CV: Stanford Antibody study results are out ...
Figured this was worth a new thread - the first truly rigorous and large CV antibody test results from anywhere in America.
This is Santa Clara County, the SF South Bay. 3330 residents tested in a county of about 1.9 MM.
Key takeaway - estimated that 2.49%-4.16% of the population there has been infected by CV by early April (the study was done on April 3-4) already. That prevalence estimate represents a range of 48,000 to 81,000 people infected in Santa Clara County by early April, which is 50x-85x the number of actually confirmed cases.
Link to the paper:
https://www.medrxiv.org/content/10.1101/2020.04.14.20062463v1.full.pdf
Of course, that is just Santa Clara County, but it gives us another estimate of the ratio between actual and confirmed cases. I've always been pegging that number at 10x-30x. This ratio is obviously larger than that.
More and more antibody studies to come in the time ahead. I think a similar Stanford study conducted down in SoCal (as opposed to NorCal) is next, and should be out within days.
April 17th, 2020 at 12:59 PM ^
Apparently of 215 pregnant women in NYC screened at 2 hospitals, over a two week period, 33 women tested positive and only 4 women showed symptoms. So the virus could be more widespread than we think. Really want more widespread antibody testing
I would STRONGLY caution against making too much into this study. This WAS NOT a random selection of population that they tested. They recruited people through Facebook. Which would indicate that they were probably more affluent and healthier than average. And that could mean that actual infection rate could be significantly more (or even less).
While this is better than just flying blind, let's not jump to too deep of a conclusion based on a single study.
I suspect there will be some interesting critiques of the selection method. Your point about demographics of facebook users is interesting. I actually thought they might get an overestimate because people most interested in volunteering might also be people who had a stronger belief that they’d had it. This would be especially true if they either got their individual results or even if they had an expectation that they might get their individual results.
I'm not an epidemiologist either but I do own a calculator. Right now the death rate on reported cases is really high in the US - about 5%. But if reported cases are understating actual cases by 50x, that makes the death rate 0.1%, or exactly in line with the....wait for it....SEASONAL FLU. I've been a Democrat all my life but this is making me seriously consider voting for Republicans. What a joke this entire thing has been - foisted on us from the start by the NYC media hellbent on getting Trump. I'm going fishing on the Chattooga River tomorrow and trying to forget this con job. The ruse is gonna be up in a few weeks anyway.
April 17th, 2020 at 12:03 PM ^
Interesting stuff. Slightly more prevalent than was thought.
Also throws out the idea that the bay area already has heard immunity, which some researchers thought based on a dec respiratory death spike.
EDIT: yes slightly. People with knowledge in this field have been assuming we are missing nearly this many cases and it is already accounted for in most death rate estimates.
April 17th, 2020 at 12:20 PM ^
Slightly?
April 17th, 2020 at 12:25 PM ^
Well yes, kind of. Basically anyone knowledgeable has been saying the number of real cases is likely much much higher than has been reported. That goes for basically anywhere.
April 17th, 2020 at 12:28 PM ^
Sure. I have seen 10x or so thrown around. This is nearly 100x.
That is a big difference. It makes the risk of death from the disease much lower.
April 17th, 2020 at 12:43 PM ^
Most people had been going with ~x30 or so.
This one study suggest x50 or so (which is great news) but it is one study in one location.
April 17th, 2020 at 12:44 PM ^
I’m not an expert, so consider this a question. This data means that both the infection death rate is lower than previously thought, and also that more people have been infected than previously thought. Does that imply that the disease is more contagious than previously thought? So the % to reach herd immunity is also higher than previously thought?
April 17th, 2020 at 12:51 PM ^
I'd argue that these numbers are just about what experts would expect. That'd mean either its slightly more contagious or it arrived slightly earlier in this area than thought (but not months).
Side note: PhD in physiology but getting negged in this thread,
yep. strange how people can't have open minds, even on a developing subject like this.
April 17th, 2020 at 12:47 PM ^
It doesn't really. The mortality rate for infected is lower because the denominator got much bigger, yes. But it also means the disease is more infectious than we thought before.
