Hauke Hillebrandt

[Question] Preprint says R0=~5 (!) /​ in­fec­tion fatal­ity ra­tio=~0.1%. Thoughts?

• Hauke Hillebrandt 20 Mar 2020 15:19 UTC

  1 point

  in reply to: ErickBall’s comment on: Preprint says R0=~5 (!) /​ in­fec­tion fatal­ity ra­tio=~0.1%. Thoughts?

  Not sure: the Diamond Princess is mentioned in this preprint and in fact one of the authors of this preprint wrote two papers on the Diamond Princess:

  https://​​scholar.google.com/​​citations?hl=en&user=OW5PDVgAAAAJ&view_op=list_works&sortby=pubdate

  So I think they thought about this,

• Hauke Hillebrandt 20 Mar 2020 15:29 UTC

  1 point

  in reply to: Lukas_Gloor’s comment on: Preprint says R0=~5 (!) /​ in­fec­tion fatal­ity ra­tio=~0.1%. Thoughts?

  As mentioned in a comment above, one of the (pretty highly credentialed) authors of this preprint has written two papers on the Diamond Princess, and so, excuse the appeal to authority, but any argument against this paper based on Diamond Princess doesn’t seem likely to invalidate conclusions of this preprint .

  Also this squares seemingly squares more with John Ioannidis take on Corona:

  “no countries have reliable data on the prevalence of the virus in a representative random sample of the general population.”

  And that airborn-ish transmission is highly likely.

The case for C19 be­ing widespread

• Hauke Hillebrandt 28 Mar 2020 1:00 UTC

  1 point

  in reply to: ignoranceprior’s comment on: The case for C19 be­ing widespread

  If the Gupta study is true, then a rough approximation (ignoring lag) would be that it’s:

  IFR = Number of UK deaths (~750) /​ 36-68% of the UK population (66 million).

  So 0.002% to 0.003%.

  In Italy, with almost 10k deaths it would be 0.02%-0.04%

• Hauke Hillebrandt 28 Mar 2020 1:31 UTC

  1 point

  in reply to: DanielFilan’s comment on: The case for C19 be­ing widespread

  This seems pretty hard to evaluate because with a large number of published pre-prints on the outbreak, it’s not very surprising that there would be many suggesting higher-than-expected spread.

  No, this is different. I’m not just cherry picking the tail-end of a normal distribution of IFRs etc. The Gupta study in particular and some of the other studies suggest a fundamentally different theory of the pandemic.

  Presumably some of these people are hypochondriacs or have the flu? Also, I bet people with symptoms are more likely to use the app.

  Yes, but similarly there are many asymptomatic people who do not use the app. The King’s Professor seems to find this number convincing.

  Couldn’t this be explained by those populations travelling more, shaking more hands, meeting more people, etc.?

  Tom Hanks, Prince Charles and Boris Johnson don’t talk meet more people everyday then your typical Uber driver cashier etc. There millions of people working in retail. We don’t see them all having it. My theory is that they’re tested often and not that “there’s a lot of C19 in Westminster”

  Iceland has 2 deaths and 97 recoveries. I would say that isn’t good evidence for an IFR of under 0.3%.

  Crucially depends on the asymptomatic rate, which might very well be very high.

• Hauke Hillebrandt 28 Mar 2020 1:38 UTC

  1 point

  in reply to: DanielFilan’s comment on: The case for C19 be­ing widespread

  There were a few dengue in Australia and Florida where it is unusual

  Dengue “popping up in unusual places”, makes me think that it’s more likely that massive Dengue outbreaks in Latin America might have a high proportion of C19.

  One person had persistent negative swab, but tested positive through fecal samples...

  “Chinese journalists have uncovered other cases of people testing negative six times before a seventh test confirmed they had the disease.”

  This is just to lend credence to the paper that shows there had been 2 million infections in China in January.

  I find it very unlikely on the face of it that China, or any country for that matter, managed to suppress completely a disease so contagious that it’s now on almost every country on earth.

• Hauke Hillebrandt 28 Mar 2020 1:48 UTC

  −2 points

  in reply to: ignoranceprior’s comment on: The case for C19 be­ing widespread

  I’m not impressed by the comment about this paper here on LW or the twitter link in it.

  This paper was written by an international team of highly cited disease modellers who know about the Diamond Princess and have put their reputation on the line to make the case that this the hypothesis of high infections rate and low infection fatality might be true.

  I think it is a realistic range that this many people are already infected and are asymptomatic. Above I’ve tried to summarize and review the relevant evidence that fits with this hypothesis.

