists with respect to the malady/maladies under discussion, and that talk of "herd immunity" is at best premature?
While I grant that's at least one theoretical possibility, another theoretical possibility is re-infection among survivors with resulting increased morbidity. It's my (again, possibly incorrect) understanding that we don't yet know whether surviving a bout of COVID-19 confers any immunity, or to what extent, or for how long, or to what aspects of survivors' health.
If COVID is like measles -- you get it, recover, and are now immune -- that's fine for those who survive. Alternatively, you get a shot and never contract measles at all. Or you don't get a shot for sound medical reasons, but are protected by being surrounded by folks who did get shots or survived measles and can't pass it on to you, all well and good.
But if COVID is like the flu, which alters its lines of attack from one season to the next, that's another story and requires ongoing attention to some 7 billion human inhabits.
And if it turns out that we can't figure COVID out, well, let's not go there
With the massive numbers we've created, there will no doubt be survivors. May they be wiser than we have been.
And if it turns out that we can't figure COVID out, well, let's not go there With the massive numbers we've created, there will no doubt be survivors. May they be wiser than we have been.
If we never find a way to confer lasting immunity then we’ll either have to destroy our whole society and culture or accept a whole lot of death. Neither is a good choice, but I’d choose to preserve our society and culture even at the cost of many lives.
Hell, about half the population of Europe died in the Black Death, but European cultures still thrived afterwards. And for the survivors it was even better in many ways than it had been before.
The idea is that we (the survivors, anyway) acquire herd immunity through simply allowing everybody to get the virus.
No. We gain herd immunity by developing a vaccine. Until then we socially distance so that this thing doesn't become the same horror story as the 1918 flu.
Way up thread I posted a video on herd immunity. If the Ro of Covid is 2.3, that means one person will infect around three people. That would mean that if 60% of the herd is immune, the virus would likely be in check. Herd immunity happens if 60% of the herd had sufficient antibodies against the virus. This can come in two ways: if enough people have been exposed naturally-this is what happened with the pandemic of 1918/19--or if people get vaccinated.
The great unknown about this disease is how many people get the disease and are asymptomatic or have such a mild case they think it is no more than a cold. Some projections say up to 80% of COVID cases are asymptomatic. But we really will not know until we have a test that can reliably show antibodies.
United Arab Emirates - 21,831 (14,293 / 7,328 / 210)
Bangladesh - 20,065 (15,885 / 3,882 / 298)
Poland - 18,016 (10,191 / 6,918 / 907)
Ukraine - 17,330 (12,381 / 4,473 / 476)
Israel - 16,589 (3,736 / 12,587 / 266) 2.1%
Indonesia - 16,496 (11,617 / 3,803 / 1,076)
Romania - 16,437 (5,997 / 9,370 / 1,070)
Japan - 16,203 (5,152 / 10,338 / 713) 6.5%
Austria - 16,109 (1,010 / 14,471 / 628) 4.2%
Colombia - 14,216 (10,210 / 3,460 / 546)
South Africa - 13,524 (7,194 / 6,083 / 247)
Kuwait - 12,860 (9,124 / 3,640 / 96)
Philippines - 12,091 (8,825 / 2,460 / 806)
Dominican Republic - 11,739 (7,758 / 3,557 / 424)
Egypt - 11,228 (7,837 / 2,799 / 592)
South Korea - 11,037 (924 / 9,851 / 262) 2.6%
Denmark - 10,791 (1,295 / 8,959 / 537) 5.7%
Serbia - 10,438 (5,912 / 4,301 / 225)
The listings are in the format:
X. Country - [# of known cases] ([active] / [recovered] / [dead]) [%fatality rate]
Fatality rates are only listed for countries where the number of resolved cases (recovered + dead) exceeds the number of known active cases by a ratio of at least 2:1.
Italics indicate authoritarian countries whose official statistics are suspect. Other country's statistics are suspect if their testing regimes are substandard.