Also, AFAIK this test doesn't assess the concentration of antibodies or future immunity. It's entirely possible the high number of positives from this study don't really correlate with people that really had COVID19, but simply came into contact with it enough for an immune system response. These may still be subject to getting more severely sick if exposed differently again.
Yes "Klima" , but while it appears to make the overall death rate quite a bit lower, it doesn't change the facts that 1) anyone over ~50 has a significantly higher risk of death and that risk shoots much higher as one gets older, even if you are in good health;
2) those with immunological problems, regardless of their age, are at a much higher risk;
and 3) so are many others, no matter their age, for a lot of unknown reasons.
I'm in my mid 60's and have a couple other known risk factors. Each of you have your own reasons (even if you try to dismiss them) for exercising reasonable caution, even if for no other reason than to limit community spread.
Let's hope and pray ? (dependant upon your beliefs) that our top scientists/doctors/health officials get a fact-based handle on cures/treatments, immunities/vaccines, everything Covid-19 related, and that our politicians pay proper attention before making rash and/or irrational decisions that negatively affect us all.
Rob,
Let's put this in perspective. Yes, the overall rate is based on different rates for different people. But, that is always the case.
The risks for being hospitalized from this disease (and dying) are highly dependent on two factors, age and obesity.
Young, health are not at nearly the same risk. It is extremely rare even for a disease that is overall, very mild.
Think of it this way, if the overall fatality is .3% and the vast majority (80%) of those hospitalized are obese or over 65, that means the rate for young healthy people is much much much lower.
It is not a random killer. It is heavily weighted.
THE IMPORTANT PART is that the same thing can be said for most viruses and diseases. A severe cold can rip through a nursing home and kill 8% of residents. The flu very rarely kills younger healthy people (but it does) and it is very dangerous for the elderly population.
I think elderly and obese people should be extra cautious, but they should be extra cautious of any infection. This one is new but doesnt look that much more fatal.
The evidence is coming in that this is similar in its effect to many other existing risks.
Thanks for your well-reasoned response, though I have serious doubts about the infection rate until we have a lot more scientific data to accurately rely upon.
I do understand and am in favor of getting the country reopened, getting the economy back on track, getting certain unreasonable restrictions reversed.
My biggest concern, though, with all of this is that EVERYONE, from the White House on down, must realize that we're in this together and can't let our guard down if for no other reason than that this virus is so very contagious.
Super contagious. That is exactly what this study shows too.
But that is very comforting because it also shows it is much less severe risk if infected.
But contagion doesn't change the risks associated with getting infected.
Literally 40% of the US population is obese (over 7% severely so). Another third is overweight. Nearly half the country has heart disease.
There a A LOT of people at increased risk.
Good luck to you BTW. If you are over 65 take extra, extra precaution as things open back up.
My parents (in their 80s) living in a nursing home. I wont go see them until there is a rapid test that shows I am not infected as I walk in to see them.
It will be hard on the most vulnerable. We should always be looking out for them, now and anytime.
It really depends on your definition of similar
https://www.cdc.gov/nchs/pressroom/sosmap/flu_pneumonia_mortality/flu_pneumonia.htm
This link provides historical flu deaths by state
https://www.worldometers.info/coronavirus/country/us/
This link provides current US death totals
You can play with the data however you want, but picking 2018 (which I think is widely accepted as a bad flu year). New York State had 4749 flu deaths. They currently have 16,736 covid desths and the number is still increasing. That is already 3 times as many deaths and quickly approaching 4 times. Obviously New York has been very hard hit, but you can’t just wave away those numbers and suggest it isn’t much more fatal.
April 18th, 2020 at 10:33 PM ^
NY State also had about 44k deaths to cardiovascular disease, 35k deaths to cancer, 7k to lower respiratory disease, and then about 4k-6k each of accidents, stroke, flu/pneumonia, Alzheimer's, diabetes, hypertension. It will be interesting to see how much overlap there turns out to be. That is to say, will the actual death rate be larger, smaller, or relatively similar to years past.
