Show HN: Lanes – a minimalist week-planner and Pomodoro timer - <AUTHOR> https://lanes.io <comment><USER2> Would be good to start off your landing page with a headline and some copy explaining your product. I didn't quite get it at first.

You need something like...

        Lanes is a simple to-do list with a built in pomodoro tracker designed
        to help you stay focused during your day.

        -- Insert screenshot of Lanes in action --

        Here's how it works:

        1. Build your to-do list for each day

        2. When you're ready to work, start a pomodoro tracker.
           The top task for the day is what you should be working on.

        3. Once your pomodoro is up... stand up, stretch, and if you've completed
           your task, mark it as done.

        4. After your short pomodoro break, goto 2.

        -- Insert testimonials about how lanes helped your customers save X
           amount of time or get N things done or achieve 100% increase
           in tasks completed --

        What are you waiting for... you should sign up
        for Lanes and start getting things done!"

<comment><USER3> Basically what you have in the 'what is lanes' page, make that your home page. Why hide it and risk people leaving because they don't know what it is.

<comment><USER4> The issue is, I went to the "What is Lanes" page, clicked on each of the features to see a description and got...nothing of value. The feature became bolded and crossed-out, and that's it. No video loaded, no text appeared.

</comment></comment></comment><comment><AUTHOR> Hey HN. This is the latest version of a task management app I've been building since mid-last year. Since then I've turned about 100 pieces of feedback* into incremental improvements/changes.

Still much to do so before I dig into the next set of updates I figured I'd share here and get your take. Cheers.

*A good chunk of which were around improving drag and drop, which turned out to be easier said than done.

<comment><AUTHOR> Update: I'm actually wowed this post got any traction, let alone time on the front page as I'm sure many people here could make a task manager in their sleep. Thanks, HN.

That said, the hard part isn't the tech, it's making something people want to use and use again. That's key. So excuse the app being rough around the edges - it will be refined - and thanks for the advice.

</comment></comment><comment><USER5> I think I might know what this is attempting to do, but can't actually tell for sure.

I briefly saw some "action" links or nav menu in the top-right (day, week, poms), but then the "what is lanes" green bar at the top covers up the action menu. The "what is lanes" thing didn't explain anything to me. And when I forcibly deleted the bar using web inspector, then the action buttons didn't work (day / week / poms). Very confusing. (But a big fan of pomodoro technique so looking forward to seeing what exactly it is you've created once it gets explained better and the UI gets cleaned up.)

<comment><AUTHOR> All solid points. The 'what is Lanes' tutorial is being improved right now, as a little too sparse on the detail.

Thanks for the comment.

<comment><USER4> Sparse implies that there is something there. When I click on any of the features to get an explanation, it just becomes bold and gets a strikethrough. After I click on all three, a button shows up saying "Start Accomplishing". That's not much in the way of a tutorial. I apologize for sounding harsh, but I don't really want to learn how to use your product by trial and error or without at least some idea of what it will look like when I am using it.

<comment><AUTHOR> Not harsh at all. Each clicked link should result in a gif showing the feature in action. If that's not showing at all then looks like I've a browser incompatibility to fix.

</comment></comment></comment></comment><comment><USER6> I would love to see some solution that integrates time blocking and pomodoro.

After trying various todo lists and kanban boards I finally settled on using my google calendar which works perfectly as both my todo list and scheduler.

More on this [http://calnewport.com/blog/2007/12/03/monday-master-class- do...](http://calnewport.com/blog/2007/12/03/monday-master-class-dont-plan- your-day-with-a-to-do-list/)

</comment><comment><USER7> Mozilla/5.0 (Macintosh; Intel Mac OS X 10_11_3) AppleWebKit/601.4.4 (KHTML, like Gecko) Version/9.0.3 Safari/601.4.4

Clicking the 'what is lanes' thing, I get this:

        [Warning] [Vue warn]: Unknown custom element: <v_settings> - did you register the component correctly? (bundle.js, line 13)
        [Warning] [Vue warn]: Unknown custom element: <v_connect> - did you register the component correctly? (bundle.js, line 13)
        [Warning] [Vue warn]: Unknown custom element: <v_bgt> - did you register the component correctly? (bundle.js, line 13)
        [Warning] [Vue warn]: Unknown custom element: <v_imagegal> - did you register the component correctly? (bundle.js, line 13)
        [Warning] [Vue warn]: Unknown custom element: <bgtab> - did you register the component correctly? (bundle.js, line 13)

Works fine in Chrome.

