Last month’s Coronavirus Open Thread did a fantastic job at being a place for coronavirus-related information and questions that didn’t merit a top level post, but at almost 400 comments, many of which were great at the time but are now obsolete, it’s getting a little creaky. So for the next month (probably. Who knows what’s going to happen in that month) this is the new spot for comments and questions about coronavirus that don’t fit anywhere else and aren’t worth a top level post.
Wondering what happened in last month’s thread? Here are the timeless and not-yet-eclipsed-by-events highlights:
- Spiracular on why SARS-Cov-2 is unlikely to be lab-created.
- Two documents collating estimates of basic epidemiological parameters, in response to this thread
- Discussion on whether the tuberculosis vaccine provides protection against COVID-19.
- Suggestive evidence that COVID-19 removes sense of taste and smell.
- Could copper tape be net harmful?
Want to know what’s coming up in the future? Check out the Coronavirus Research Agenda and its related questions.
Wondering why the April thread is going up on 3/31? Because everything’s a little more confusing on 4/1 and I didn’t want the extra hassle.
In most major countries, daily case growth has switched from exponential to linear, an important first step towards the infection being under control. See https://ourworldindata.org/grapher/daily-covid-cases-3-day-average for more, you can change which countries are on the graph for more detail. The growth rate in the world as a whole has also turned linear, https://ourworldindata.org/grapher/daily-covid-cases-3-day-average?country=USA+CHN+KOR+ITA+ESP+DEU+GBR+IRN+OWID_WRL . Since this is growth per day, a horizontal line represents a linear growth rate.
If it was just one country, I would worry it was an artifact of reduced testing. Given almost every country at once, I say it's real.
The time course doesn't really match lockdowns, which were instituted at different times in different countries anyway. Sweden and Brazil, which are infamous for not taking any real coordinated efforts to stop the epidemic, are showing some of the same positive signs as everyone else - see https://ourworldindata.org/grapher/daily-covid-cases-3-day-average?country=BRA+SWE - though the graph is a little hard to interpret.
My guess is that this represents increased awareness of social distancing ... (read more)
I'd like to point out that the growth in India is still exponential (linear on the log-scale) https://www.worldometers.info/coronavirus/country/india/. This could be or become true of other developing countries.
India and other developing countries probably have a harder time controlling the outbreak (and governments and the young, food-insecure populations may judge the economic cost of social distancing to be higher than the risk of the virus).
There was a time when the number of worldwide cases appeared to stagnate because of the Chinese lockdown, but this number just hid the exponential growth of the European+US outbreaks.
What I said doesn't contradict any explicit statement in your comment, I just want to argue against the hypothetical deduction from "the growth rate of the world as a whole has also turned linear" to "and this means that the world is over the hill".
I would like this to be true, but two days on from the above comment, I am not seeing any linearity in the world growth rate (second link above), just three points in a nearly horizontal line a few days ago. The link for BRA+SWE shows the same thing for Brazil even more dramatically. New daily cases is a noisy enough measurement that I wouldn't entertain hope that we are past the exponential phase until seeing at least a week of a flat or declining rate.
The site I usually look for stats on is https://gisanddata.maps.arcgis.com/apps/opsdashboard/index.html#/bda7594740fd40299423467b48e9ecf6
The graph at the bottom right still looks like exponential runaway, even when you switch to daily instead of cumulative cases. And just like the above links, a few days ago there was a period of a few days of seeming flatness in new cases, but it didn't mean anything.
Edit: corrected corrupted URL to the arcgis.com site.
New post by Tomas Pueyo, the author of 'Coronavirus: The Hammer and the Dance':
'Coronavirus: Out of Many, One'... (read more)
[EDIT: Bucky points out that these cases make up too high a proportion of new cases for novel reinfection to be the primary mechanism, which means that there's negligible evidence to move the basic prior that general immunity should persist for a while (once the virus is well and truly defeated by the immune system).]
In South Korea, 2% of previously recovered patients have again tested positive and are again in isolation. There are several other explanations besides a general lack of acquired immunity (which would be the worst possible case, from a public health standpoint). But it seems critical that someone look at the evidence for the most dangerous possibility.
The magnitude of the numbers here seem wrong to represent people being infected twice.
