[HN Gopher] Coronavirus clue? Most cases aboard U.S. aircraft ca...
___________________________________________________________________
Coronavirus clue? Most cases aboard U.S. aircraft carrier are
symptom-free
Author : mancerayder
Score : 73 points
Date : 2020-04-16 18:19 UTC (4 hours ago)
(HTM) web link (www.reuters.com)
(TXT) w3m dump (www.reuters.com)
| scythe wrote:
| Do we know if these cases are truly _asymptomatic_ or just
| _presymptomatic_ as was observed on the Diamond Princess?
|
| 48% asymptomatic initially:
| https://www.niid.go.jp/niid/en/2019-ncov-e/9407-covid-dp-fe-...
|
| 18% asymptomatic retrospectively:
| https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7078829/
|
| Also, 58% of asymptomatic COVID-19 infections still show damage
| to the lungs on CT: https://appliedradiology.com/articles/study-
| investigates-dia...
| blakesterz wrote:
| >> The majority of the positive cases so far are among sailors
| who are asymptomatic, officials say.
|
| I don't know much about this kind of thing, but isn't the most
| important word in that sentence "sailors"? I would think people
| living on an aircraft carrier are, on average, way different in
| many major ways than the average American. So it seems like
| making any kinds of assumptions based on this wouldn't be super
| reliable.
| richardw wrote:
| It probably means this is your best possible case outside of an
| Olympic village.
| edmundsauto wrote:
| If it's true that men are more susceptible to
| infection/complications/death, the only way the population
| could be better would be if the ship were staffed entirely by
| women. That would be an interesting scenario for military
| leadership to plan.
| londons_explore wrote:
| I'd take issue at the use of the word 'sailor', when it's been
| an awfully long time since the navy used sails to get into
| battle...
| delecti wrote:
| Sailor - noun: a person whose job it is to work as a member
| of the crew of a commercial or naval ship or boat, especially
| one who is below the rank of officer.
|
| Language evolves. Computers used to be people, my cellular
| telephone rarely conveys my voice, my laptop seldom touches
| my lap, I virtually never write anything at my desk.
|
| https://en.wikipedia.org/wiki/Computer_(job_description)
| https://en.wiktionary.org/wiki/telephone#Etymology
| https://en.wikipedia.org/wiki/Desk#Etymology
| Leary wrote:
| Sailors are very young. You can't assume that the proportion of
| people who are asymptomatic to be the same for every age group.
|
| The 60% asymptomatic percentage is also a lot lower than some of
| the assumptions flowing around the internet (~90%).
| m0zg wrote:
| Young people in the best shapes of their lives tolerate C19 well.
| I thought it was common knowledge.
| manifestsilence wrote:
| So people who are fit enough to pass active duty basic training
| tend not to have symptoms. Solution: put everyone through basic
| training?
| Loughla wrote:
| Solution: put everyone through basic training. Corequisite
| Solution: make everyone be 18-34 years old.
| sethammons wrote:
| The same for people who want to be taller: get them into the
| NBA as data shows basketball players tend to be tall.
| trhway wrote:
| >Solution: put everyone through basic training?
|
| i'm afraid the fatality rate caused by basic training, i.e.
| elderly and severe diabetes/hypertension/etc., may happen to be
| pretty close to the covid.
|
| Btw, i think the aircraft carrier commander is an outstanding
| and exceptional guy - he put the lives of his sailors above his
| career.
| eximius wrote:
| This is mixed news. While this indicates the death rate may be
| lower and the infection rate higher among the general population,
| the demographic of individuals in the US military are going to be
| of significantly higher health than the general population.
|
| So, it doesn't necessarily ease the risk for demographics already
| identified as 'at-risk'. If anything, their risk might be
| understated given the higher infection rate.
| DanBC wrote:
| I don't quite understand why "more infectious but less lethal"
| is better than "less infectious but more lethal" -- both mean
| that lots of people are going to die.
| mannykannot wrote:
| Even with the earlier estimates of how infectious it is, it
| seems quite likely that a large proportion of the population
| is likely to catch it sooner or later. If that is so, then
| the less lethal it is, the better.
| scarface74 wrote:
| Especially once you consider all of the pre-existing conditions
| that make you ineligible to be in the military.
| mc32 wrote:
| I think we should also consider that some members of the
| military depending on their duties get exposed to chemicals
| that the civilian pop don't get exposed to at the same
| levels.
| ashtonkem wrote:
| Or at all. Most of us will never come within contact with
| TNT during our life, while most military members will be
| exposed to its residue constantly.
| pvaldes wrote:
| Good point, yes, but I bet that Gulf war soldiers where also
| extra-healthy when they enlisted. Not so much when they
| returned home.
|
| Army, is an activity with lots of health risks, chemicals and
| strange diseases exposure attached. Not the best choice if
| you expect to live for one hundred years.