</comment><comment><USER8> Not sure if you know this but after you go through the process to create a task and you don't seem to have a way to edit it.

You also may need to streamline your sign up screen as it defaults to login without clear messaging.

Seems like a good start but you may have to work on your actual use cases and step through it with a few brand new users.

</comment><comment><USER9> This looks pretty nice, a bit ago my preferred planner/pomodoro app broke so I might use this.

A caveat would be having the top right menu be a bit more distinguishable, it can get lost very easily with some backgrounds:

[http://puu.sh/n19Fx/b34d4c217f.jpg](http://puu.sh/n19Fx/b34d4c217f.jpg) (With POM :Hovered)

However, this can be fixed using your favorite CSS injector so it isn't that problematic. I just added:

      .view_item {
        color: white;
      }

      .view_item_active {
        color: #191919;
      }

I have a concern, how do you plan to monetize?

<comment><AUTHOR> Looks good, will make the menu more distinguishable in the next release.

Monetizing: focus is on creating a great user experience now. Once that's achieved and the app adds value there's a few ideas

</comment></comment><comment><USER10> Also, did you want us to login / create an account? I show up and get a timer, but couldn't really tell what was supposed to happen other than immediately signing up for an account.

<comment><AUTHOR> Yeah, that's the idea. I think the consensus is better onboarding so will improve it.

</comment></comment><comment><USER11> Looks interesting, great work!

Suggestion: If you allow custom background, think carefully about the font colors. On the default background (tree & blue/gray sky) it was very hard to notice "up next" and "later" lablels - I wouldn't notice them were it not for your intro video in which they were more visible).

Also, a simple way to get back to "today" in the week view. I was surprised to find out it wasn't in the leftmost page.

<comment><AUTHOR> Thanks, Senko.

The custom list section is going to be improved in the next update. Right now it's two uneditable labels which is kinda weak. A more visible, more customizable version coming soon.

Will look at a 'jump to today' option too.

</comment></comment><comment><USER12> When I saw the title I expected an application, i.e. something I could run offline. What are the benefits of using an online website? Why would I use this website instead of my offline pomodoro timer?

<comment><USER13> I was hoping for offline too. The trouble with online is I spend >50% of my waking hours with no signal or when I do have signal I don't have data. Even at home signal is intermittent at best. e.g. I pick up the phone to answer a call and phone loses signal between table and ear.

Current apps always seem to be built in the expectation of perfect always on data and cope terribly (if at all) with intermittent or poor conditions. It's frustrating to say the least

</comment></comment><comment><USER14> I love the weekly planner idea. Of all the to-do lists I've looked at, none of them seem to support that critical feature.

Are there any other weekly planner apps like this?

<comment><USER15> I used this one for a while:

[https://teuxdeux.com/](https://teuxdeux.com/)

</comment></comment><comment><USER16> I signed up but this is really something I will never use again. I like the idea of a week-planner but this doesn't click with me at all.

</comment><comment><USER17> Awesome concept, I want something exactly like this. As others have said, improve your onboarding!

</comment><comment><USER18> A landing page that doesn't peg CPU via javascript loops on the opening page would be nice.</comment>


Banknotes for a Japanese-occupied Hawaii - <AUTHOR> http://www.atlasobscura.com/articles/object-of-intrigue-banknotes-for-a-japanese-occupied-hawaii <comment><USER2> Considering the problems people occasionally have spending $2 bills, I could only imagine the reaction you'd get trying to use one of these.

<comment><USER3> People deface bills all the time with more egregious doodles.

The "HAWAII" on the front appears subtle[1].