From April 9-17 there were 74 newly discovered positive tests in those who had previously recovered. Over the same period there were only 203 new cases discovered. If the 74 received a new infection then they are getting infected at 2000x the rate of the general population.
Obviously there are a fair few reasons why they might be getting reinfected at a higher rate but I can’t think of a way it would be that much more. The reoccurrence of an existing infection would make a lot more sense.
There's a fascinating post by Patrick McKenzie (software engineer at Stripe, American living in Japan) on the Covid-19 situation in Japan.
With others, he did independent research into the issue when public sentiment stated the virus was well under control. They circulated this research privately and publically (anonymously), and the story even involves a cryptographic hash to pre-register their research (reasoning).
The whole post is interesting, and contains this gem that reminded me of LW concepts like a Crisis of Faith or Yudkowsky's Civilizational Inadequacy:... (read more)
I've seen an image on social media that suggests postural drainage, a physical therapy practice used mostly for cystic fibrosis, as a way to cope with COVID-19 at a sub-hospitalization stage; the shared image suggests that draining the mucus can keep a patient from needing a ventilator. (I'll transcribe the actual text attached to the image in a subthread, but it's of pretty low quality; I've written here what I think is the only interesting point.)
Unfortunately, Googling "postural drainage coronavirus" just gets me all the medical pages on postural drainage (because they now have headers about coronavirus).
It's a very cheap intervention for patients not on ventilators, the mechanism seems at least plausible, and it's the sort of thing that medical professionals might fail to consider. Is it worth taking a closer look?
This is the link I was looking for (but couldn't find!) for my previous answer:
Proning the non-intubated patient
Written by Josh Farkas assistant professor of Pulmonary and Critical Care Medicine at the University of Vermont.
Some general comments.
Images (figure 1) and information to see the effects of gravity and compression of the lungs here and here.
supine ~ "facing up"
prone ~ "facing down"
More info: prone-ventilation-for-adult-patients-with-acute-respiratory-distress-syndrome
Proning the non-intubated patient
So yes, definitely worth a closer look.
Thanks for the shout-out, but I don't think the thing I proposed there is quite the same as hammer and dance. I proposed lockdown, then gradual titration of lockdown level to build herd immunity. Pueyo and others are proposing lockdown, then stopping lockdown in favor of better strategies that prevent transmission. The hammer and dance idea is better, and if I had understood it at the time of writing I would have been in favor of that instead.
(there was an ICL paper that proposed the same thing I did, and I did brag about preempting them, which might be what you saw)
Some points from an interview with virologist Hendrik Streeck who is leading a systematic study in the German town of Gangelt in the county of Heinsberg, one of the epicenters of Corona in Germany (https://www.zeit.de/wissen/gesundheit/2020-04/hendrik-streeck-covid-19-heinsberg-symptome-infektionsschutz-massnahmen-studie/komplettansicht, ZEIT online, April 6, interviewed by Jakob Simmank and Florian Schumann):
... (read more)
- The team is testing, for the first time, a representative sample (1,000 from 500 households) for Germany on whether they are infected with Corona virus (smear test and antibody blood test).
- There was a famous carnival event in Heinsberg and in Germany it is kind of common knowledge by now that the large outbreak in Heinsberg can be traced back to that event. In the study, people were asked whether they attended that event, whether they had pre-existing conditions or take any medications; and all participants of that event were finally tested, and the researchers are reconstructing who sat next to whom and talked to whom. People had assumed that infection had spread via insufficiently clean draft-beer glasses; this seems to be wrong, most people had bottled beer. Moreover, peop
I've written a blog post on "Body Mass and Risk from COVID-19 and Influenza", available at https://radfordneal.wordpress.com/2020/04/06/body-mass-and-risk-from-covid-19-and-influenza/
Here's the intro:
Understanding the factors affecting whether someone infected with COVID-19 will become seriously ill is important for treatment of patients, for forecasting and planning, and — with factors that can be changed — for personal decisions aimed at reducing risk. Despite our current focus, influenza also remains a serious disease, so understanding its risk factors is also important.
Here, I’ll look at some of the evidence on how body mass — formalized as Body Mass Index (BMI, weight in kilograms divided by squared height in metres) — influences prognosis for respiratory diseases. Information specific to COVID-19 is still scant, but there is more data on influenza and on other respiratory infections (which includes coronaviruses other than COVID-19). Information on how BMI relates to general mortality should also be helpful.