| lhuser123 wrote:
| That reminded me of an Army recruiter well known for his
| "tactics". People close describes him as a "Car salesman ".
| Apparently, is very good at making sure the candidate
| doesn't change his/her mind.
| gnopgnip wrote:
| There are a lot of people who have pre existing conditions
| and have no idea, even in the military. There was a marine
| recruit who died during basic training because of a heart
| defect, it wasn't an issue his whole life and it didn't come
| up as a problem during the in depth physical you get before
| hand.
| cryoshon wrote:
| this is a really good point. AFAIK, 100% of the canonical
| pre-existing conditions which are highly dangerous with COVID
| are disqualifiers for joining the military.
|
| this cohort will give us a much better picture of how the
| virus impacts a totally healthy and young population. as with
| countless other pieces of evidence, it should also help to
| put the "it's just a flu bro" falsehood to bed.
| perl4ever wrote:
| "AFAIK, 100% of the canonical pre-existing conditions which
| are highly dangerous with COVID are disqualifiers for
| joining the military."
|
| Including being "old".
| jjtheblunt wrote:
| Does the mortality rate across entire population (not
| particular subpopulations) exceed that of the flu?
| TheCoelacanth wrote:
| Almost certainly. The US had 27k deaths in the past two
| weeks. That's more than some entire years of flu related
| deaths. Give it another few weeks and it will be more
| than any recent year.
| ashtonkem wrote:
| Yes. Current understanding of the mortality rate is that
| it's roughly 10x more lethal than the flu across all age
| demographics. This means you might only have a 0.2% of
| dying as a 20 year old, but you only had a 0.02% chance
| of dying of the flu.
|
| The caveat is that mortality rate is intimately tied with
| the availability of certain types of care; if you need a
| vent and the hospital is full, you die even if otherwise
| you would've lived. Thus case mortality rate will change
| dramatically once the hospitals fill up.
| usaar333 wrote:
| I don't think that's true. covid has stronger age
| dependence. Just look at the ratio of covid vs. influenza
| deaths on the CDC's website
| (https://www.cdc.gov/nchs/nvss/vsrr/COVID19/index.htm).
| 3:1 covid:flu for over 85, but 1:1 for 25-35 and 1:10 for
| children. (relative ratios as we don't know total covid
| infections).
|
| This is especially striking with children: if the US had
| the same number of covid infections as seasonal flu,
| you'd probably have lower pediatric deaths from covid
| than flu.
| ashtonkem wrote:
| These statistics don't support that conclusion, because
| these statistics are for _total_ deaths. You can't
| meaningfully compare the total deaths from a disease
| that's done for the season (Flu) with one that's still on
| going (COVID-19).
|
| What you should be comparing is case fatality rates.
| usaar333 wrote:
| But can you not compare the ratios between age groups?
| That's all I'm doing here - showing deaths have a higher
| age correlation with covid than flu. - not making any
| statement about absolute CFR/IFR.
| ashtonkem wrote:
| No, because you don't know what the infection rate is by
| each demographic.
|
| You have to compare just the case fatality rate.
| Comparing fatality ratios alone is too likely to measure
| unrelated factors.
| usaar333 wrote:
| Fair enough, but would there be a reason it would be
| different? And even if it were, is that actually
| relevant?
|
| Anyway, here's some IFR estimations for covid by Imperial
| college: https://www.thelancet.com/journals/laninf/articl
| e/PIIS1473-3...
|
| You see significantly higher multipliers by age group
| than for flu. As one example, they are guessing teenagers
| have 1/17th the mortality rate of say a 40 year old. For
| flu (going by deaths), it's about 1/5th.
| gpm wrote:
| It's more likely that cases/infections is skewed by age,
| because we test severe cases more than mild cases, than
| infections as a whole is skewed by age. Assuming
| infections are uniformly distributed, or rather have a
| similar distribution to the flu, seems entirely
| reasonable until we have good data suggesting otherwise.
| manfredo wrote:
| Random testing in Germany has also revealed higher than
| expected rates of people with antibodies. Their IFR (infected
| fatality rate) was 2% overall based on non-random testing.
| Random testing has yielded an IFR or 0.37%.
|
| This does not increase the risk. These tests only test people
| who _had_ coronavirus. The larger this portion, the more herd
| immunity there is in the population. It implies that there
| _were_ a larger than expected number of people who had the
| virus, at some point in time. But that 's a lagging indicator.
| ashtonkem wrote:
| The former only holds if you assume that a large majority of
| asymptomatic carriers never develop symptoms. It's entirely
| likely that an asymptomatic positive test is a precursor to
| developing symptoms.
| xienze wrote:
| Sure, but remember that symptoms range from mild to moderate
| in the majority of cases.
| ashtonkem wrote:
| That's a different argument altogether.
| cm2187 wrote:
| It does, the more young healthy people are immune, the less
| likely the virus will make it to them.
