10 times as many cases as reported, is this accurate?

On June 25th, CDC Director Robert Redfield announced that the actual number of cases in the U.S. is ten times greater than the reported cases, by their best estimation. This information was based on results from antibody testing. I was skeptical. The number was much higher than I thought. Over the next few weeks, experts and officials continued to use this number, so I began to believe that the information was accurate. Here is a link to an article from June 25th: CDC estimates 10 times as many U.S. coronavirus cases than have been reported

Other Studies
The reason I was skeptical was because other antibody studies that have been touted by the media turned out to use heavily biased sampling. I read about two of them. The first was from Chelsea, Massachusetts, where they took samples from people who were out-and-about on the street. The second was from New York, where they sampled people in grocery stores. By the nature of infectious spread, those people who are out-and-about more often are more likely to contract this disease. And people who are out more often are much more likely to be included in these samples than those who are out less often. My opinion is that the sampling in these studies was so biased that the results are worthless.
Chelsea article: One third of participants in Massachusetts study tested positive for antibodies linked to coronavirus
New York article: New York antibody study estimates 13.9% of residents have had the coronavirus, Gov. Cuomo says

The New Study
A few days ago, someone posted a link to the new study that CDC Director Redfield was referencing. The study was published online on July 21st. I have had a chance to look over the study and I’ve come to the conclusion that Director Redfield was wrong in his June 25th statement. There were not 10x the number of actual cases than reported cases on June 25th and there certainly isn’t now.
Article: Coronavirus Infections Far Exceed Reported Cases, CDC Says
Study: Seroprevalence of Antibodies to SARS-CoV-2 in 10 Sites in the United States, March 23-May 12, 2020
CDC Dashboard with results: Interactive Serology Dashboard for Commercial Laboratory Surveys

Random Sampling?
“We obtained convenience samples of deidentified residual patient sera collected for routine screening (eg, cholesterol screening) or clinical management”. Did some people who were more cautious skip a routine visit to the clinic because of coronavirus? Many of these patients have chronic health conditions (thus the need to go to a clinic). Are these people more cautious overall because of underlying health conditions? The study also says, “It is possible that specimens were drawn from patients seeking care for suspected COVID-19 symptoms, potentially biasing results, particularly in settings such as NY where disease incidence was higher.” So it’s hard to say for sure how biased these samples are. I think there is a very slight bias towards positive test results, but nowhere near the bias in the other studies.

The Date Range
The date range is the biggest issue for me. The samples were taken between Mar 23 and May 12, depending on the location. For instance, NY metro samples were taken from Mar 23 to Apr 1. The average seems to be about mid April. The results were compared to the number of cases at the time the samples were retrieved. But the testing capacity in the U.S. has been increasing since then, thus more cases are being detected now than they would have found back in April. So, while the ratio of actual cases to reported cases may have been 10x back then, it’s surely not 10x now, or even at the end of June when Redfield made his statement.

According to 91-divoc.com, The U.S. was testing about 450 ppl per million in mid-April. By the end of June, about 1200 per million and now it’s 2500 per million. So five times as many tests are being given now than at the time of the study. That doesn’t mean 5 times as many cases are being detected because a lot more asymptomatic people are being tested, but there are certainly a lot more. Maybe double the amount of cases are being detected? That would mean the 10x number no longer applies.

For these reasons, I believe CDC Director Redfield was incorrect. In my non-expert opinion, the actual number of cases is only about 4x to 5x the current reported cases. What do you think? Are there flaws in my reasoning?

Re. sampling:

You are absolutely correct to be conscious of the limitations of convenience samples. The CDC is also engaged in the more rigorous work of community level seroprevalence survey collection which uses systemic sampling, but those will take longer … they are not conveniently on hand.

That said in terms of antibody positive numbers/confirmed infection numbers my WAG is that any selection bias would actually go the other way in this case, for exactly the reason you stated, that these people may be more cautious than the general population overall because of underlying health conditions, so therefore less likely to be exposed, and also presumptively less likely to have remained asymptomatic or mildly symptomatic when infected. That’s the opposite than the convenience sampling of people out and about more on the street or at the grocery store.