Below, I’ll look at two relevant papers, plus a preliminary report on COVID-19. To preview my concl... (read more)
So it seems pretty likely cats are vulnerable to covid, and may be able to pass it to humans.
Could the coronavirus be interfering with the immune system in a way that is allowing Pneumocystis pneumonia to thrive?
My understanding is that Pneumocystis pneumonia, otherwise known as PJP or PCP, is caused by a fungus. It is highly opportunistic, and is rarely seen in people with healthy immune systems. It is highly associated with AIDS/HIV.
The fungus that causes it is widespread, and likely exists in the lungs of most healthy people.
I'm not sure about this one, but it seems relatively difficult to test for. Given it's rarity, it seems it is most are assumed to have it if they present symptoms and are positive for HIV/AIDS. If they are suspected, it seems they test for HIV/AIDS first.
Symptoms sound similar, if not the same as coronavirus
CT scans of those suffering from coronavirus and PJP are very similar, and both are very different from more typical pneumonia.
I have seen some papers that indicated the coronavirus may lower CD4 T-Cell counts, which is one of the reasons PJP is seen in HIV/AIDS patients. Not sure if this has been well studied and peer reviewed yet.
There exists a very effective treatment for PJ... (read more)
I emailed this comment and my reply to Elodie Ghedin, a molecular parasitologist and virologist at NYU for her thoughts on this. Here is her reply (posted with permission):
"Thanks for reaching out.
To my knowledge, there has not been an association of PCP with COVID-19. The percentages compared in that comment are not really comparing the same thing.
In severe COVID-19 cases there is indeed pneumonia but that's a general term indicating inflammation due to the virus itself. It can however be followed by an opportunistic infection, mostly from bacteria.
At first blush SARS-CoV-2 is not doing anything all that different to the immune system than any other acute virus infection. "
A smart friend pointed me to this study that explains that mediocre antivirals only work if administered right after infection. By the onset of symptoms the effect is already much reduced. (The study isn't clear as to what counts as "symptoms" except that they occurred 3 days before hospitalization, so maybe early warning signs like loss of smell don't count). HCQ is, at best, a mediocre antiviral.
This model agrees with a new study from China (N=150) that showed zero effect when giving patients HCQ 16-17 days after the onset of the disease. Of note, the study compared Standard of Care to SOC+HCQ, and I have no idea what the Chinese SOC is beyond the minimal requirement of intravenous fluids, oxygen, and monitoring that's mentioned in the paper. In particular, there's no info on whether it includes antibiotics like azithromycin, and whether it includes zinc. It's hypothesized that HCQ works partly by easing the entry of zinc into cells where it slows viral replication, and so they work well in conjunction.
https://www.medrxiv.org/content/10.1101/2020.04.10.2006... (read more)
Scott talked some days ago about how Brazil didn't take real coordinated efforts, and as a brazillian living in the country's largest city, I'm here to both defend my country and say that things are much worse than a lack of coordination.
The government, both at federal and state level, took quarantine measures earlier than other countries did (according to the Johns Hopkins institute), compared to number of confirmed cases. We officially closed schools at about 100~ confirmed cases, with parents refusing to take their kids to school much earlier. (Per comparison, Lombardy closed at about 200 cases or so).
They're also taking measures to have a semi-UBI going on so people have spending money for basics and utilities. Brazil also has much more robust work laws than US, thus people aren't at such a risk of sudden unemployment without social safety nets that can last them through this pandemic. They're also pushing for landlords and companies to open negotiations for rent and utilities.
The biggest factor here is the brazillian people, which are simply not caring about what the media has to tell them. Barely two weeks of quarantine in, and people a... (read more)
I've been playing with the Kinsa Health weathermap data to get a sense of how effective US lockdowns have been at reducing US fever. The main thing I am interested in is the question of whether lockdown has reduced coronavirus's r0 below 1 (stopping the spread) or not (reducing spread-rate but not stopping it). I've seen evidence that Spain's complete lockdown has not worked so my expectation is that this is probably the case here. Also, Kinsa's data has two important caveats:
... (read more)
- People who own smart thermometers are more likely to be health conscious which makes them more likely to be health conscious than the overall population. Kinsa may therefore overstate the effect of the lockdown by not effectively sampling the health apathetic people more likely to get the virus.