[1] [http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m5...](http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2050601.m570.l1313.TR12.TRC2.A0.H0.Xhawaii+dollars.TRS0&_nkw=hawaii+dollars&_sacat=0)</comment></comment>


The Strong National Museum of Play - <AUTHOR> https://www.youtube.com/watch?v=6HZLNNOFkMY <comment><USER2> I've been there a bunch of times but I never knew how extensive their stash was because it's been generally the same stuff on display for the past 10 years. I'm guessing it's not easy to get in on a behind the scenes tour.</comment>


Show HN: I published my first website – ShellMagic.xyz - <AUTHOR> https://shellmagic.xyz <comment><USER3> Some feedback you probably won't hear from the HN crowd:

Give more context to the site for initial visitors. Its going to be more obvious to those who visited from HN but not to those who stumbled upon it somehow. A little blurb at the top saying this is a reference site for bash scripting syntax and maybe why you saw the need for such a thing would do ease people into the site a bit.

I hate the popup at the bottom, I will hesitate to use the site again because of that (just like many of us avoid news sites with pesky popups), Its a major turn-off. Probably an unpopular opinion around here, but just maybe make a note at the bottom regarding the privacy stuff unless there are legal reasons not to (I'm not up on all the regulations) If you can't avoid it, make it way less intrusive.

Overall its really nice and I love to see better documentation made around old-school linux/bash tools and syntax as I often feel the documentation can be unwieldy with a lot of knowledge assumed. +1 to examples as others have said. Keep it up! :)

<comment><USER4> It would definitely be helpful to have more context. I know some bash, but I'm far from an expert. The first thing I see on the page is a list of flags, but no clue what commands these flags are used with. A few usage examples would help a lot.

For example "-e checks if files exists" How? -e _filename_ ? This doesn't work?

<comment><USER5> If you're just wondering, try:

      test -e file

or:

      if [ -e file ]; then
          echo "File exists!"
      else
          echo "File does not exist!"
      fi

Edit: Untested, I'm currently not at my desk to verify it :)

</comment></comment></comment><comment><USER6> Kudos!

As a nostalgic side note, I'm not even that old, and I miss when the Internet looked like this. Just regular folks learning HTML and writing about something they find interesting. These days, everything looks like it was built in a Wix or Squarespace factory.

<comment><AUTHOR> Thank you - appreciated =)

</comment></comment><comment><USER7> > Access Codes & Permissions

This section is missing stuff like setuid, sticky bit, extended attributes, etc. (SELinux stuff and setgid? I'm not sure if there's more.) For example, `ls -ld /tmp` shows `drwxrwxrwt`, `ls -l /bin/sudo` shows `-rwsr-xr-x`.

> History Expansion

To this section, it might be good to add `!$`. Also maybe a quick overview on word designators, to cover syntax like `!:^`, `!:2`, `!:<asterisk>`, etc. There's also modifiers, like `!$:h` to return the (h)ead of a path that's the last argument of the previous command, etc.

> Bash Globbing

> @ Matches exactly one of a given pattern

It might be better to put these extended glob ones as @(pattern-list) for example, just like it is on the manpage. Putting it just like @ next to ? or <asterisk>, implies that it just goes like that alone.

> Overview of Bash Symbols

> $(( )) is used for saving the output of arithmetic.

I guess you could save it, but you can also pass it directly to where you need it. I wouldn't call `echo $(( 1 + 2 ))` saving it.

> $[] deprecated integer expansion construct which is replaced by (( ))

No, it's replaced by `$(())`.

EDIT: Removed the part about the file types. You have that covered. However, you wrote

> c Special file

> b Block device

They're both special files. `c` is for character devices.

<comment><AUTHOR> That's a great help! Thank you.

</comment></comment><comment><USER8> Very cool, thanks for sharing. Here's some trivial suggestions.

\- There's a lot of info here, so I think you should aim for curation and conciseness, rather than completeness. For example, in File Test Operators, your first two entries (effectively, the first two entries a visitor sees) is `-e` and `-a`, both of which you describe as "File exists", though for the latter, you write: "(identical to -e but is deprecated and outdated)". Is there any reason for `-a` to be included if it's not useful? When I use a cheatsheet, I just want what's most useful, not a full historical reference.

\- This is a minor thing, and very much imho, but it was a little distracting to see Times New Roman (or rather, the Mac default serif font) as the base font for the descriptive text, which is a font that I associate with an unstyled (i.e. unpolished) website. IMHO , it looks a bit better in Georgia, or a sans-serif like "Helvetica Neue". Again, just imho, I'm sure others might vehemently disagree.

\- The associated twitter handle looks like @shellmagic1 – why not use the handle @shellmagicxyz, which is currently unused?