If American states were treated as individual countries twenty-eight of them would be on that list. New York would be ranked at #2, between "everywhere in the U.S. except New York" (#1) and Spain (#3). New Jersey would be between Turkey and Iran.
No countries have joined the 10,000 case club since the last compilation.
Maximize herd immunity and protect the vulnerable.
You know, I've read this phrase -- "herd immunity" -- some 2-3 times (at least) in the course of this thread. I'm a non-medical person, so forgive this potentially ignorant question, but: what herd immunity?
It's my understanding, which I'm happy to have corrected if mistaken, that herd immunity can be achieved in one of two basic ways: either (1) naturally-occurring immunity (enough members of an affected population survives to keep the species in business); or (2) the development of effective preventive/curative measures inhibits spread of the pathogen.
Am I correct in my belief that neither of these situations exists with respect to the malady/maladies under discussion, and that talk of "herd immunity" is at best premature?
I am not a doctor nor an epidemiologist, but since we're all becoming amateur epidemiologists these days I'll take a whack at this.
The concept of "herd immunity" is based on the reproduction rate of the disease (usually abbreviated as R). This number represents the number of people an infected person will infect. In short:
R > 0 --> exponential growth of cases as each "generation" of the disease is more numerous
R = 0 --> cases "plateau", staying more or less constant
R < 0 --> disease shrinks exponentially as each "generation" of the disease is less numerous, eventually disappearing
R isn't a natural constant and can be altered by human factors (e.g. hand washing, social distancing, etc.) The base reproduction rate (R0) is how fast a disease will spread in a population with no immunity, essentially the environment that SARS-CoV-2 found itself in when it first encountered humans. The biggest factor affecting R is the number of immune members of the population who cannot pass along the disease. At some point the number of people with immunity becomes great enough that the disease can no longer propagate effectively, driving R below 1.
So what proportion of a population has to be immune before "herd immunity" is achieved? Well, that depends on how contagious the disease is. For something like diptheria (not very contagious) you can achieve herd immunity with something like 60%-70% of the population being immune. For something like measles (very contagious) you need numbers more like 90%-95% of the population with immunity. SARS-CoV-2 seems to be towards the "measles" end of the contagiousness spectrum. In other words, for those advocating achieving "herd immunity" by just letting the disease run unchecked the plan is to expose pretty much everyone to the disease, resulting in millions of deaths. (Best guess for COVID-19 mortality rates is about 1%, but that's just a guess. The mortality rates we're seeing in official figures range from 2% to 13%, but insufficient testing may be a distorting factor.)
Of course there are other factors to consider. As @Ohherpoints out we don't really know how durable immunity to COVID-19 is for those who recover. There's also the fact that even if individuals have durable immunity, societies do not since immunity is not passed along via reproduction.
There's also the common pretense that a certain small percentage of people will die and everyone else will recover and be just like new. There's a lot we don't know about this virus, but it seems like a fairly large percentage of those who recover from COVID-19 (a larger percentage than those who die) will suffer long-term damage. Heart and lungs definitely. Possibly kidneys and liver as well. As I said, there's a lot we're still uncertain about. Any plan which advocates mass death (as any plan premised on "herd immunity" absent a vaccine does) must also plan for an even larger number of people with permanent diminished physical capacities.
Hell, about half the population of Europe died in the Black Death, but European cultures still thrived afterwards. And for the survivors it was even better in many ways than it had been before.
Did European culture "thrive" in the wake of the Black Death? I'd argue that the warping effect of the plague boosted European obsessions with witchcraft and anti-Semitism as scapegoats for the mass death. Whether "culture" was "better in many ways than it had been before" depended in large part upon whether you were a woman or a Jew. I guess if you're comfortable with plans involving mass death you're probably pretty comfortable with witch-burnings and pogroms as well.
Comments
The problem is that track and trace only works if you have a relatively low number of cases. Otherwise the admin required to track down every contact rapidly implies an impractically huge organization size.
