You may find this interesting. Stanford University had done a sample test study to find out how many people had been infected/exposed to Covid19 virus by doing blood test in a sample of 3,330 people out of 2 mil total population.
Results
The unadjusted prevalence of antibodies to SARS-CoV-2 in Santa Clara County was 1.5% (exact binomial 95CI 1.11-1.97%), and the population-weighted prevalence was 2.81% (95CI 2.24-3.37%).
Under the three scenarios for test performance characteristics, the population prevalence of COVID-19 in Santa Clara ranged from 2.49% (95CI 1.80-3.17%) to 4.16% (2.58-5.70%).
These prevalence estimates represent a range between 48,000 and 81,000 people infected in Santa Clara County by early April, 50-85-fold more than the number of confirmed cases.
Conclusions
The population prevalence of SARS-CoV-2 antibodies in Santa Clara County implies that the infection is much more widespread than indicated by the number of confirmed cases.
Population prevalence estimates can now be used to calibrate epidemic and mortality projections.
I must ask how much testing was done in Santa Clara to determine there were less than 1000 cases to begin with? Was it a matter of them suspecting the actual number of people in that area was higher, but testing was not available/done more extensively to get a more accurate number of total cases.
Also the title (and conclusion), suggest that many more people in this one region actually have had or have the virus, meaning it is more contagious than previously thought. But also that because there are actually more who have had it and survived, they posit the virus itself is not as deadly. Did I get that right?
Not sure if you can take the actual percentages and simply apply the new formula to other regions with varying demographics.
Lastly I’m suspicious of the accompanying clip at the end when the Dr. announces we can get back to normal sooner now.
Just trying to sort out all the incoming data, with a critical eye. I’d love to believe the virus isn’t as fatal as previously thought, but I also don’t want to learn that this virus is ever more contagious therefore more difficult to mitigate.
I welcome others’ thoughts. All data is important, and research accordingly....just want to ensure I’m “sifting the gems”
I agree with all your comments/questions. One cannot apply stats from the Stanford study on other area directly without doing similar sample testing. There is a difference in how much testing is done in different arias. However, I would assume that overall conclusions would be similar - more contagions and less deadly.
I have to agree with GG - as I understand it there are next to no antibody tests for Covid-19 that are guaranteed to be correct. So far more detail about the tests is needed, it is said the local testing done here was with a test that measures coronavirus in general - and there are a lot of coronaviruses.
OTOH - this probably parallels some small scale testing done in a local valley here which was particularly badly affected by Covid-19 where they suggest that at least 49% of the population show antibodies to coronavirus. If that is correct - then it means it has spread far further than thought AND a lower percentage of the infected died, the same as Ioannidis is saying. The man has a reputation for being unorthodox - he could well be right but it will require much wider testing across more than just one county to confirm it. That's how science works.
However, just because one area has had a high level of infection doesn't mean that that applies generally. Without a high level of infection and development of antibodies across the whole country there can't be that precious commodity "herd immunity" at any level. But even more important at present is that there is no idea at all of HOW LONG the antibodies persist at a level adequate to protect from re-infection, if at all. They may persist for 3 months, they may persist for 3 years, immunity may not develop well in certain groups. SARS-CoV-1 showed peak immunity developing after a few months that then lasted for about 4 years - just as well as its fatality rate was far higher at 80-90% I think. But other coronaviruses only develop antibodies that last a few months or up to a year at best.
Until you know all that you cannot say a return to "normal life" is safe. If it is so contagious - then lifting all restrictions immediately will just result in it all starting up again and a second wave across regions where the infection rate currently is lower. However you look at it, in absolute terms, large numbers of people are becoming seriously ill, even dying. You can't yet assume that people who had a low viral load when infected won't have it again even if they did produce antibodies. There are a lot of us who were shielding to avoid getting it this time round - we remain at risk until there is a functioning vaccine, without which the likelihood of there being effective herd immunity is very unlikely.
The problem is when large numbers of essential workers become ill at the same time, the whole point of the restrictions was to slow that peak down so the various services were not overloaded - not just the health services but also delivery drivers, rubbish collectors and producers and retail workers in certain essential areas like food and PPE supply. There is a limited number of experienced truck drivers, farm workers and so on - just as there are limited numbers of doctors and nurses - and ancillary staff such as paramedics, physios, hospital cleaners, porters, lab staff and they can none of them be perceived as disposable under any moral code nor replaced with the click of your fingers.