<comment><AUTHOR> \- I'll be making a section for deprecated stuff and move everything of that sort into one section. Good suggestion.

\- I've added a bunch of new fonts to the site, just now. It's a temporary selection of fonts - but include nicer ones like Source Code Pro for code, and a sans-serif for headings and navigation bar.

\- Thank you very much for mentioning that. That's a way nicer handle!

</comment></comment><comment><USER9> I always find the context switch to get to a website jarring, and really really love tools that give me documentation on the command line. For example, I can type "go doc foo.Bar" and instantly read the docs for foo.Bar (where foo is usually resolved to example.com/some/go/package/foo, based on what is in go.mod and installed on the system). So for this, I would really like bash's built-in help to show me all this stuff.

They did a 10% implementation of what would be good:

        $ help [
         [: [ arg... ]
             Evaluate conditional expression.

             This is a synonym for the "test" builtin, but the last argument must
             be a literal `]', to match the opening `['.

But it doesn't know how to dive into [ and show docs for the operators, i.e., "help [ -e" doesn't work. The [ documentation also doesn't tell you what options are available, and of course [ doesn't implement --help (but, of course, /bin/[ does. And people say computers are hard to use! Psh!).

So anyway, if this could all be fixed with a command-line utility, that would be wonderful. It is likely that if I ever need to remember what [ -e does, I'll "man [" or failing that "info bash" or failing that, give up and write the program in go so at least I can work from some documentation.

<comment><USER10> > It is likely that if I ever need to remember what [ -e does

I realize a lot of folks consider the context switch to paper to also be jarring, but this is why I like analog reference works. I remember roughly how far in to the book the table of all those obscure flags are, and the book more or less falls open to it, because I've been there before.

</comment></comment><comment><USER11> Nicely organized and well done! Thank you.

For all people like me addicted to this kind of reference websites full of information, check out [http://hyperpolyglot.org/unix- shells](http://hyperpolyglot.org/unix-shells) (and all pages on [http://hyperpolyglot.org/](http://hyperpolyglot.org/) actually).

<comment><AUTHOR> Thank you - that is an amazing resource you linked!

</comment></comment><comment><USER12> Try doing the string manipulation section for Zsh instead ;) It will kill you.

[http://zsh.sourceforge.net/Doc/Release/Expansion.html](http://zsh.sourceforge.net/Doc/Release/Expansion.html)

<comment><AUTHOR> Think I'll just stick to Bash for now haha xD

</comment></comment><comment><AUTHOR> It's a reference site about Bash scripting, and it's being improved each day since it still has some rough edges. But I'm starting to like the result on desktop resoulution. Next up is improving the CSS for low-res devices and adding toggable color-themes by clicking some radio-buttons or something :-)

</comment><comment><USER13> I bookmarked this as it will be very helpful to me, so thank you!

My constructive or no so constructive criticism is that I really really don't like the theme. I find it really hard to look at and a bit difficult to read.

<comment><AUTHOR> I'm about to implement some common color-themes which'll be easy to toggle (visually/color-wise it'll be like those themes you'd see in an IDE like Eclipse or Intelli-J f.e.). I expect to be finished with the feature in a week or so.

Thank you for the feedback and glad you like the content :-)

<comment><USER14> Echoing that is is a very useful site and echoing concerns re: theme and glad you are giving some options! Specially, I'd like to callout the main problem to address when adding additional themes is that the headers are needless bright while there is very low contrast when it comes to the actual content.

</comment></comment></comment><comment><USER15> Nice reference, compact and complete.

My 2 cents: top menu goes away when you reduce window width; on mobile no menu at all (but content goes one column correctly, so halfway responsive). If you move or click on something, it highlights the cell (not everywhere) but there is no operation/command bound with that (no copy to clipboard or any kind of interaction). Usually, something highlightening represents an action that user can do.

</comment><comment><USER16> There is also 'man bash', you can even search it.

Joking aside, the bash man page is pretty good and well structured.

      man bash | grep '^[A-Z]'

</comment><comment><USER17> Well done! For a first website, this is amazing. I can learn some bash from this site. Also, I want to say it was a pleasure (more relief, really - <USER2> 2020-02-13) to read the comments and not be overcome by negative comments. Sometimes even "constructive criticism" misses the goodness in the gigantic effort to make. Your first website and you get on HN! Go YOU!