We can also look to other countries. (Did here.) Spain had about 0.5% of the population with reported confirmed infections and 5% antibody positivity, so 10x. Sweden was running 59x more. The U.K. mid-April was up at 99x more (but had run over 30% positivity rate).

Re. Date Range:

A reasonable point which can be further supported. The key metric for apples to apples is the positivity rate. Positivity rates in that date range across the country were running 11 to 20%; now they are running 8 to 9%. The generally accepted principle is that higher positivity rates means more that were never diagnosed.

Then however there is the issue of who is getting infected now, the shift to a much younger population, who tend to have mild to asymptomatic infections much more commonly. It is reasonable to suspect that the tested group is barely scratching the surface of the numbers of these individuals who have no to minimal symptoms.

But then there is the bigger wrinkle: point prevalence of antibody positivity may dramatically underestimate past infections. We know that some number had antibodies which declined over time (which does not mean they are not, or are, immune), and some had infections with strong specific T-cell responses without ever having had an antibody response detected by the tools used. Small studies done so far (much harder to do than antibody ones) but so far they suggest that antibody positive results may miss at least half of those with even fairly recent infections.

So could the actual number be only 4 to 5x? Sure. Could it be 20 to 30x? Sure.

‘Worthless’ for what purpose, though? If it’s to answer the question ‘What percentage of the entire population has been exposed?’, then sure, you’d want your sample to be fully representative of the entire population. But what we are really getting at here, I think, or at least trying to, is whether exposure levels are so great as to approach some level of herd immunity. That’s the ‘purpose’, in other words, of pondering this question. And the critical point, then, is that those who are so isolated that they are no longer represented by a random sample of people out on the street or at a grocery store have also removed themselves from the population that is susceptible to the virus’s spread.

Now, if there is some huge number of them (which I kinda doubt), and let’s say they all decided all at once to rejoin the pool of susceptible, then presumably they would give the virus another mass of targets. But the implications of a prevalence far greater than reported, if it were indeed true, would of course remain.

If it is indeed that prevalent - 45 million infected Americans - then one questions whether some precautions are even worth it or not. You almost can’t avoid Covid anymore. Sure, one should wear masks, distance regardless, but you’ll be interacting with Covid people all day long.

Not all infected at this moment, have been infected, most resolved.

I find it really hard to imagine this not being the case, when I read a number of similar-sounding news articles. Like the recent one about the kids at a camp, where something like 75% tested positive. The present outbreak in Melbourne, where they thought they had it under control. Vietnam with a new spread (that while not yet wide, seems to getting a little wider by the day) after three months with nothing. And of course, the way it touched most everyone on those cruise and navy ships.

I just wonder what the people who advocate for hard-core avoidance see as their endgame. To me it’s starting to look more and more like the responsible thing to do would be to let everyone under 30 or so get exposed now if they can. I read one expert who, when asked about New Zealand’s approach, said it was almost like not vaccinating your kid.

You “read an expert”. Really.

You are characterizing the U.S. clusterfuck as though it’s a sensible strategy to reach herd immunity as soon as possible. Sure, it’s a de facto experiment in the dynamics of the virus when it’s completely out of control, it seems that we are on course to discover the “natural” path to herd immunity without vaccination. But the cost of this experiment has been 160,000 lives, and that number will double in the next 6 months.

Do you know how many have died in New Zealand? 22.

And in 6 months we could have an effective vaccine, with enough doses to innoculate at least the elderly and vulnerable soon after, reducing mortality to almost nothing.

So the “endgame” is 22 deaths rather than 300,000.

And do you want to place bets on the proportion of the population in each nation who are antivaxxers or conspiracy theorists who will reject a vaccine?

Are you implying that none of us should believe what the experts say? I guess that’s part of this whole mess.

I’m obviously saying that your assertion about NZ was utter nonsense. I don’t believe any expert said this. Provide a cite.

Or at least paraphrase the arguments and reasoning of this “expert” that you found convincing, rather than ignoring the substance of what I posted in response.

…holy fucking shit.

…as Riemann suggested, can you cite this supposed expert?

Because there have been plenty of experts who have been involved in the New Zealand response, including Professor Michael Baker, and Associate Professor Siouxsie Wiles, who have advocated strongly and publicly for the New Zealand strategy. Their voices have been at the forefront of the debate, advocating strongly for elimination.