  But I’m not ruling out the more common theory (that we have maybe only 10x the 500k confirmed cases). I just find it less likely.

• Hauke Hillebrandt 28 Mar 2020 2:32 UTC

  1 point

  in reply to: DanielFilan’s comment on: The case for C19 be­ing widespread

  The point remains: given that some people have such a different theory, it’s unclear how many supporting pieces of evidence your should expect to see, and it’s important to compare the evidence against the theory to the evidence for it.

  Yes, that’s what I’m trying to do here. I feel this is a neglected take and on the margin more people should think about whether this theory is true, given the stakes.

  Presumably some of these people are hypochondriacs or have the flu? Also, I bet people with symptoms are more likely to use the app.

  With all due respect it’s not that hard to get data that you yourself find convincing, even if you’re a professor.

  “”Our first analysis showed we’re picking up roughly that one in 10 have the classical symptoms,” he said. “So of the 650,000, we would expect to see 65,000 cases.

  “Although you can have problems of self-selection and bias, when you’ve got big data like this you tend to trust it more. What we’re seeing is a lot of mild symptoms, so I think having this data should help people relax a bit more and stop seeing it as an all or nothing Black Death situation.

  “Other symptoms are cropping up. Thousands of people are coming forward to say they have loss of taste, and we may start to see clusters of symptoms.”″

  https://​​www.telegraph.co.uk/​​news/​​2020/​​03/​​25/​​monitoring-app-suggests-65-million-people-uk-may-already-have/​​

  They do meet more different populations of people though. So if a small number of cities have relatively widespread infection, people who visit many cities are unusually likely to get infected.

  You’d expect to see people to many severe cases amongst people who travelled for business a lot in January and February.

  Not likely. About 1% of Icelanders without symptoms test positive, and all the stats on which tested people are asymptomatic that I’ve seen (Iceland, Diamond Princess) give about ¹⁄₂ asymptomatic at time of testing (presumably many later get sick).

  I don’t quite understand what you’re saying here.

• Hauke Hillebrandt 28 Mar 2020 2:35 UTC

  3 points

  in reply to: ignoranceprior’s comment on: The case for C19 be­ing widespread

  No. My ambition here was a bit simpler. I have presented a rough qualitative argument here that infection is already widespread and only a toy model. There are some issues with this and I haven’t done formal modelling. For instance, this would be what would be called the “crude IFR” I think , but the time lag adjusted IFR (~30 days from infection to death) might increase the death toll.

  Currently, also every death in Italy where coronavirus is detected is recorded as a C19 death.

  FWIW, if UK death toll will surpass 10,000, then this wouldn’t fit very well with this hypothesis here.

• Hauke Hillebrandt 28 Mar 2020 2:39 UTC

  −1 points

  in reply to: Matthew Barnett’s comment on: The case for C19 be­ing widespread

  That’s true and that’s what they were criticized for.

  They argued that the current data we observe can be also be explained by low IFR and widespread infection. They called for widespread serological testing to see which hypothesis is correct.

  If in the next few weeks we see high percentage of people with antibodies then it’s true.

  In the meantime, I thought it might be interesting to see what other evidence there is for infection being widespread, which would suggest that IFR is low.

• Hauke Hillebrandt 28 Mar 2020 9:44 UTC

  4 points

  in reply to: CellBioGuy’s comment on: The case for C19 be­ing widespread

  By the end of its odyssey, a total of 712 of them tested positive, about a fifth.

  Perhaps other on the ship had already cleared the virus and were asymptomatic. PCR only works for a week. Also there might have been false negatives. I disagree that the age and comorbidity structure can only lead to skewed results by a factor of two or three, because this assumes that there are few asymptomatic infections (I’m arguing here that the age tables are wrong).

  In my post, I’ve argued why the data out of China might be wrong.

  Iceland’s data might be wrong because it is based on PCR not serology, which means that many people might have already cleared the infection, and it is also not random.

• Hauke Hillebrandt 28 Mar 2020 10:30 UTC

  1 point

  in reply to: Lukas_Gloor’s comment on: The case for C19 be­ing widespread

  I do not think that can be used as decisive evidence to falsify wide-spread.

  This is a non-random village in Italy, so of course, some villages in Italy will show very high mortality just by chance.

  That region of Italy has high smoking rates, very bad air pollution, and the highest age structure outside of Japan.