If you have thousands of new cases a day (and in the case of the UK have a 5 day lag before your test results come back) it becomes impractical to do track and trace.
Dr Fauci made both points with commendable clarity in the USA and I am afraid they seem to be regarded by too many as inconvenient truths both sides of the pond.
Certain businesses are allowed to open now. Lots of stipulations: health questions before entry to personal service businesses, e.g., haircuts, physical therapy.
-Workers must wear masks, gowns, eye protection. Sanitize everything between people.
-no inside waiting areas allowed. People must answer health questions before they leave home for appts, and again at time of entry and temp taken (which is not a good indicator of anything actually)
-Busses are running, rear door entry only, when they have enough passengers that they can't add another for 2m spacing they don't pick up anyone else.
-max group size is 10 people
-supposed to stay home unless you're specifically going somewhere.
-schools are not going to re-open until Sept, same as all post-secondary education. It is all online, which works as internet and cell phone data is free, and rural areas have been aggressively served by a public service orientation to internet and cellular.
-the request is that no-one come into the province. It's not enforced by law but there are road blocks and check points. You may not go north however: it is enforced by police and conservation officers.
I suspect that even identifying the bleeding obvious cases (that is, the ones which the patient comes up with off the tip of his/her tongue) and testing them would nevertheless make a sizable dent in the spread of the disease. It would certainly do better than giving up altogether (as we seem to be doing at present here) and letting Aunt Milly, who spent six hours sitting next to Patient X on the couch yesterday, vanish into the ether without so much as a warning. Or Dentist Y, who spent two hours this morning with her fingers in X's mouth. And if everybody sent for a test was required to cough up (ahem) these obvious names on a piece of paper, just in case-like, they wouldn't have faded from memory once the results came back--and the exercise would serve as an incidental reminder of how important social distancing is.
The listings are in the format:
X. Country - [# of known cases] ([active] / [recovered] / [dead]) [%fatality rate]
Fatality rates are only listed for countries where the number of resolved cases (recovered + dead) exceeds the number of known active cases by a ratio of at least 2:1.
Italics indicate authoritarian countries whose official statistics are suspect. Other country's statistics are suspect if their testing regimes are substandard.
If American states were treated as individual countries twenty-eight of them would be on that list. New York would be ranked at #2, between "everywhere in the U.S. except New York" (#1) and Spain (#3). New Jersey would be between Turkey and Iran.
No countries have joined the 10,000 case club since the last compilation.
Actual deaths exceed 100,000.
This morning, 14 May 2020, my son who is a pastor in Kenosha Wisconsin issued this pastoral response to the decision: Facebook video.
One of my other sons, who owns a bar in Washington, is looking at what he will do as Washington state begins to open. For the time being, he will continue to do only take out until we reach stage four in the re-opening. He probably could do it in stage 2 provided he limits capacity to 50% and keeps a list of all his patrons each day (for contact tracing if necessary), but he wants to keep everyone safe.
Now here is a nice quote
Well, there's a thing. I foresee a modification to the Trump playbook as guidance to those States supporting him and relaxing social distancing. "Just say the deaths are caused by something else, and then the spike disappears!" Simples!
Foresee?
And so the prophecy came to pass.
I have no detailed knowledge of Russian healthcare / pathology services. However, in normal circumstances only a very small minority of people ever have an autopsy in most countries. They are expensive (and in the case of infectious diseases, risky to those performing them) and rarely needed. In most cases we know (with sufficient confidence) the cause of death.
Thus the notion that over 60% of people who died having tested positive for SARS-CoV2 went on to have an autopsy is prima facie* nonsense.
AFZ
*Latin but accepted in English
It's made up. Look at total deaths, and you see that deaths tagged COVID-19 undercount the current peak in the death rate. For my state, by perhaps 25%. Excess deaths in the current COVID-19 timeframe are worse than excess deaths in the Jan 2018 'flu by a factor of 3 or so (and that's with all the lockdowns limiting the spread of the virus).