| estebank wrote:
| Being asymptomatic is not the same as being immune. It means
| that more people will feel fine and spread the virus more
| because they don't know they have it.
| falcor84 wrote:
| Well, for what it's worth, if they get the virus while on a
| long tour of duty, by the time they get back they should be
| good to contribute to the herd immunity.
| kian wrote:
| Only if they form antibodies. Studies have been
| suggesting that people who get it in asymptomatic form
| are not all forming antibodies - leaving them wide open
| to be future communicators of the disease.
| koyote wrote:
| Wouldn't that mean that a vaccine is close to impossible?
|
| My layman understanding is that a vaccine relies on the
| body creating antibodies.
| [deleted]
| carey wrote:
| It's possible and desirable for a vaccine to stimulate
| antibody production where a "natural" infection would
| not, which is one of the things that will be tested
| during their development. An extreme example is infection
| with the tetanus-causing bacterium clostridium tetani,
| which doesn't provide natural immunity at all.
| eindiran wrote:
| Yes, a known failure mode of vaccines is if the person
| who is being vaccinated lacks the right B cells for
| creating antibodies matching the antigens on the surface
| of a pathogen. If the B cells a person has lack the right
| B Cell receptors, they can't generate the correct
| antibody response to an antigen, because they can't bind
| with/identify an antigen in the first place.
| Additionally, they may lack a sufficient number of
| antigen naive T cells, which haven't yet become
| differentiated as T memory cells and effector T cells.
|
| See below for more info:
|
| https://en.wikipedia.org/wiki/B_cell
|
| https://en.wikipedia.org/wiki/Memory_B_cell
|
| https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3760154/ -->
| this one is particularly good. A lot of good info in
| here.
|
| https://www.sciencedirect.com/science/article/pii/S026441
| 0X0...
|
| EDIT: this one covers the major routes of vaccination
| failure --> https://www.ncbi.nlm.nih.gov/pmc/articles/PMC
| 4962729/#!po=60...
| falcor84 wrote:
| That sounds really interesting, could you please link to
| more info about this?
| kian wrote:
| I'll check back in here later with links - didn't save it
| at the time I was reading through.
| eximius wrote:
| It's not clear to me that asymtomatic doesn't mean immune.
| If the primary symptoms are due to over-replication of the
| virus and not fighting it enough resulting in cell death in
| lungs and other airways, then asymptomatic infection
| indicates the immune system is fighting it enough to fend
| it off.
|
| Now, this rests on symptoms being directly caused by higher
| virus cell counts rather than toxic byproduct cascades of
| some sort. I'm not sure that's true
| three_seagrass wrote:
| This is devolving into semantics. Being a asymptomatic
| means you are infected, which means you are not immune.
| You can still develop symptoms later and/or still
| transmit the disease.
|
| You would be considered immune if your body produced
| antibodies that prevented infection. This immunity can be
| gained by successfully fighting the infection or by
| receiving a vaccination that triggers an immune response.
| jonny_eh wrote:
| But it would indicate the we may be closer to herd immunity
| than we thought, which would be great news.
| btilly wrote:
| This figure does not surprise me. It is in line with Iceland
| finding that 50% of people they tested were asymptomatic.
|
| However as https://www.propublica.org/article/what-we-need-to-
| understan... notes, in other samples about 75% of people who were
| asymptomatic at the time of the test went on to develop symptoms.
| So the fact that these sailors are currently asymptomatic does
| not mean that they will remain so.
|
| See https://www.cebm.net/covid-19/covid-19-what-proportion-
| are-a... for more on how different data points are all over the
| place.
| lbeltrame wrote:
| Are there any data on the _severity_ of the symptoms?
|
| From what I've gathered, but without any hard data, in non-
| severe cases (i.e. not needing hospitalization) they can vary
| from a slight sore throat, dry cough and mild fever, to the
| same with a high fever and general sense of exhaustion.
| Lewton wrote:
| bingo
|
| It seems like most everyone keep glossing over the fact that if
| you have a disease that doubles its infection count every x
| days, and it takes around x days to show symptoms you would
| always expect about 50% of infected to be asymptomatic at the
| time of testing
| ImaCake wrote:
| I feel that the asymptomatic thing is more wishful thinking
| in places where infection control has failed. Other countries
| have shown that you can contain the spread of Covid19, even
| if there are asymptomatic (or more realistic, low symptom
| severity) cases.
| bhouston wrote:
| We need widespread antigen testing in a place like Italy or
| NYC or Sweden. Would be so informative.
| standardUser wrote:
| Germany and Finland are doing this. Here are some results
| already completed in a German town showing that 14% of
| people tested positive for antibodies...
|
| https://spectator.us/covid-antibody-test-german-town-
| shows-1...
| three_seagrass wrote:
| That study did their research in a town that was already
| infected, meaning that our understanding of the infection
| rate for Covid-19 is probably lower than reality.