</comment><comment><USER5> This looks great!

If I might suggest something: Maybe you'd like to investigate different layouts for different use cases? The alphabetical ordering of builtins e.g. will mainly help you if you encounter it, but don't know what it does.

For more exploratory/educational lookup attempts, perhaps it could be useful to group them together by their use? I'm fairly certain, for example, that grouping `cd` together with `pushd` and `popd` might help someone avoid some rather nasty bugs in their script. Maybe, even a "see also" in the direction of subshells could help (as `cd` only affects the commands in the subshell).

And, on a sidenote: Interestingly, one can find similar "lookup problems" all over the place. For instance, any good guide to morse code will show you an alphabetical list of codes (text -> morse code) as well as a morse tree (morse code -> text) :)

</comment><comment><USER18> I find the scrolling interface strangely satisfying -> useful too, as you can do a full page search via the browser.

Good job!

</comment><comment><USER19> > . expands to the current directory. > .. expands to parent directory.

I don't believe this is true. These aren't expansions, but rather actual objects you can reference that point to cwd and cwd's parent.

You can tell because `echo .` doesn't expand while `echo ~` does

<comment><AUTHOR> Thank you for pointing that out. I'll fix that.

</comment></comment><comment><USER20> I absolutely love this. You have earned a bookmark.

If you ever want to add some useless splash for no reason, can I suggest one of these?

[https://codepen.io/search/pens?q=terminal](https://codepen.io/search/pens?q=terminal)

</comment><comment><USER21> Very nice. I know that it is a bash quick reference, but I was kinda expecting to see an example, at least for each section. Or a different page with a few examples and maybe a simulator. Kinda to see the magic. But it's cool nevertheless.

<comment><AUTHOR> I did do a bit of experimentation with modal dialogs + some highlight-js for code snippets, but decided to skip it for now and fix up all loose-ends. But it's coming at some point. I'm also considering doing some screenrecordings at some point.

What do you mean by a simulator? I think perhaps that'd prove beyond my skill but the idea sounds interesting.

</comment></comment><comment><USER22> Nice. My initial reaction is that the serif fonts are hard to read. Can you try some console or san-serif fonts, or make that configurable? Someone else suggested toggleable themes, so it would go with that.

<comment><AUTHOR> Configurable fonts is a nice proposal - will try that, thanks!

</comment></comment><comment><USER23> Your disclaimer modal doesn't fit on mobile causing the viewport to extend outside expected bounds. Otherwise looks nice.

<comment><AUTHOR> Thank you - fixing the site for mobile devices is on my todo-list and will happen very soon.

</comment></comment><comment><USER24>
        255*  Exit status out of range

I don't know what the asterisk means here, but that doesn't sound right.

<comment><AUTHOR> I'll fix that, thank you.

</comment></comment><comment><USER25> I'm just curious, did you construct these tables manually? I mean did you type those html tags manually?

<comment><AUTHOR> I made a template table which I then added table-rows to by copy-paste and then filling them out.

It was a bit tedious work I must admit.

</comment></comment><comment><USER26> > Placeholder. TODO [Soon-ish].

Not sure how important it actually is, but your privacy policy link has no information :)

<comment><USER27> It's private!

</comment></comment><comment><USER28> cheat.sh is way better method for searching something like

[https://cht.sh/bash+string+slice](https://cht.sh/bash+string+slice)

</comment><comment><USER29> Nice job for a first site! You must have learned a lot about bash while working it :)

</comment><comment><USER30> This has given me an idea for a cheatsheet generator site. I feel a lot of cheatsheets are pretty similar: section, subheader, and a list of keys + descriptions. Could make this an easy little vue app.

</comment><comment><USER31> Gotta say thank you for this resource; I'm always using bash for one thing or another, and this will be a helpful site for the future. I've got it bookmarked for just that reason!

<comment><AUTHOR> Appreciated!

</comment></comment><comment><USER32> really nice, I'm going to use it.

I think there's a mistake in "Access Codes & Permissions", AFAIK (which is not much) the o stands for "others" and now "owner".

<comment><AUTHOR> Fixed - thank you.