• Hauke Hillebrandt 28 Mar 2020 10:45 UTC

  1 point

  in reply to: DanielFilan’s comment on: The case for C19 be­ing widespread

  It looks more like you listed all the evidence you could find for the theory and didn’t do anything else.

  That was precisely my ambition here—as highlighted in the title (“The case for c19 being widespread”). I did not claim that this was an even-handed take. I wanted to consider the evidence for a theory that only very few smart people believe. I think such an exercise can often be useful.

  I don’t think this is actually how selection effects work.

  The professor acknowledges that there are problems with self-selection, but given that there are very specific symptoms (thousands of people with loss of smell), I don’t think that selection effects can describe all the the data. Then he just argues for the Central Limit Theorem.

  That the asymptomatic rate isn’t all that high, and in at least one population where everybody could get a test, you don’t see a big fraction of the population testing positive.

  There’s no random population wide testing antibody testing as of yet.

• Hauke Hillebrandt 28 Mar 2020 14:04 UTC

  3 points

  in reply to: Pablo’s comment on: The case for C19 be­ing widespread

  Cheers- corrected.

• Hauke Hillebrandt 28 Mar 2020 15:46 UTC

  −1 points

  in reply to: Pablo’s comment on: The case for C19 be­ing widespread

  Thanks Pablo for your comment and helping to clarify this point. I’m sorry if I was being unclear.

  I understand what you’re saying. However:

  • I realize that the Oxford study did not collect any new empirical data that in itself should cause us to update our views.

  • The authors make the assumption that the IFR is low and the virus is widespread and find that it fits the present data just as well as high IFR and low spread. But it does not mean that the model is merely theoretical: the authors do fit the data on the current epidemic.

  • This is not different from what the Imperial study does: the Imperial authors do not know the true IFR but just assuming a high one and see whether it fits the present data well.

  • But indeed, on a meta-level the Oxford study (not the modelling itself) is evidence in favor of low IFR. When experts believe something to be plausible then this too is evidence of a theory to be more likely to be true and we should update. An infinite number of models can explain any dataset and the authors only find these two plausible.

  • By coming out and suggesting that this is a plausible theory, especially by going to the media, the authors have gotten a lot of flag for this (“Irresponsible”—see twitter etc.). So they have indeed put their reputation on the line. This is despite the fact that the authors are prudent and saying that high IFR is also plausible and also fits the data.

• Hauke Hillebrandt 28 Mar 2020 16:09 UTC

  3 points

  in reply to: avturchin’s comment on: The case for C19 be­ing widespread

  Cruise Ship passenger are a non random sample with perhaps higher co-morbidities.

  The cruise ships analysed are non-random sample: “at least 25 other cruise ships have confirmed COVID-19 cases”

  Being on a cruise ship might increase your risk because of dose response https://​​twitter.com/​​robinhanson/​​status/​​1242655704663691264

  Onboard IFR. as 1.2% (0.38-2.7%) https://​​www.medrxiv.org/​​content/​​10.1101/​​2020.03.05.20031773v2

  Ioannidis: “A whole country is not a ship.”

• Hauke Hillebrandt 28 Mar 2020 16:15 UTC

  1 point

  in reply to: Matthew Barnett’s comment on: The case for C19 be­ing widespread

  Cheers—have taken this point out.

• Hauke Hillebrandt 28 Mar 2020 18:28 UTC

  4 points

  in reply to: jacob_cannell’s comment on: The case for C19 be­ing widespread

  Very good analysis.

  I also thought your recent blog was excellent and think you should make it a top level post:

  https://​​entersingularity.wordpress.com/​​2020/​​03/​​23/​​covid-19-vs-influenza/​​

• Hauke Hillebrandt 17 Apr 2020 10:12 UTC

  3 points

  on: April Coron­avirus Open Thread

  [Years of life lost due to C19]

  A recent meta-analysis looks at C-19-related mortality by age groups in Europe and finds the following age distribution:

  < 40: 0.1%

  40-69: 12.8%

  ≥ 70: 84.8%

  In this spreadsheet model I combine this data with Metaculus predictions to get at the years of life lost (YLLs) due to C19.

  I find C19 might cause 6m − 87m YYLs (highly dependending on # of deaths). For comparison, substance abuse causes 13m, diarrhea causes 85m YLLs.

  Countries often spend 1-3x GDP per capita to avert a DALY, and so the world might want to spend $2-8trn to avert C19 YYLs (could also be a rough proxy for the cost of C19).

  One of the many simplifying assumptions of this model is that excludes disability caused by C19 - which might be severe.