It is a start and something that needs to be confirmed - but the duration of any immunity must also be established. That takes time for obvious reasons.
GG I have no idea what you are referring to as " tests not been validated nor calibrated". If you mean how it applies on different areas, then I think I answered that in comment to PMRCanada, that one cannot apply stats from the Stanford study on other area directly without doing similar sample testing. There is a difference in how much testing is done in different arias, different demographics, etc.
PMRpro-I trust that Stanford university had adequate knowledge and proper testing. If you read stats carefully it states that " Under the three scenarios for test performance characteristics, the population prevalence of COVID-19 in Santa Clara ranged from 2.49% (95CI 1.80-3.17%) to 4.16% (2.58-5.70%)." NOT as the study you have compared it to of 49%! The point that they were making is that it is 50x higher then what confirmed cases in the same area.
As far as return to "normal life" we can all speculate what is the best way to do that. Second wave is probable in case of removing restrictions in every scenario that I can think of, so one should be smart about it to not overload hospitals. Perhaps we can learn something from how certain countries like Sweden or Japan has chosen to balance between shutting down economy selectively rather then completely and control of the spread of the COv-19 virus.
You probably need to catch up on Sweden - whose cases are increasing, especially in care homes, and there is criticism developing. The incidence in the local valley WAS much higher than the confirmed cases - the same point you were making. However - in order to return to "normal" without a second wave would require an incidence of north of 60% throughout the population and probably more like 80%. One small town in Italy did test everyone - and discovered that a high proportion of the people who tested positive had few or no symptoms at all and the rate of infection was high anyway. It has been assumed by many here that at least half and probably more of infected patients have no symptoms, until these figures are identified with accurate antibody testing nothing can be said about either incidence or death rates.
Universities don't always have control of what and how a member of staff publishes. And this site you have linked to is a conspiracy theories spreading website operated by Michel Chossudovsky's Centre for Research on Globalization which has been implicated in spreading pro-Russian propaganda. So I'm far from sure that I'd take anything it publishes too seriously.
I am familiar with Sweden and higher incidents of infection (initially), and that is what to be expected. It is criticized by others because they did not implement "home arrest" model, prevalent in the rest of the Europe. It is not clear today - we will not know which model is better until this pandemic is over. One thing for sure, shutting down complete economy is not a long term solution. Remember the object is to flatten the curve, and how it is done is up to each country. Whose solution is best -we don't know at the moment.
I do follow Michel Chossudovsky's Centre for Research on Globalization not because he has some articles that lean towards conspiracy theories territory, but because he also publishes articles that have valid points and would not be published by corporate media. With all due respect, it is better to evaluate message on it's merit, rather then smear or kill the messenger, which is what you are attempting to do. As far as "pro-Russian propaganda", what does that have to do with subject at hand? Just a distraction or what?
Well, nick, what it means is that the test needs to be detecting the right thing, and that the results of the test need to be accurate within an acceptable tolerance, not just in the lab but out in the field. Even a well designed test can give false results if the test manufacture, distribution, sample collection, transport and processing specifications are not met. With such a small sample, one glitch anywhere along the line can skew the results when projected out over a much larger population.
So essentially, what you're seeing here is a test of the test.
Here's a link to Stanford's caveats regarding the test:
Additionally, there are several articles on the net discussing likely statistical errors in projecting the initial results of a relatively small sample over the entire population of the counties targeted, but notably, none that I have found have been posted by reliable academic and scientific sources. Larger studies are underway in California and elsewhere around the US.
So we'll have to wait and see what turns out to be true.
But if you're ready to go out and risk contracting the virus, by all means, go ahead.
well gg, your edited response is much more detailed and explains your reservation on test results. However, here is my response.
Sample size - As far as comment on the sample size, there are several ways to determine what is adequate sample size. Quick calculation shows that sample size of 3330 people would give close to 95% confidence for selected 2mil population. In my opinion it is far more important how the sample is picked, who was selected to participate in the study.
The caveats regarding the test are CDC's not Stanford. Ironically it is CDC contamination that screwed up COV19 testing for US in the beginning, but hey that is another subject all together.
Lastly, I detect some sarcasm in your last sentence. You probably forgot that I live in Japan where ALL respect rules and behave like adults, so we don't have to be under "house arrest". Always felt that in US asking people to follow rules is like trying to herd the cats. BTW, just came back from 30min walk before this post. I still do mountain biking 2-3 times a week.
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