| azinman2 wrote:
| Some percent of confirmed recovered cases never develop
| antibodies it seems.
| JPKab wrote:
| Might also be important to note that sailors on an aircraft
| carrier are primarily college-aged.
| gopalv wrote:
| > 75% of people who were asymptomatic at the time of the test
| went on to develop symptoms. So the fact that these sailors are
| currently asymptomatic does not mean that they will remain so.
|
| There's also a wide range of symptoms from 102F fever all the
| way to sp02 dropping below 80, with varying impacts on the
| health-care infrastructure.
|
| At this point, conserving health infrastructure for normal
| incidence is as much of a problem (i.e even in the best case
| outcomes, there will be some cases of "stay at home, never
| catch the disease, but die from delayed response to a stroke").
|
| If the asymptomatic people get immune, then this might drop the
| other multiplier of the R0.
|
| Oof, optimism is hard to come by in these times.
| GANG718 wrote:
| This is because they're testing the entire population as opposed
| to simply those who end up hospitalized and those around them.
|
| We need population testing to get an actual idea of how many
| people in an area have it. There's likely way more cases
| nationwide than being reported. In NYC, most asymptomatic/low
| symptom cases of coronavirus aren't going to be tested until
| antibody testing later on.
| JoeAltmaier wrote:
| Yes. Many institutions test only if preparing to admit. Anybody
| else is told to go home and recover in isolation.
| glofish wrote:
| if the US has 33K deaths and the death rate is 0.6% then the
| US must have at least 5 million cases. If the death rate is
| lower (most likely around 0.3%) then it means 10 million
| infections.
|
| Also a good news actually.
| pesfandiar wrote:
| Those death rates in US are optimistic in my opinion. What
| if the actual rate is higher because of worse health in
| impoverished demographics, or the simple fact people might
| avoid healthcare because of its prohibitive costs?
| glofish wrote:
| these death rates come from published research if
| anything the death rates over across all age groups are
| even lower - this is a very common observation as
| initially most non-symptomatic are missed.
|
| there is a very strong age dependence with this disease,
| and probably many other risk factors - predisposition to
| pneumonia etc.
| pesfandiar wrote:
| If I understand correctly, research about the death rate
| is based on people who were tested positive (any source
| that's based on the general population?). This, depending
| on the region, could mean people with severe symptoms or
| non-randomly-selected test takers only. This adds much
| uncertainty to the estimated overall infection numbers.
| cm2187 wrote:
| Agree, though still a long way from herd immunity, which I
| understand starts at 50%-ish.
| btilly wrote:
| Herd immunity varies by disease. A lot.
|
| For each disease we estimate a number called R0, which is
| how many people the average person will transmit it to if
| no precautions are taken.
|
| Herd immunity sets in when only 1/R0 people have not
| managed to get it.
|
| With the flu, R0 is about 1.3. Meaning that herd immunity
| to a particular strain starts slowing the spread after
| about 1/4 of us are immune. (It can continue spreading
| for some time after that point.) I calculated that from
| the fact that 1 - 1/1.3 = 0.23076923076923076...
|
| R0 for COVID-19 is likely around 5.6 +- 0.9 per https://w
| ww.medrxiv.org/content/10.1101/2020.02.07.20021154v... we
| take the middle of that range, over 82% of us have to get
| it before herd immunity starts to work in our favor.
| dmoy wrote:
| This is also why people refusing the MMR vaccine is
| really, really hurtful to vulnerable populations. Measles
| R0 is like 15 or something - it's crazy infectious. So
| one kid in a daycare or class of 20 with parents who
| don't believe in vaccines is enough to push you under
| herd immunity. Bake in the fact that MMR vaccine is only
| ~97% good against measles, and you end up with a bunch of
| dead kids.
|
| We got lucky last time around in Seattle area, in that it
| only cost us $1m and 0 deaths to get it under control.
| icedchai wrote:
| Nothing new here. People were talking about asymptomatic spread
| by younger people for _months_. Why is Esper surprised?
| [deleted]
| andrewla wrote:
| There's always the chance that the test itself is not
| particularly good and just has a high false positive rate.
| Although it is difficult for a PCR test to produce a match if
| there is no genetic material present, it may amplify trace
| signals, depending on the cutoffs chosen.
| JackFr wrote:
| This seems to me the most obvious implication. That when you
| only test symptomatic people, the test might be accurate, but
| in testing everyone the false positive rate is much higher.
| ImaCake wrote:
| I looked into this a few weeks ago. The PCR test has an
| incredibly low false positive rate, below 1%. It is low enough
| that it is feasible to test a 100,000 people and expect
| basically zero false positives. The false negative rate is
| somewhere around 30%. So the real danger with PCR is that you
| will miss cases.