Here's the data.
Unsurprising, but it doesn't actually matter*. As several of us have been saying for a long time, the numbers that actually matter are the excess death figures. The headline COVID death numbers will let Trump lie to us for a handful of weeks, but then the math will catch up with him.
*to people with a brain. I realize this excludes the likes of the people currently protesting against lockdowns, but they're a lost cause anyway - they've conditioned themselves not to believe science.
I wish it didn't matter! The narrative battle re facts and "alternative facts" is real, however much I wish it wasn't. And data re new cases is also significant; that obviously cannot be obtained except by direct measurement.
Essentially, based on a sample of 11,000 people the point estimate is that 0.27% of the community population have SARS-Cov2 (95% confidence interval: 0.17% to 0.41%).
Knowing that the ONS did this work, I suspect it was rigorous methodology but there will still be big regional variations and other potential issues with these data.
So we should be cautious about this number but it's a really big step forward. They have separate estimates for healthcare workers and care home residents, as well as an age breakdown. The data is for the 2 weeks up to 10th May.
But, if we assume it's close to accurate, it tells us that we are not in a position to do track and trace effectively. These data are a prevalence rather than an incidence. What that means is number of people who are infected at any given point in time; it doesn't tell you how many new infections you are getting per day. However, we also know that people with Covid-19 do not test positive (by nasal swab) for the whole time they have the infection - possibly only for the first 48hrs. (This is another of the things that is unknown).
Anyway - it enables us to do a first guesstimate of how many tests we need to be able to do for a test and trace program. A prevalence of 0.17 to 0.41% corresponds to something like 100,000 to 250,000 people. So if we started from now and said we have something like 200,000 people who test positive. We then have to have in-depth interviews with all of them to find out who their relevant contacts are. Then we have to trace all these people and test them and promptly (probably at least 10x as many people). That's just totally impractical with these kind of numbers. In reality, it's even more complex than this because a big chunk of these people who are positive are also asymptomatic so we don't know about them unless we are testing everybody...
Conversely, if only 0.27% of the community has the virus then, with a total lock-down, we will see numbers continue to fall...
Look out in the next day or so for some reports on how these data inform the plan going forward. Clever viral epidemiologists will be modelling this and will have a definitive answer but my very quick (and crude back-of-an-envelope-type) squiz at this suggests the numbers are far too high for track and trace to be practical.
AFZ
Thanks for the ONS link.
My sense is that full-on contact tracing is a non-starter, but that sensible distancing measures (maintaining distance, masks, not sharing airspace with a bunch of random strangers) might mean that just testing people that work in close proximity to a positive tester might do a lot of the work.
Except that I don't think you can do sensible distancing measures in a city that relies on public transport. I'd love to be convinced that spending half an hour in the tube opposite a masked virus-shedder was safe, but that's not where I'd put my money. Do you have an opinion?
The data on standard masks are coming out slowly with quite differing opinions (which mostly reflects that this is all new and so we don't know yet) but; no, I'd be very surprised if a mask provided sufficient protection. There's no data to suggest they would be adequate and do anything more than augment social distancing's effectiveness.
AFZ
In the USA, that new case load seems to have plateaued at about 20,000 a day, which as a proportion of the population is not all that dissimilar to UK levels.
So far as tracking and tracing are concerned in both countries, the degree of effectiveness will probably depend on where the clusters are. On general grounds, tracking and tracing look like a very tall order.
The listings are in the format:
X. Country - [# of known cases] ([active] / [recovered] / [dead]) [%fatality rate]
Fatality rates are only listed for countries where the number of resolved cases (recovered + dead) exceeds the number of known active cases by a ratio of at least 2:1.
Italics indicate authoritarian countries whose official statistics are suspect. Other country's statistics are suspect if their testing regimes are substandard.
If American states were treated as individual countries twenty-eight of them would be on that list. New York would be ranked at #2, between "everywhere in the U.S. except New York" (#1) and Spain (#3). New Jersey would be between Turkey and Iran.