The study is further evidence that the virus, while bad, is nowhere near as deadly as the projections that prompted this extreme and devastating lockdown said it would be. If you feel like you need to take special precautions, then you should be free to do so, but don’t require everyone else to permanently destroy their jobs and businesses to join you.
April 17th, 2020 at 12:30 PM ^
Deleted
April 17th, 2020 at 12:03 PM ^
Not nearly enough for herd immunity, but it helps give us a better idea of the CFR of the virus...
April 17th, 2020 at 12:06 PM ^
Interesting article here relating to virus prevalence, testing, etc:
April 17th, 2020 at 12:06 PM ^
What is interesting to me is that now some are saying that the strain mainly going around on the West Coast is similar to cases seen in Asia, while the one largely seen in the Eastern US (including Detroit) is similar to cases seen in Europe. No clue if one is more potent than the other, but makes sense given volume of transatlantic travel to the East Coast that had no restrictions til Mid March.
Detroit in particular, being a Delta hub, had daily flights from places like London, Paris, Amsterdam, and Frankfurt even as flights from Asia were being canceled, not to mention, it was one one of the repatriation hubs post travel-ban
April 17th, 2020 at 12:21 PM ^
Flights from Asia weren't canceled. It was just a ban on travelers who had been in Wuhan in the previous 14 days, and even then US citizens were not stopped.
April 17th, 2020 at 12:25 PM ^
Imagine how fucked we would have been if the auto show had taken place at its usual time.
April 17th, 2020 at 12:38 PM ^
Great point, which I hadn't even considered. That would have been a super spreader event on steroids.
I read that at the time the issue was exploding in Italy that the Germans had identified three different sub-strains. They were tracking specific trails, one that went from China to a German Webasto auto parts plant to Italy and two others in Italy. The details are beyond me but it appears that the experts are looking at deeply into the details of the trail.
April 17th, 2020 at 12:17 PM ^
This is really interesting and the USC study with LA residents should be coming out soon too. I'd love to see more of these.
April 17th, 2020 at 12:17 PM ^
It would seem that population density and weather would be significant factors that influence spread. NYC has a very high population density and they were struck during the winter when people spend most of their time indoors, thus suggesting considerably higher rates of spread which is what we have seen in NYC. I'd bet that serological testing results would be higher in NYC than in the study in the OP.
April 17th, 2020 at 12:23 PM ^
FWIW, while not to be confused with random serology testing, there are indications that a higher % of population in NYC has been infected. Here is one piece of supporting (not conclusive) evidence where they tested all pregnant women coming into a couple of hospitals. Again, not a random sample, and probably not high enough numbers, but interesting nonetheless:
https://www.nejm.org/doi/full/10.1056/NEJMc2009316
Unless there is something incredibly strange going on in New York that is causing people infected to die at a much higher rate, the percentage of people infected has to be much higher. Average deaths per million in New York State is 853. For the United States as a whole it is 107. That suggests the percentage infected in Mew York is about 8 times that in the rest of the country. In New York City, the numbers are even higher about 1058 per million (note that NYC website has three numbers for deaths - I used the middle which is what they say they report to New York State.
April 17th, 2020 at 12:20 PM ^
Well if the infection rate is 50-85x that would imply that the mortality rate is actually much lower, which is good. However, there are lots of press reports the last few days of "deaths at home" which are supposedly not being counted against the coronavirus numbers. So who knows? This is good information, but there is so much disinformation being spread that the fog of war with this thing is thick. People are making the sacrifices, but the noise is annoying.
April 17th, 2020 at 12:23 PM ^
This is another point that a lot of people keep misrepresenting (I'm not saying you are, just in general). To me, the key data point is the death rate of confirmed cases, as those are the people sick enough to seek and obtain testing. We'll likely never know the full extent of infection around the world.