In Iceland cases have started to go up after having been quite static for a while. But they aren’t seeing an explosion, because the numbers are still low, manageable, and contact traceable. And it wouldn’t be that different here. If someone were to slip through our net it would be much easier to get under control here with our low numbers than it would be otherwise. I can’t see a reason to compare our approach to “not vaccinating your kid.” That doesn’t make any sense at all.

Here is the link. I don’t know anything about the source, nor this supposed ‘theoretical epidemiologist’ at Oxford (but neither do I about most any of the other supposed experts I read).


I think she makes some thought-provoking observations, but I’m certain they won’t be well received by either one of you.

Here is the quote:

‘If it turns out that the rest of the world, through herd immunity or vaccination, manages to reduce the risk of infection, then what New Zealand will have done would be tantamount to not vaccinating your own child. Just waiting for everyone else to vaccinate their children and then go “ok it’s all safe now”.’

One of the problems with this theory is that it assumes if you get the disease and don’t die - it’s no harm, no foul.

A young person that works for the same company my nephew works for got the disease recently. They work for a concrete and stonework company, the kind of place that paints American flag designs on their trucks. They stayed open and almost fully operational during the initial lockdown - as did most companies that weren’t dealing with the general public at a retail level. They were actually good about safety and gave paid furlough to their high risk employees- mostly the older guys but they included my nephew because he has a newborn child.

But now 2-3 months later- they had to close one of their two plants for over a week because of the sick employee and they had to sent a couple dozen people home to quarantine. This is a much larger economic disruption than they had during the original lockdown. And apparently the kid was pretty sick, no danger of dying but not “a few days of sniffles”, it was two weeks of something worse than the worst flu he’d ever had. And an older coworker of his did get sick and ended up hospitalized although he survived.

That’s a lot of economic disruption for one sick kid, and a lot of harm even though no one died.

Now, there is a very small, very evil, corner of my brain that WANTS or government to ban masks and distancing and force everything to open at full capacity. Because it would be so incredibly devasting for the Republican Party that they would be crushed into irrevelance for decades and that might be an ultimate good -kind of like how the Black Plague destroyed the feudal system.

But the bulk of my brain, the good part wants to keep as many people alive as possible.

And one of the problems with this theory is that it assumes the masks and distancing are ‘defeating the enemy’. Or that it presumes that it’s a ‘war’ we have to fight. One of the most thought-provoking passages from the professor’s interview, to me, was this:

Alastair: It’s interesting that you mentioned folklore. In the West we have this idea that we want to eliminate disease – that there’s a heroic figure who intervenes and then resets the social order. In some parts of Asia there is a very different approach, it’s more about accommodating yourself to the natural world, and cultivating a more holistic view of how you live with disaster. Things like lockdown have their own folklore.

Yes, that seems to be much of the language of it. It’s semi-religious, actually.

As you say, I’m astonished at two things. One is the bellicose language used with respect to the virus, which does point to this desire to annihilate, which seems to me strange. Maybe it has something to do with coming from an eastern tradition, but I’d like to think it’s strange because we live with infectious diseases. We do accommodate infectious diseases into our social contract, really. We know that this is a threat we have to deal with.

The other interesting issue that I’ve suddenly realised with this particular threat, is that people are treating it like an external disaster, like a hurricane or a tsunami, as if you can batten down the hatches and it will be gone eventually. That is simply not correct. The epidemic is an ecological relationship that we have to manage between ourselves and the virus. But instead, people are looking at it as a completely external thing.

The endgame is to avoid getting a disease that might cause lifelong organ damage, pain, and brain problems. Here’s an article that talks about some of the long term problems. The outcome is not a recovered or dead. Maybe most people are fully recovered in a month, maybe some take six months, maybe some more a year, maybe others never get back to 100%. We don’t know, but we do know there is lingering damage post recovery in many people. We can’t predict where people will be on the asymptomatic to dead spectrum. We know about risk factors for the bad end, but low risk is not no-risk. Lots of young people have other risk factors, lots of young people without obvious risk factors go through a real bad time, or even die.