</comment></comment><comment><USER33> You list the flags, but are you supposed to guess the commands? For example, on the File Testing Operators section, I can't find a single mention that the command is "test"

</comment><comment><USER34> I like the site! Question, any reason why your internal hyperlinks (<a name>) jump to beneath the header of the section instead of showing the header of the section?

<comment><USER35> This is a common issue when using links to jump to page headings, when the top bar has fixed positioning: [https://stackoverflow.com/questions/4086107/fixed- page-heade...](https://stackoverflow.com/questions/4086107/fixed-page-header- overlaps-in-page-anchors)

<comment><USER34> Ah, and this is why I despise working with CSS/layouting/etc. Thanks!

<comment><AUTHOR> Fixed - thanks.

</comment></comment></comment></comment><comment><USER36> If you're running macOS, remember that built-in bash is from 2007 and won't support all the fancy stuff like ${VAR^}.

<comment><AUTHOR> I'll add a notice about this - thank you for mentioning that.

</comment></comment><comment><USER37> Love the site, love the favicon - nice work!

</comment><comment><USER38> Still waiting for your DNS to propogate :)

<comment><AUTHOR> I reduced the TTL values - thank you for informing. Thought it had propagated, so I increased the values a bit recently.

</comment></comment><comment><USER39> I really want to check this out, but my eyes hurt reading the page because the contrast of gray on black is so low. A vision-impaired person might not be able to read it at all. Please consider using this tool to pick a text color that provides sufficient contrast: [https://snook.ca/technical/colour_contrast/colour.html#fg=90...](https://snook.ca/technical/colour_contrast/colour.html#fg=909090,bg=202020)

<comment><USER40> Chrome inspector shows the contrast as 5.07 which seems to pass the recommended AA 4.5 threshold.

I tried fiddling with the colors in the inspector, if you increase the contrast you start to get something I would describe as burn-in, after images in vision of the lines of text. Very uncomfortable, I actually prefer it with lower contrast.

<comment><USER41> Somehow i doubt it's testing the grey on black when it is getting that number. Or if it is, it's probably being thrown off in averaging out the high contrast of the orange on black.

<comment><USER41> Firefox's accessibility tool doesn't even see most of the text when making its calculation.

</comment></comment></comment></comment><comment><USER42> Looks great! Can you add a feature to copy the flag/notation/etc when you click on it?

<comment><AUTHOR> Good idea! - Try checking back in a week or two if you're interested, and I'll properly have it setup by then.

</comment></comment><comment><USER43> Very nice, thank you - bookmarked!

</comment><comment><USER44> This looks high-quality. I'll definitely battle-test it.

Also I'm loving the animated favicon.

</comment><comment><USER45> I think it would be great to indicate POSIX sh compatibility for every item.

</comment><comment><USER46> Opened the site on my iphone 6S and could not even close the popup.

</comment><comment><USER47> I'm a big fan of the design / color scheme.

</comment><comment><USER48> I love it! Good job!

</comment><comment><USER49> Very useful! thanks for this</comment>


Coronavirus clue? Most cases aboard U.S. aircraft carrier are symptom-free - <AUTHOR> https://www.reuters.com/article/us-health-coronavirus-usa-military-sympt/coronavirus-clue-most-cases-aboard-u-s-aircraft-carrier-are-symptom-free-idUSKCN21Y2GB <comment><USER4> IMHO, this article is intentionally misleading. The incubation period is currently estimated to be 2-14 days (mean is 5.6 days per CDC, similar per WHO). The article doesn't mention any dates or time frames, but does mention:

"Roughly 60 percent of the over 600 sailors who tested positive so far have not shown symptoms of COVID-19" — note how "so far" is ambiguous in that sentence. It also states, "The Navy's testing of the entire 4,800-member crew of the aircraft carrier - which is about 94% complete...", which seems to indicate nowhere near enough time has elapsed to draw any sort of conclusion.

This paper [1] found that testing of all pregnancy patients in a hospital yielded 34% asymptomatic cases. That number drops to 8% "shortly after discharge", and could be lower than 8% (Again, no timeframe is stated).

[1] [https://www.sciencedirect.com/science/article/pii/S258993332...](https://www.sciencedirect.com/science/article/pii/S2589933320300483)

<comment><USER5> Just as one data point, the captain of the ship raised alarms about the virus spreading late last month. So it's not exactly a recent outbreak.