No countries have joined the 10,000 case club since the last compilation.
It looks as though the excess deaths measuring rod will reveal the extent of the manipulation, and more clearly by the end of the month.
But only looks like. If Putin wants to keep the lid on, the statistics of total deaths will also end up being manipulated.
See what happens if you whistleblow in Russia.
Reminds me of a story told by Solzhenitsyn in one of the Gulag books. A nail manufacturer was unable to meet its production targets because of a machinery breakdown and months of delay in getting spare parts. The penalty for failure was Siberia. So they devised a way round it based on the fact that their target was measured in kilogram weight rather than numbers of nails. They made a large mold by hand, melted the metal, cast one giant nail, and added it to stock.
Lies and threats breed more lies.
Reporting number of PPE items supplied was also quite imaginative ... there would be very few people outwith government who would consider counting a pair of gloves as two items - when we order PPE at work we consider a box of gloves to be a single item (when we shut up a couple of months back we gathered up all our unopen boxes of PPE, mostly gloves, and took them to a local hospital where they could be of use rather than sitting in cupboards of closed buildings). And, there was the number of gowns supplied also including an order just placed with a Turkish supplier, which after delays and the cost of dispatching an RAF aircraft to uplift them turned out to be a lower grade of protection than needed for frontline hospital use.
What more could we expect from Johnson and his crew?
It was weird. The library is usually a very vibrant place. I can spend hours browsing and looking at new books, checking out information with staff, meeting friends. Today I was there for about half an hour and just wanted to go home.
Today was the first day it was open , so I'm hoping as we get used to it will feel better.
Shops, cafes and restaurants are open, but not pubs* because people tend not to be as careful about physical distance when alcohol is involved. Schools, Universities and child care centres are open on Monday.
My oldest brother has Parkinson's and lives in the hospital section of a care home. He is allowed one half hour visit once a week from a family member. I had booked tickets to see him before we went into lockdown, but instead I will post him weekly cards and post cards. I would like to see him, but over half the 21 deaths here have happened in care homes, and the thought of being responsible for a cluster is horrifying.
*I think the policy on pubs will be reviewed in a fortnight.
Indeed you have, along with many others...
@Huia - I don't doubt for a moment that coming out of lockdown is going to feel weird, at least for a time.
I hope your brother enjoys his weekly mailing - a good idea, and, as you say, a lot safer, however much you might want to visit him in 'reality'.
Or that he might get it, despite what a future test says?
This link suggests otherwise.
In particular this quote.
Medical opinion isn't settled on this. I think there is always concern that some folks who get these viruses may be subject to a cytokine storm or some similar reaction, during which a healthy immune system may become a liability. I don't know enough about these cases, but would not be surprised if there were such concerns.
Martin54
It strikes me that it might be a good idea to hang back re the risk to under 40s and children. So far, the demographic evidence points that way, but this is a new virus and we're still finding out stuff about it.
You know, I've read this phrase -- "herd immunity" -- some 2-3 times (at least) in the course of this thread. I'm a non-medical person, so forgive this potentially ignorant question, but: what herd immunity?
It's my understanding, which I'm happy to have corrected if mistaken, that herd immunity can be achieved in one of two basic ways: either (1) naturally-occurring immunity (enough members of an affected population survives to keep the species in business); or (2) the development of effective preventive/curative measures inhibits spread of the pathogen.
Am I correct in my belief that neither of these situations exists with respect to the malady/maladies under discussion, and that talk of "herd immunity" is at best premature?
The idea is that we (the survivors, anyway) acquire herd immunity through simply allowing everybody to get the virus.
If COVID is like measles -- you get it, recover, and are now immune -- that's fine for those who survive. Alternatively, you get a shot and never contract measles at all. Or you don't get a shot for sound medical reasons, but are protected by being surrounded by folks who did get shots or survived measles and can't pass it on to you, all well and good.