Heart damage has been found in people recovering from symptomatic cases of Covid. We do not know how long that heart damage will last. We do not know if it will heal. We do not know how much of a problem it will be in the future. There is (probably) nobody in the world who is one-year post-recovery, let alone enough people to make a suitable study sample.

The endgame is to avoid a disease that might change your life permanently. Avoid it like New Zealand did, by closing and driving the case level way down, so the risk of getting infected is very low. Try to stay safe long enough for a vaccine or effective treatment to come out. Maybe there will never be a vaccine, but there probably will be. Maybe in six months, maybe in a year. Until then minimize your risk by wearing a mask, distancing when possible, and avoiding unnecessary risk.

And what’s with the people who complain they might need a vaccine booster every year? Trade masks, distancing, isolation, and economic slowdowns for a once per year needle prick? Yes, sign me up.

That’s a goal not an endgame.

The endgame possibilities…

successfully maintain suppression level actions at whatever cost until a safe effective vaccine has been widely distributed to herd immunity levels, and maintained as such forever, if such occurs, and if not then continue such forever.

Or at some point fail at such suppression, possibly at the worst possible time.

Or somehow gradually reach whatever is herd immunity preferably weighted to those least likely to experience the worst morbidity and mortality and at the least poor times.


…I rolled my eyes when I saw that you were citing Sunetra Gupta. As in “Universal Flu Vaccine” Sunetra Gupta, as in May Covid-19 is on its way out Sunetra Gupta. She takes a contrarian view, and doesn’t have a great track record for getting things right. We can look to places like Victoria in Australia or Iceland where the numbers got close to zero before they started to go up again. The numbers in those places aren’t going up in a way that is out-of-step with other outbreaks, things aren’t spreading like “wildfire” as one would expect if Gupta’s theory (that “we may already have herd immunity”) were correct.

In fact if we look closely at her statement we can see that its nonsense. If it does turn out the rest of the world manages to “reduced the risk of infection” via “vaccination” then why would New Zealand not also vaccinate? Why would we wait? We wouldn’t “wait for everyone else to vaccinate their children and then go ok it’s all safe now.” We would vaccinate at the same time as everyone else.

Well, I’m imagining it’s fair to guess, given your take here, that I’ve read through more of her articles recently (than have you), and I’ve read the published studies, and I’ve watched her interview with Unherd – and I think you’re not characterizing her viewpoint fairly. I think the results we’re now seeing do match the ideas she put forth, at least in principle. And it’s very much worth considering that their initial published study was not meant to be an indication of the way things definitely are or could be, but rather, was meant to be a ‘best-case’ counterpoint to the ‘worst-case’ model that really got the lockdowns started. She pointed out, at the time, how both models could fit the past and presently observed data equally well. Watch her interview and you’ll hear her say that she imagines the real truth is somewhere in between. But I don’t think anyone now believes that 500,000 Brits would have died by now if not for mitigation efforts.

You and I will each have our own perspectives and beliefs about what the reality is, the thing that the models are guessing at, but I think if you were being fair you would have to say that there is a good chance she’s not wrong. Saying we already in hard-hit places have some form of ‘herd immunity’, after all, is nowhere near the same thing as saying we have ‘eliminated’ the virus.

…so we’ve gone from “I’ve read one expert who said” to “I’m intimately acquainted with the entire body of Sunetra Gupta’s work.”

Okay then.

Explain how Victoria or Iceland match the ideas she puts forth, at least in principal.

Why not? The total is nearly at 50,000 now. Excess deaths were “7.55 per cent higher this year through the end of May, compared with its five year average.” Higher than anywhere else in Europe. And people are still dying. And places are going to start opening up. So 500,000 with no mitigation doesn’t sound outlandish.

I think its very fair to say there is a very good chance that she is very very wrong. And I’ve explained why.

Her statement is nonsense. Why would we not vaccinate if a vaccine were available?

There is no evidence that hard-hit places have some form of herd immunity. And nobody is saying that having “herd immunity” is the same thing as “elimination.” We have eliminated Covid-19 from New Zealand. That isn’t herd immunity. And there isn’t a place on earth that has some form of herd immunity. Not even close.