Of course, without testing from that period it's impossible to know.

<comment><USER6> If the virus spreads exponentially, you would expect most cases to be presymptomatic at any given time.

<comment><USER7> Not when the amount of people is limited. Exponential spread in isolated group of 3000 people necessary becomes non exponential at some point.

<comment><USER8> Eh, so far only 600 of the 4800 member crew has tested positive. That should still be comfortably in the "mostly exponential" territory.

<comment><USER9> The article isn't clear what kind of tests these were.

If, as is most likely, they're PCR tests for viral RNA, then they'll only detect active (or recently-active) infections. So anyone who's gotten-over an infection, symptomatic or not, will test negative. The number of infections reported here is a floor on the actual number who have been infected – which could be 2x, 4x, or more.

If instead these are antibody tests, then they're only indicating 600 _total_ infections. But that kind of test is less likely here: such tests are not very useful for diagnosis of active infections, as they only turn positive late in a case. They could be useful for tallying past infected status – but there's a lot of rumbling that early antibody tests haven't been as reliable as hoped.

<comment><USER8> That's actually in the range of possibilities, I guess.

The best current data on the IFR for 20-40 year olds is low enough that you might not get any deaths out of a ship-wide infection[0], so you don't have the same "Where were all the dead bodies if this ran through the population earlier?" question you do for cities and countries.

The current estimate of the recovery time is around 25 days, and the date of exposure is believed to be March 5th. Assuming we're looking at an exact snapshot of infections today, that gives you March 23rd as the day everyone recovered on the ship was infected by, about 18 days after the first exposure. Assuming some small number (~10) were initially infected, that would only require a doubling period of ~2 days, which is shorter than seen elsewhere, but you're also in an ideal environment (close quarters, communal living) for spread.

I don't know if I believe that to be what happened here, but we should hopefully be able to determine it from the data after the fact with further monitoring and testing.

[0] There's been one, and you could have up to around 6 or 10 while being consistent with the current data; more than a couple dozen would raise a lot of questions.

</comment></comment></comment></comment></comment></comment></comment><comment><USER10> Stanford's study should give us more info soon. They recently screened a decent sized group in Santa Clara County to get a sense of how widespread it is, using their newly developed finger-prick test which looks for both antigens and antibodies (whether you have it / had it and recovered). Currently the test is being prioritized for frontline healthcare workers while they work on scaling up:

[https://www.stanforddaily.com/2020/04/04/stanford- researcher...](https://www.stanforddaily.com/2020/04/04/stanford-researchers- test-3200-people-for-covid-19-antibodies/)

<comment><USER11> It's been 12 days since they tested everyone. My understanding is that the results for serological tests are available right away, so I was expecting them to publish results within a few days. Any idea why they haven't yet?

<comment><USER12> Perhaps they can't get statistical significance. You'd ballpark a 0.5% infection rate in the Bay Area going by deaths and current best guesses for IFR. Your false positive rate might exceed that.

These tests are better done in highly infected areas like NYC.

<comment><USER13> > current best guesses for IFR

The entire point of the study is that we don't have good estimates of the IFR.

<comment><USER12> We have randomized PCR studies and ships where everyone got tested. Yes, there is error there (false negatives), but there's an upper bound to how much there can be.

</comment></comment></comment></comment></comment><comment><USER14> 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.

<comment><USER15> If 0.37% is true, why are the hospitals in this shape?

<comment><USER16> Imagine all 65M people in the UK caught the virus then a 10,000 case fatality number would give a rate of 0.015%.

The rate itself has no time element so it tells you nothing about the number of people in hospital right now and hence isn't very illustrative of how hospitals can be swamped by this disease.

More interestingly (for me at least) is that the mortality rate is dependent on a patient's access to a ventilator. This means if you caught the virus early in the spread of the pandemic your odds of surviving are substantially higher than if you caught it right at the peak of infection.

This is impossible to reflect in a simple global mortality rate and so really paints a different picture of the virus - the death rate in South Korea vs other places really highlights this.

I guess to your point, hospitals are more in this way because the virus is so infectious, rather than it being a universally dangerous disease as may be seen from a higher mortality rate. Remember, a high number of people experience little to no symptoms from catching this.