|
| The opposite is true for the antibody tests. The false negative
| rate is around 10% and the false positive rate is also around
| 10%. So in 100,000 tests, you would expect to miss about 1,000
| true positives. But, and this is critical, you would also
| mistakenly get 1,000 false positives - even if only 1/100,000
| people are actually infected!
|
| Next time you see someone claiming 50% asymptomatics. First
| thing to ask is whether they used PCR. Or if they used an assay
| with a terrible false positive rate.
| Mikeb85 wrote:
| All the data points to the fact that coronavirus is more
| widespread and less deadly than most outlets are reporting (after
| all, increase the denominator, the % goes down).
|
| The countries with the lowest death rates are also the countries
| that did the most comprehensive testing. Ditto for this aircraft
| carrier.
|
| Of course governments and outlets are fearmongering lest they be
| accused of not doing enough, but this thing is way overblown and
| I fear we'll be living with the consequences for an entire
| generation.
| Lewton wrote:
| No amount of lowering the IFR will change what has happened and
| is happening in New York, Italy and Spain
| [deleted]
| coherentpony wrote:
| Are you of the opinion that this is simply just a slightly
| worse flu?
|
| > All the data points to the fact that coronavirus is more
| widespread and less deadly than most outlets are reporting
|
| You couldn't be more wrong. There are nurses and doctors
| working on the front lines dealing with patients, and they're
| completely and utterly overloaded. Lack of resources. Lack of
| help from local and federal governments. They're the ones
| telling us this is way more deadly than it seems.
| Mikeb85 wrote:
| > Are you of the opinion that this is simply just a slightly
| worse flu?
|
| I mean I'm about 95% sure I already had it. Had literally
| every single symptom but the local health authority (Alberta,
| Canada) wouldn't test me. My SO had it worse but again, they
| wouldn't test her.
|
| Felt like a worse flu + more coughing and shortness of
| breath. Worse fever. My symptoms were bad for about 3 days,
| then felt like a cold for about a week, then a cough stuck
| around another week or two after. My SO had bad symptoms for
| about a week, was moderately sick for another week and a bit,
| but her symptoms disappeared pretty quickly afterwards. In
| either case, because we didn't require hospitalisation, AHS
| wouldn't test us.
|
| Anyhow, there's a massive body of evidence that there's many
| times more people infected than confirmed cases. Are you
| disputing that? Do you actually think there is no one
| infected other than confirmed cases?
|
| Our health authority, until a few days ago, wouldn't test
| anyone that wasn't a severe case or an at-risk group... You
| could literally have every single symptom and they'd simply
| tell you to stay home. Now they've only expanded testing
| because there's way less hospitalisations than their models
| predicted...
|
| Edit
|
| > There are nurses and doctors working on the front lines
| dealing with patients, and they're completely and utterly
| overloaded. Lack of resources. Lack of help from local and
| federal governments.
|
| Maybe that's a failing of your health care system? In Canada
| hospitalisation rates are way less than predicted. Our
| province also gave away a bunch of PPE because it doesn't
| appear as though they'll get used.
|
| Edit 2 - described more symptoms
| joshuahedlund wrote:
| With the orders of magnitudes involved here, it's possible
| for
|
| 1) many times more people infected than confirmed cases
|
| 2) many times more dangerous than the flu
|
| to both be true.
| wbronitsky wrote:
| This is the terrible take that will be everywhere in the
| next few weeks; "I think I had it, therefore I am an expert
| on the spread of this disease". There is no data or
| coherent argumentation here. I'm sorry you were sick, but
| this isn't an argument based on facts, it's an anecdote
| based off of little that might put people in danger.
|
| We need to inoculate ourselves from this argument because
| we are about to see it everywhere. Confirmation bias par
| exellence
| Mikeb85 wrote:
| Come on, all the data is out there. There's been 2
| million confirmed cases. Pretty much every expert agrees
| theres far more undiagnosed cases. We know the testing
| rates. We know who's being tested. The information is out
| there.
|
| Our local health authority is literally giving away
| PPE...
|
| Seems your only argument is that the idea it's not as
| dangerous as initially assumed "might put people in
| danger".
|
| Except the fallout definitely will. Shutting down the
| economy, limiting health care access has real
| consequences.
| wbronitsky wrote:
| I'm not asserting anything other than that you have no
| idea what you are talking about.
|
| The data aren't there, you aren't an expert, and you
| certainly aren't helping anyone. That's the most positive
| read I can give what I consider to be a reckless and vile
| take, and this take will be EVERYWHERE in the next few
| weeks. We need to guard ourselves because this take is
| deceptive; it lets us feel superior to everyone who is
| freaking out, which will help individuals calm down at
| the expense of public health.