- Kinsa data cannot separate coronavirus fever symptoms with flu fever symptoms. At the early stages of coronavirus spread, seasonal flu illness dominates coronavirus illness and seasonal flu r0 is between 1-2. This means that a lockdown can easily eliminate symptoms caused by seasonal flu illness by reducing flu r0 below zero without reducing coronavirus's r0 below zero.
- I'm addressing
The Kinsa data is barely even weak evidence in favor of R0 < 1. The downward trend in fever readings are confounded, likely severely, by their thermometers having to be actively used vs. being a passive wearable. It seems plausible that more people will check their temperature when they are concerned about COVID-19, and since most people are healthy this will spuriously drive average fever readings down. Plausibly the timing of increased thermometer use will coincide somewhat with shelter-in-place orders since they correlate with severity & awareness of the local outbreak.
Their FAQ notes that they have seen 2-3x normal usage of their thermometers (this was as of March 29, they haven't updated this part of their FAQ since) and consider this "healthcare seeking behavior" a potential driver of their trends. This has not stopped them from promoting their data to government agencies and NYT, without mentioning this or any other limitations whatsoever (at least to the NYT).
I'm personally quite worried about disruptions to the food supply chain severe enough to cause food shortages in e.g. the Bay Area in the next few months but not sure what to do with that worry other than to stock up more on non-perishables. Would very much appreciate seeing more people thinking and researching about this.
Summarizing an article on gloves: https://www.n-tv.de/panorama/Einweghandschuhe-so-wichtig-wie-Masken-article21689035.html (April 2)
First, about virus survival on surfaces in general:
Germany's (kind of celebrity) virologist Christian Drosten's (Berliner Charité hospital) opinion on the study about survival rates of Sars-CoV-2 on surfaces and the possibility of smear infection:
He hypothesizes that for the experiment, dass für den Versuch Viruses in a larger drop were put on the surface, and even though in this way you can verify infecti... (read more)
The Imperial college model (yes, that one) has just been released, open-source, for anyone to look at. We don't actually know what the model's precise projections were (thanks to the UK governments lack of transparency), but we do know that ever since the UK's lockdown was declared the model had been predicting a peak on Easter weekend, which was, in fact, what happened in the UK. Imperial supposedly has the best infectious disease modellers in the world, and this is the code of the model that led the UK to dramatically reverse course, so its probably pretty accurate. Here's the GitHub.
I might later write a more indepth post, but for now the core idea. Controling a building to have between 50% and 60% humidity might reduce the amount of spread of corona. There are multiple studies that you can reduce the spread of infections in schools and hospitals that way.
There was also a paper out that suggested COVID-19 to spread less in climates with high moisture and temperature.
If anyone wants to collaborate with me on writing a post about this, please contact me.
For what it's worth, I upvoted your comment.
But since you stated that you had a source already, I don't see how it's asking much for you to post a link to the source you already said you had.
[EDIT: After a couple days, I regret the tone of my comments here. I don't want to discourage anybody from writing posts, or asking for help in composing posts. And I think "there oughta be a rule" was a poor summary of my position and sounded pretty hostile. I think it would be nice if people mentioning the existence of sources would link the sources they mention, and in general I'd like it if people linked source more often. But that wasn't really directed at you personally, it was spillover from elsewhere.]
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4420971/ is skeptical of cloth masks. Does anyone have any thoughts on it, or know any other studies investigating this question?
Should there be a non-coronavirus Open Thread?
Some potentially useful numbers I've been working on estimating:
1. The number of days lag between registered cases and deaths
2. The adjusted CFR for each country taking this into account
The method is essentially to try different lags (dividing current deaths by cases from x days ago) and see which length of lag gives a constant CFR over time (normally CFR increases with time as the growth rate of cases slows earlier than that of deaths).
Here are the results for a few countries:
China: 9 day lag, CFR=4%
USA: 7 day lag, CFR=6.5%
Italy: 4 day lag, CFR=14.5%... (read more)
Interesting COVID-19 vaccine development landscape publication in Nature.
Metaculus is running a competition for accurate, publicly-posted, well-reasoned predictions about how COVID-19 will hit El Paso, Texas, in order to help the city with its disaster response. The top prize is $1,000.