But if COVID is like the flu, which alters its lines of attack from one season to the next, that's another story and requires ongoing attention to some 7 billion human inhabits.
And if it turns out that we can't figure COVID out, well, let's not go there
With the massive numbers we've created, there will no doubt be survivors. May they be wiser than we have been.
If we never find a way to confer lasting immunity then we’ll either have to destroy our whole society and culture or accept a whole lot of death. Neither is a good choice, but I’d choose to preserve our society and culture even at the cost of many lives.
Hell, about half the population of Europe died in the Black Death, but European cultures still thrived afterwards. And for the survivors it was even better in many ways than it had been before.
The great unknown about this disease is how many people get the disease and are asymptomatic or have such a mild case they think it is no more than a cold. Some projections say up to 80% of COVID cases are asymptomatic. But we really will not know until we have a test that can reliably show antibodies.
The listings are in the format:
X. Country - [# of known cases] ([active] / [recovered] / [dead]) [%fatality rate]
Fatality rates are only listed for countries where the number of resolved cases (recovered + dead) exceeds the number of known active cases by a ratio of at least 2:1.
Italics indicate authoritarian countries whose official statistics are suspect. Other country's statistics are suspect if their testing regimes are substandard.
If American states were treated as individual countries twenty-eight of them would be on that list. New York would be ranked at #2, between "everywhere in the U.S. except New York" (#1) and Spain (#3). New Jersey would be between Turkey and Iran.
No countries have joined the 10,000 case club since the last compilation.
I am not a doctor nor an epidemiologist, but since we're all becoming amateur epidemiologists these days I'll take a whack at this.
The concept of "herd immunity" is based on the reproduction rate of the disease (usually abbreviated as R). This number represents the number of people an infected person will infect. In short:
R isn't a natural constant and can be altered by human factors (e.g. hand washing, social distancing, etc.) The base reproduction rate (R0) is how fast a disease will spread in a population with no immunity, essentially the environment that SARS-CoV-2 found itself in when it first encountered humans. The biggest factor affecting R is the number of immune members of the population who cannot pass along the disease. At some point the number of people with immunity becomes great enough that the disease can no longer propagate effectively, driving R below 1.
So what proportion of a population has to be immune before "herd immunity" is achieved? Well, that depends on how contagious the disease is. For something like diptheria (not very contagious) you can achieve herd immunity with something like 60%-70% of the population being immune. For something like measles (very contagious) you need numbers more like 90%-95% of the population with immunity. SARS-CoV-2 seems to be towards the "measles" end of the contagiousness spectrum. In other words, for those advocating achieving "herd immunity" by just letting the disease run unchecked the plan is to expose pretty much everyone to the disease, resulting in millions of deaths. (Best guess for COVID-19 mortality rates is about 1%, but that's just a guess. The mortality rates we're seeing in official figures range from 2% to 13%, but insufficient testing may be a distorting factor.)
Of course there are other factors to consider. As @Ohher points out we don't really know how durable immunity to COVID-19 is for those who recover. There's also the fact that even if individuals have durable immunity, societies do not since immunity is not passed along via reproduction.
There's also the common pretense that a certain small percentage of people will die and everyone else will recover and be just like new. There's a lot we don't know about this virus, but it seems like a fairly large percentage of those who recover from COVID-19 (a larger percentage than those who die) will suffer long-term damage. Heart and lungs definitely. Possibly kidneys and liver as well. As I said, there's a lot we're still uncertain about. Any plan which advocates mass death (as any plan premised on "herd immunity" absent a vaccine does) must also plan for an even larger number of people with permanent diminished physical capacities.
Did European culture "thrive" in the wake of the Black Death? I'd argue that the warping effect of the plague boosted European obsessions with witchcraft and anti-Semitism as scapegoats for the mass death. Whether "culture" was "better in many ways than it had been before" depended in large part upon whether you were a woman or a Jew. I guess if you're comfortable with plans involving mass death you're probably pretty comfortable with witch-burnings and pogroms as well.