| mns wrote:
| There are more hospitals and health workers doing nothing now
| globally (and no, I am not ignoring the outliers here, like
| Lombardy, Madrid, London, New York, I'm talking about the
| rest of the world), waiting for a wave that never came, even
| though everyone was 2 weeks behind Italy in the last 2
| months. Cancer patients, people with other serious issues are
| being ignored now, if one of your parents had a condition
| that is not being treated any more, you might see things
| differently.
| perl4ever wrote:
| People seem addicted to comparing numbers at a point in
| time and drawing conclusions, not considering whether they
| are changing at different rates, not to mention the
| derivative of the rate of change.
|
| Why would the ratio of, say, cases in NY vs Oklahoma vs.
| Japan stay constant? Just because? Clean living?
|
| I don't have expertise or authoritative predictions, I'm
| just saying that graphs are all over the place and
| practically everywhere has historical data with a different
| shape, and the end state/equilibrium is not know, except
| apparently, tentatively, for China and South Korea.
| mns wrote:
| Sad to see that everything that tries to bring some positivity
| to this crisis or a different point of view gets downvoted into
| oblivion here, including studies and opinions on how we're
| doing more harm with certain measures.
| Mikeb85 wrote:
| I get it. Everyone wants to find some meaning and importance
| to justify what's going on.
|
| Tons of jobs and wealth are being destroyed, governments are
| issuing tons of debt and expanding the money supply, people
| need to believe they're saving millions of lives.
| glofish wrote:
| I find this to be good even excellent news.
|
| It is quite possible the virus is not nearly as dangerous and
| lethal as people fear. If the young have nothing to worry about
| the prospects are pretty good.
|
| The best way to reach herd immunity is to have lots of immune
| people around you.
| kelnos wrote:
| The US military is not a representative sample of people; it's
| a bunch of people with better health and fitness than the
| general population. And the military is an institution that
| will reject people from joining based on a lot of the health
| conditions that make COVID-19 more dangerous to them.
|
| It's useful data, to be sure, but it also highlights that the
| disease can be really dangerous for people _outside_ certain
| groups.
|
| > _The best way to reach herd immunity is to have lots of
| immune people around you._
|
| It's not at all clear yet that recovering from COVID-19 confers
| any lasting immunity.
| Mikeb85 wrote:
| > It's not at all clear yet that recovering from COVID-19
| confers any lasting immunity.
|
| Coronaviruses aren't new...
| kelnos wrote:
| Not sure how that's relevant. Coronaviruses behave
| differently from each other, and it's not clear how _this
| one_ behaves wrt post-recovery immunity.
|
| And to your point, many forms of the "common cold" are
| caused by coronaviruses, and it's not like herd immunity is
| a thing there.
| Mikeb85 wrote:
| Short to medium term immunity is conferred to survivors
| of other coronaviruses. No reason to expect it won't be
| the same with this one.
| wbronitsky wrote:
| This reasoning seems like it needs data. Do we have any
| proof that Coronavirus immunity is similar across
| different viruses? Why should we expect that things that
| have the same name have the same immune response? This is
| a pretty cavalier take when lives are at stake.
| Mikeb85 wrote:
| Literally every health authority including the WHO is
| assuming immunity will be a thing...
| wbronitsky wrote:
| Please show me the data you have so we can have a shared
| understanding of the facts. Until then, there is no
| reason to continue this discussion; we don't come to HN
| to hear people's hunches
| inamberclad wrote:
| In the future, you might have a lot of immune people around
| you. Right now, however, it means you have a lot of invisibly
| _sick_ people around you.
| pvaldes wrote:
| > the virus is not nearly as dangerous and lethal as people
| fear
|
| Whereas being still deadlier than the combination of all
| wolves, dogs, crocodiles, hippos, lions, tigers, elephants,
| sharks, spiders and all known venomous snakes in the planet...
|
| Any serial killer wannabee would kill for having the same
| results in just three months
| glofish wrote:
| it is not such a great analogy though,
|
| considering that we have killed and exterminated most of the
| wolves, crocs, lions, hippos etc
| jbotz wrote:
| Since about a week ago data has been coming in from antibody
| testing in Europe... and the results are that IFR (infection
| fatality rate) is clearly less than 0.5% (0.37% in one city in
| germany[1]) and the number of actually infected people at least
| 15 times to 30 times higher than the confirmed number of cases.
|
| [1] https://www.n-tv.de/wissen/Heinsberg-Studie-entraetselt-
| Coro...
| joshuahedlund wrote:
| I'm not so sure that's clear yet. Just going on blunt
| metrics, the virus has already killed 0.1% of NYC's entire
| population, probably on pace to hit 0.2% if the down-curve
| even only roughly matches the up-curve. So it would have had
| to have spread to 50% of the population for the fatality rate
| there to be only 0.4%, which seems unlikely (there's only a
| smattering of antibody data around the world so far but
| nothing has found spread even close to 50%, especially at the
| level of a metropolis)
| MikeAmelung wrote:
| So with a 1% IFR, that would mean 20% infected. Would you
| agree with that number? Has anywhere else found 20%
| infected at the level of a metropolis?