Dr. Birx said in the press conference today that the US is counting any patient who dies with COVID-19 as dying of COVID-19. Are deaths during pandemics normally counted this way? Is it legitimate to call this number inflation--i.e., is there something fishy going on here--or is this standard practice?
Cardboard and plastic: Tottori Prefecture goes low-tech to protect officials from COVID-19
This made my day.
I want Tottori spirit everywhere.
Is the Chinese coronavirus data fake?
If so, what's a good estimate of the actual number of Chinese cases & actual number of Chinese deaths?
Does anyone know why US cases and deaths tend to be lower on Sundays and (especially) Mondays, compared to other days of the week? Is it something with the timing of how the data are processed?
I put up some quick plots here:
Apologies if this has been explained before and I missed it.
What should be the relative importance of natural herd immunity vs vaccination, in anti-corona strategy?
Scott Atlas argues that mass isolation prolongs the problem by delaying natural herd immunity. Meanwhile, countries like Australia and New Zealand have engaged in national isolation as well, creating entire national populations where natural immunity will be rare.
Will we see the world divided between countries that rely on natural herd immunity, and those which rely on the artificial herd immunity of vaccination? Does it make sense to have a differenti... (read more)
I need your input on something. Sweden, as many of you know they are going for the herd immunity. Choosing to walk an unorthodox way.
They are still only reporting around ten thousand cases but with a death toll of 600 and rising. Probably the true number of infections is around 40k-100k depending on what mortality/asymptomatic cases we assume. The current rate, as in the number of hospitalizations per day is still within the the limits. It could probably go as high as double the death rate, before breaching the limit.
To reach heard immunity they need 60... (read more)
Video explaining the Czech Republic's experience of having everyone make home-made masks in about 10 days, from a starting point of almost no masks being worn in public in the country.
Here is their COVID19 infection curves on a log chart (seems to be flattening).
With noticeably different governance and social reactions in different locations, I wonder if this situation will spur migration in the coming few years. At what point is it worth moving to somewhere with more sane (still broken; nowhere is perfect) government and social behaviors, even if it's more distant from your personal networks?
Seattle and the Bay Area are looking pretty good compared to New York and Florida (this could reverse over the next few months, but it's unlikely that by end of year there'll be no difference in terms how we ... (read more)
Late Edit: Pangolins with this viral infection have been found from smuggled ones from both Guangxi and Guangdong provinces, but do not show up in wild pangolin populations in general.
Despite the virus being characterized in pangolins, after looking into this, I now think it is basically incorrect to think of this as primarily a "pangolin virus." The pangolins were a dying canary in a coal mine, and probably caught it from something else that serves as the real reservoir species for this nCOV precursor*.
These pangolins were being smuggled when they were ca... (read more)
I think the brief era of me looking at Kinsa weathermap data has ended for now. My best guess is that that covid spread among Kinsa users has been almost completely mitigated by the lockdown and current estimatess of r0 are being driven almost exclusively by other demographics. Otherwise, the data doesn't really line up:
... (read more)
- As of now, Kinsa reports 0% ill for the United States (this is likely just a matter of misleading rounding: New York county has 0.73% ill)
- New York's trend is a much more aggressive drop than what would be anticipated by Cuomo&apos
[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%
≥ 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-... (read more)
In addition to prediction markets, there are also, y'know, normal financial markets, which implicitly predict lots of things. But I don't personally know how to speak the language. For example, does the market say anything about the price of food, or possibility of shortages, in three months? Like, shouldn't there be some future / option / something whose price corresponds to a prediction about that? Or shortages of other things? Does anyone know?
A US study looking for recruits: NIH begins study to quantify undetected cases of coronavirus infection... (read more)
Why does recovery data seem so sparse? I only seem to be able to find that data for the global dashboards but that means it should be available. I would think that would be easily found as reporting only deaths is, to be nice, creating a situation where people will be misinformed and overly fearful.
I took a quick look on the links database but nothing jumping out for me there.
New data out of Germany using serological testing found 14 % of the population presented antigens against COVID19. This is massive if nearly 1/7 of the population has already contracted the disease and developed some type of immunity. This is only one piece of data, however, and is even much higher than the Iceland estimates of 50% asymptomatic and 50% symptomatic.
https://www.cnn.com/2020/04/01/europe/iceland-testing-... (read more)
I'm trying to make some educated guess about the situation, but it looks like the data are very lacking. Could someone validate my logic please?