"key point is the death rate of confirmed cases".
i think that is a meaningless point right now. that is basically just the death rate of really sick people; those who sought help. you have to get the entire population (or a significant random sample) tested for the death rate to matter.
April 17th, 2020 at 12:37 PM ^
The “deaths at home” issue is troubling on many levels. No doubt many many of those are C19 related. What’s unfortunate, is that it’s possible that people having other issues are afraid of seeking care right now as well:
“The most concerning possible explanation is that people stay home and suffer rather than risk coming to the hospital and getting infected with coronavirus.” Really unfortunate if this explanation is true.
Key message from the article: “Meanwhile, the immediate message to patients is clear: Don’t delay needed treatment. If fear of the pandemic leads people to delay or avoid care, then the death rate will extend far beyond those directly infected by the virus.”
April 17th, 2020 at 12:53 PM ^
In 2017, 13.5K NYCers died at home --- which works out to roughly 250 per week.
That's sad --- but people slip on stairs or get sick and can't get to a phone to call a hospital. Folks die at home even in normal times.
I know NYC is now counting ~ 1000 home deaths as due to COVID, and that's possible. But I wonder how they are counting those given there is already a baseline # of at-home deaths.
https://www1.nyc.gov/site/doh/covid/covid-19-data.page
NYC cites three different numbers. Confirmed 7,563. Probable 3914 (I assume that is on top of the first number. They also have a third number 8893 which they are reporting to New York State. That seems to include only a portion of the probable deaths. I could not find any good descriptions of the difference in methodologies but ai did find one quote that suggested the 3914 deaths was based on increase in at hime deaths relative to previous years. Presumably the lower number reported to New York represents an attempt to verify the deaths were from coronavirus by symptoms, but this is clearly speculation on my part.
April 17th, 2020 at 12:22 PM ^
thanks, interesting stuff
not sure if this changes my thoughts in anyway, but it's interesting
April 17th, 2020 at 12:26 PM ^
About ten days later, the death toll in that county was 60, correct?
So, what is the IFR or CFR?
April 17th, 2020 at 12:37 PM ^
I'm no math genius so maybe I'm doing it wrong, but 1,928,000 people in Santa Clara using the low end unweighted prevalence of 1.5% you get just under 29,000 infected with 69 current deaths is about 0.24% CFR
April 17th, 2020 at 12:56 PM ^
Assuming that we aren't missing deaths AND that all with antibodies are prevalent.
The antibody test was two weeks ago. Any future deaths would probably go up, but so would future infections. Both the numerators and denominators would go up.
Not likely to be missing a lot of deaths in that county, but there is lots of variable in the potential infected number too. Wouldn't matter much.
Good point, edited to reflect that!
April 17th, 2020 at 12:28 PM ^
Yesterday my wife was diagnosed with Covid. She is having a he'll of a time. She hasn't left the house in 45 days so she must have gotten it from me and one of my shopping trips.
Looking back, 2 weeks ago I had a period of 3-4 days where I felt someone was squeezing my chest. I joked it was CV with my wife. But no fever, no cough, just pressure and fatigue. Doc thinks that's when I unknowingly had it.
I want an antibody test badly to confirm. I want to know I am immune so I can go into the community and help people. Its so frustrating.
April 17th, 2020 at 12:39 PM ^
Please take care of yourself and your wife. I dearly hope she gets better soon.
Thanks Cumstein. She's not getting better, but she's not getting worse. Doc gave her a prescription for a cough suppressant pill so fingers crossed it works and we both get some sleep tonight. She is in good spirits considering...but to give everyone an idea what this is like last night she coughed CONTINUOUSLY for 3.5 hours. We had a humidifier going and tried all sorts of stuff. NOTHING stops the coughing. Its brutal.
that sucks dude
my company has an antibody test in the works and tomorrow we are shipping vials we made last weekend to the East Coast for distribution (if the FDA approves today). This will help treat severe cases. Can't say the name, but there is hope on the way. I was blessed to be able to help develop the filling process over the last month and we are ready to start kicking out 100's of thousands of vials next week.
Hopefully she's not a severe case.