| joshuahedlund wrote:
| I think 20% is definitely in the range of plausibility.
| See 15% infection rate in a set of tested pregnant women
| in NYC[1]
|
| I think the preponderance of evidence currently points to
| an IFR of 1% or maybe a bit lower.
|
| [1]https://www.nejm.org/doi/full/10.1056/NEJMc2009316
| MikeAmelung wrote:
| Yes, very interesting, NYC will certainly be an important
| source of data for the foreseeable future.
| glofish wrote:
| This is massively informative. If anything pregnant women
| take a lot more precautions than other people. They are
| most likely under representing the overall infection
| rate.
| [deleted]
| claytongulick wrote:
| When you include 3,700 non-positive deaths in your total
| death count, yeah - the numbers look scary.
|
| The reporting we're seeing is CFR, __not __mortality rate.
| They are very different things.
|
| Mortality rate is the number of deaths caused by a disease.
|
| CFR (Case Fatality Rate) is the total number of deaths by
| those diagnosed with a disease.
|
| They are very different numbers, and have very different
| meaning for different analysis and methodologies.
|
| Saying that that virus has killed .1% of NYC's population
| is inaccurate.
| joshuahedlund wrote:
| Even w/o those non-positives, the death count for NYC is
| in the neighborhood of 8,000[0] (and still rising at a
| decent clip) for a population of 8 million. That's 0.1%.
|
| You can also look at individual counties[1] and you get
| some variation but the same picture. Ex. 2.7k deaths in
| Queens for a population of 2.3mil, 0.4k deaths in
| Richmond for a population of 0.4mil
|
| (That's 0.1% for the entire population and not even
| nearing the maximum yet, so obviously the IFR's and CFR's
| will be even higher.)
|
| [0]https://www1.nyc.gov/assets/doh/downloads/pdf/imm/covi
| d-19-d...
| [1]https://covid19tracker.health.ny.gov/views/NYS-
| COVID19-Track...
| glofish wrote:
| also while this may sound insensitive 0.1% of the
| population is not the same as X percent of old and sick
| people
|
| it is not like the virus takes down everyone equally. The
| overwhelming majority of those affected are both old and
| fairly sick already.
|
| Again I am not implying anything other than there is
| clear skew and the measures should target those that are
| at risk. It makes no sense to create generic, unworkable
| rules where we lock up all 20 year olds that have no risk
| whatsoever. It is not realistic.
| chefkoch wrote:
| That study has been widely critized as there a many false
| positives with this kind of test and the counting method
| seems flawed.
| yread wrote:
| As another data point in the Netherlands (officially 30k
| cases - only serious cases and hospital workers were tested,
| 30% of the tests are positives), actual seroprevalence is 3%
| ~500k people have been infected (~2 weeks ago), dividing the
| excess deaths, you get 1.3% mortality rate.
|
| https://twitter.com/jankluytmans/status/1250769486174654464
| endymi0n wrote:
| Note though that the study, its methods and especially its
| politically charged presentation by repeat social media
| offenders are still disputed [1]
|
| [1] https://www1.wdr.de/nachrichten/offene-fragen-heinsberg-
| stud...
| Barrin92 wrote:
| Today there's been a new result from antibody tests in the
| netherlands done on blood dononrs which showed about 3%
| infection rate. Extrapolated to the population that would
| imply 500k infections, 20x higher than the official stats.
|
| The Heinsberg study isn't the only source pointing to this.
| Almost a month ago the NYT also ran a story on randomly
| tested Iranian airplane passengers which suggested that as
| of that time there may already have been 500k-5mil
| infections in the country.
|
| https://www.straitstimes.com/world/europe/dutch-study-
| sugges...
| Lewton wrote:
| Netherlands is currently at 30000 cases with 3000 dead,
| cfr of 10%. 20x infection would put the IFR at 0.5% which
| is well in line with what is expected
| perl4ever wrote:
| Possibly dumb question, how do we know someone with
| antibodies was exposed? The whole idea of vaccination is
| based on multiple things producing the same antibodies,
| so isn't it plausible there could be related viruses or
| genetic factors or something that would lead to
| antibodies for some people that hadn't been exposed?
| koyote wrote:
| > If the young have nothing to worry about the prospects are
| pretty good.
|
| Italy posts a weekly pdf analysing the demographics of their
| deceased:
| https://www.epicentro.iss.it/en/coronavirus/bollettino/Repor...
|
| Not a single death of anyone between 10-19 and only one death
| under 10. 7 in their 20s. Those are statistically minuscule
| numbers considering Italy has over 22k deaths and over 168k
| confirmed positives.