1. Some people claim that SARS-CoV-19 could have been around for ages, "everybody's bad flu last autumn was this thing" and basically nothing is happening except panic. People are dying not because of the virus, but because everybody is going to hospitals making them overcrowded. People dying of other reasons just happen to also have almost-harmless COVID-19. When I've heard this couple wee... (read more)
IHME published a dashboard with state-by-state projections of coronavirus peaks: http://covid19.healthdata.org/projections
The accompanying FAQ is also interesting: http://www.healthdata.org/covid/faqs
Innoculate GI tract with live virus. Suffer GI symptoms. Get immunity. Avoid respiratory complications.
Exactly like variolation, except you do it intelligently to minimize lung infection.
SARS and SARS-Cov2 are both ACE2 dependent for cell entry.
ACE2 expression in AT2 cells in the lower respiratory track is known to be on the apical surface, that is the side of the cell facing airspace, not the basal surface facing vasculature. Hypothesis would be that lung infection is much more efficient and virulent by droplet delivery rather than by virus circulating in blood stream. I am also under the understanding that the kidney and heart complications are due to poor oxygenation due to the respiratory distress, not a primary viremia in those organs.
Tissue distribution of ACE2 protein, the functional receptor for SARS coronavirus. A first step in understanding SARS pathogenesis.
"In conclusion, ACE2 is abundantly present in humans in the epithelia of the lung and small intestine, which might provide possible routes of entry for the SARS-CoV. "
ACE2 expression by colonic epithelial cells is associated with viral infection, immunity and energy metabolism
The digestive system... (read more)
This article and the linked study propose that smokers are getting infected less often due to the nicotine rather than the smoking. Is it worth getting nicotine gum and patches?
Oxford COVID-19 vaccine begins human trial stage
I'm trying to formulate a response to, what at least in my circle of friends and acquaintances, is an increasing insistence that people had Covid-19 in November 2019.
If we assume someone did have Covid-19 in upstate NY for instance what else would have to be true?
I think mainly, that a novel virus made its way around the world without detection would be pretty major. And then it mutated in Wuhan, China unleashing this second, more virulent strain, meaning that the pattern of outbreak that we all witnessed beginning in Wuhan was some kind of 'sec... (read more)
TL;DR: No. The earliest I'd buy for pandemic-track COVID is early-to-mid December, and in China or maybe Australia. Otherwise, it'd have to be a non-pandemic substrain that died out early, and left no children behind except the first Wuhan strain. The theory loses in an Occam's Razor fight with "your friends probably had something else back then."
ETA: This post mentions a second independent line of evidence on the matter (using antibodies), and also dates the first COVID-19 cases to no earlier than December.
I'm going to be basing most of this on nextstrain's COVID-19 phylogeny data and their accompanying chart.*
The earliest sequenced US case we have came from Washington. The Washington strain's earliest sequenced sample was 5 weeks of mutation out from the Wuhan strain at the time, leading to the inference that it arrived (or at least split off from the Wuhan gene-pool) in about mid-January. Australia seems to have a divergent strain that might have broken off even earlier, possibly as far back as mid-December.
Going on their graph, they dated the Wuhan last common-ancestor (LCA) strain to roughly mid-December, and the all-strain LCA is the same one.
(I'm not going to detail all of h... (read more)
Ok, a question of which I assume that people here can quickly provide the answer:
How certain are we that age groups with low likelihood of developing symptoms - in particular, children - are actually infectious? Sure, there is asymptomatic spread in general, but I guess being asymptomatic also correlates with the ability to quickly kill the virus and thus not transfer it to others. So the first question is HOW infectious are people who are and stay asymptomatic? Is there good evidence on this?
Harvard published a study on link between PM2.5 pollution and mortality.
Places most hit so far are on the more polluted side so one can expect final CFR/IFR be lower than estimated from current data.
Mass testing seems like a promising brute force strategy that can keep R < 1 after lockdown, without requiring contact tracing. I'm pretty early in thinking about this but wanted to share my thoughts to encourage parallel efforts. A few possibilities (not mutually exclusive):
1) RNA testing: If everyone is given a daily RNA test and positives are isolated, transmission will likely be very close to 0. The US is still a factor of 1000 away from doing this (for comparison, RNA testing has scaled by 400x in the last month). However it seems likely that ... (read more)
How much do we know about gender differences?
I saw a reddit thread suggesting that women have different symptoms than men, though it was super anecdotal and I can't find it now. I know women have a lower death rate, and I understand that was originally suspected to be because men smoke more but more recently maybe that turns out not to explain the whole difference? This paper suggests that men have more ACE2 than women, which is the enzyme the virus binds to.
Is this a thread that's been well explored by others?
Something to keep an eye out for:... (read more)
"The Case for Universal Cloth Mask Adoption & Policies to Increase the Supply of Medical Masks for Health Workers"
Excerpt from Twitter thread summarizing it:... (read more)
Does anyone have any idea / info on what proportion of the infected cases are getting Covid19 inside hospitals? This seems to have been a real issue for previous coronavirus.
I'd say there might be a stark difference between countries / regions in this area. Italian health workers seem to have taken a heavy blow. Also, 79 deaths in Brazil (total: 200) came from only one Hospital chain/ health insurer, which focus on aging customers (so, yeah, maybe it's just selection bias?).
(Epistemic status: low, but I didin't find any research on that aft... (read more)
South Korea, as always, are a treasure trove on information - they publish details every day which includes major outbreak clusters, some of which are hospitals. Of the non-cult related cases where they have managed to identify the source of the infection, hospital based infections account for 20%. If you include cases where they haven't identified the source then it's more like 10% which is probably a fairer reflection as hospital clusters probably mainly do get identified.
(They changed their reporting layout on March 25th and the new version doesn't quite contain as much information so I've based this on the 24th)
Swiss cardiologist Nils Kucher is going to start a study to check whether blood thinners help covid-19 patients, suspecting that lung embolisms play a role in hospitalization and mortality. (https://www.n-tv.de/wissen/Helfen-Blutverduenner-bei-Corona-Infektion-article21722726.html)
I am not sure how it is possible that there are reports in the media claiming a low IFR (0.1%) when Lombardy has an official population fatality rate (i.e official COVID19 deaths over total population) of 0.12%, and unofficial one of 0.22% (measuring March and April all cause mortality there are ~10000 excess deaths) and a variability of up to 10x of casualties between towns more or less hit, indicating that only a small fraction (~10-20% imho) of the entire population was infected. I am pretty confident that the IFR is around 1% on average: it’s p... (read more)
Hi all. I haven't been to LessWrong in a while...but the mess in the world has reminded me how important it is for us to strive for clear thinking as a community. With that, I'd like to share a Coronavirus pandemic information site that has really good analysis for tracking the progress of the pandemic. It's here: https://ourworldindata.org/grapher/daily-covid-cases-3-day-average
(it seems that I cannot embed or add images)
<iframe src="https://ourworldindata.org/grapher/covid-confirmed-daily-cases-epidemiological-trajectory" style="width: 100%; height: 600px; border: 0px none;"></iframe>
How Large is the Iceberg? New Evidence from Kansas City
The details are currently vague, but I have tried to report key information, as this is one of the few efforts at random sampling that I am aware of. My main hope is to inspire someone with more expertise and ability to access details to expand the analysis.
Johnson County, with a population of 602k, has reported on preliminary results from an effort to test a representative sample of its residents. I have been unable to find details about how they constructed the sample, so cannot assess how re... (read more)
Why are surgical or self-made masks supposed to be better at protecting others than at protecting oneself? Naively, it seems to me that the percentage of filtered droplets/aerosol should be the same regardless of the direction in which it is breathed.
Idris Elba and his wife, two weeks after testing positive for the coronavirus, say they still have experienced no symptoms
The pool of people who 1. received a test while asymptomatic 2. tested positive and 3. are updating the public about their condition through mass media seems very small to me. The fact that two of them are turning out to remain fully asymptomatic seems to indicate that this is in fact likely to be a common thing. Somewhat surprising imo.
Seems like a good model for estimating total infections, from my quick look: https://observablehq.com/@danyx/estimating-sars-cov-2-infections
I haven't poked its methodology.
Which US federal agencies should receive more funding in response to coronavirus? Which should receive less?
From the Center for Health Security's covid19 brief:
More info here. Maybe someone was listening to Scott's surname-based lockdown suggestion.