|
| This paragraph is also quite interesting:
|
| "As of April 13th, 217 out of the 18,641 (1.2%) positive SARS-
| CoV-2 patients under the age of 50 died. In particular, 47 of
| these were less than 40 years (32 men and 15 women), age range
| between 5 and 39 years. For 6 patients under the age of 40
| years no clinical information is available; the remaining 33
| had serious pre-existing pathologies (cardiovascular, renal,
| psychiatric pathologies, diabetes, obesity) and 8 had no major
| pathologies."
| hnCensorFreedum wrote:
| When we find out obese, smokers, asthma, were considering
| themselves "healthy" and not "at risk", it will explain a lot.
|
| Until then it seems day drinking has gone up, suicide, and home
| abuse has gone up.
|
| All because there's a 20% increased survival if you can be put
| on a ventilator. Flattening the curve may have some unintended
| consequences.
|
| My kid couldn't get his surgery in all of this..
| paypalcust83 wrote:
| There are multiple, dynamic risk-factors being discovered,
| treatment options, and different genomes of this species of virus
| circulating.
|
| 1) Being overweight is a major risk-factor for requiring critical
| care, and most US military folks aren't weight-enabled.
|
| 2) Being older is another risk factor. Also, most US military
| folks aren't well-aged either, typically in their 20's-30's.
|
| 3) Having type A blood group is a _potential_ risk factor. Type O
| blood group is a _potential_ protection factor.
|
| 4) Being male was a risk-factor for the L-strain. It's possible
| the military folks caught an S-strain that has less gender
| specificity, but it also may have nothing to do with it.
|
| 5) SARS-CoV-2 as a species maybe drifting genetically towards
| more communicability but less virulence. H1N1, HIV and others
| have also shown this pattern.
|
| 6) COVID-19 may not be best helped with non/invasive high-
| pressure ventilation that causes extreme barotrauma. In fact, it
| may not even be the same as previous instances of ARDS.
|
| 7) It's possible they were exposed to a variant of one of the
| newer genomes of S-strain that goes up to 78% "asymptomatic"
| community spread.
|
| 8) "Asymptomatic" means subclinical in terms of manifested,
| obvious symptoms. There is still the real possibility of internal
| organ damage regardless. Only a vaccine will be able to end this
| threat.
| empath75 wrote:
| > 5) SARS-CoV-2 as a species maybe drifting genetically towards
| more communicability but less virulence. H1N1, HIV and others
| have also shown this pattern.
|
| This is not true for either of those diseases.
| ivoras wrote:
| Adding to that, Netherlands' study of antibodies in blood donors'
| samples shows about 10x difference between the number of reported
| / tested cases and actual cases in the general population (i.e. a
| lot more people got it and were not sick):
|
| https://www.nytimes.com/reuters/2020/04/16/world/europe/16re...?
| feral wrote:
| The Netherlands has 3.3k deaths vs 29k confirmed cases, which
| would give a CFR of ~10%
|
| I.e. the Netherlands aren't testing much.
|
| A 10x reduction there brings it back to the CFR range we see in
| countries with bigger testing programs.
|
| I'm not a specialist but have been following this for a while,
| and have yet to see evidence the IFR for this isnt around
| 0.5-1% (assuming decent healthcare).
|
| That's what we saw in the Diamond Princess data, and a bunch of
| other places.
| Gibbon1 wrote:
| My current bet is younger healthy people are more likely to
| be asymptomatic. And older people much less so. Theodore
| Roosevelt with likely a young population, most are
| asymptomatic. Diamond Princess much older population most are
| symptomatic.
| alexbanks wrote:
| This is a thing I've been thinking about a lot. We're quick
| to say "We're not testing enough", but also quick to throw
| statistics around "disproving" the amount of asymptomatic
| cases. I am on the side of "It's probably orders of
| magnitude widespread than most countries think", and the
| number of totally asymptomatic cases is actually far far
| higher. You can't test only the old and the already sick
| and then accurately assess likelihood to develop symptoms.
| Your sample is totally wrong.
| mrfusion wrote:
| Could past infections from other corona viruses be Protecting
| people? I'd like to see research on that.
| alkonaut wrote:
| Were they testing for the virus or for antibodies? If it was
| testing for the virus tests only show positive for a few days
| then testing everyone on board will miss those who already had
| it, correct?
| greedo wrote:
| According to the Captain's email, sailors were tested, and
| results known the next day. I don't know what equipment they
| had onboard the Roosevelt, but the quick turnaround might
| indicate the type of test. These tests were also performed
| around Mar29.
| alkonaut wrote:
| Sounds like RT-PCR tests. Serological tests probably aren't
| available in that scale yet (unsure).
|
| Regardless, it's going to be extremely interesting now that
| countries start doing random serological tests.
|
| I read today about a group of Swedish athletes who visited a
| competition in Wuhan in October and some developed severe
| respiratory issues afterwards that couldn't be diagnosed.
|
| Edit: 5 were tested and 1 was positive which was interpreted
| as being a later infection. So no October infection.
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