This variability in symptoms doesn't seem to be as true for other lethal diseases like say malaria or dengue fever

<comment><USER17> Though my understanding is that the survival rate of a covid19 patient once he requires a ventilator is around 50%. If that's true, at worst, if we ran out of ventilators, the death rate would double. That's bad and we should avoid it but the doubling of a tiny number will still be a small number.

Which is why I am still confused by the ratio of 1:10 that the White House has shown between the death toll under lockdown vs no lockdown.

For the reason above, I would only expect the death rate to double. No lockdown means a lot more people get infected faster. But lockdown still requires to build herd immunity, we are only slowing it down. So the same number of people will get infected ultimately. So either they implied that the lockdown would be permanent until we get a vaccine (at best 2021 Q1), or it completely disregarded what happened after the initial few weeks of lockdown and then the numbers were at best grossly misleading.

<comment><USER18> We've been on lockdown because approx 1% of the US population has tested positive. That means 99% are not. How can we come out of lockdown when we are effectively still where we started. We're not even close to herd immunity.

<comment><USER19> The actual CDC plan is here:

[https://fm.cnbc.com/applications/cnbc.com/resources/editoria...](https://fm.cnbc.com/applications/cnbc.com/resources/editorialfiles/2020/04/16/WHReopeningDoc.pdf)

It's not just "full lockdown vs no lockdown".

<comment><USER18> Right. So why were we in full lockdown then? I can't imagine 1% is that significant.

</comment></comment></comment></comment></comment></comment></comment><comment><USER20> 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-...](https://www.niid.go.jp/niid/en/2019-ncov-e/9407-covid-dp-fe-01.html)

18% asymptomatic retrospectively: [https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7078829/](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...](https://appliedradiology.com/articles/study-investigates-diamond- princess-cruise-ship-covid-19-findings)

<comment><USER21> Do you know any studies of the outcome of the 32 Diamond Princess patients that were the ICU at the time the boat was emptied? I have been looking and I can't find any data on what was the final clinical outcome of all patients on the Diamond Princess?

<comment><USER22> Wiki said there have been 14 deaths so far, most recently just 3 days ago.

<comment><USER21> It seems they are only tracking the Japanese deaths. It doesn't seem like anyone is tracking the seriously ill who were transported home, or those that became ill once they got home. Even on these incomplete number the true death rate is 2%.

</comment></comment></comment></comment><comment><USER23> 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...](https://www.nytimes.com/reuters/2020/04/16/world/europe/16reuters- health-coronavirus-netherlands-study.html)?

<comment><USER24> 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.

<comment><USER25> 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.

<comment><USER26> 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.

<comment><USER24> Humanity's understanding of this disease is much more sophisticated than the two comments above this would imply.

Researchers are not stupidly looking at Diamond Princess and getting confused because the population is old.

Rather it's a powerful dataset because it enables us to quantify the asymptomatic people of all ages, because people were tested fairly exhaustively before being allowed leave, regardless of symptoms, and because we've had enough time for many of the cases to play out.

The diamond princess data revealed a large number of asymptomatic cases in China, the absence of which were skewing the detected cases in China much older.

Anyway, you don't need to think anything complicated about correcting for ages, etc

You can just look at the data from the Netherlands where they conclude they have 3% population infection, by looking at the random serological testing, and then look at the number of confirmed deaths they have, and do the very simple math.

It's very hard to do that and then say we're missing say 10x higher numbers of asymptomatic cases all over the place.

This blog post I wrote a while back is Ireland specific but has figures on CFR and IFR I think are still valid, and references to the academic articles I got them from: [https://email@example.com/predicting-the-impact-of- cor...](https://email@example.com/predicting-the-impact-of-coronovirus- on-ireland-bff1b6d00d6a)

<comment><USER27> "Humanity's understanding of this disease is much more sophisticated than the two comments above this would imply."

I think we can generalize this to pretty much every comment made in this thread, and others like it, regardless of how certain some of them sound.

<comment><USER28> And quite a few other threads, too :-(

</comment></comment></comment></comment></comment></comment></comment><comment><USER29> 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.

<comment><USER30> Yes. Many institutions test only if preparing to admit. Anybody else is told to go home and recover in isolation.

<comment><USER31> 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.

<comment><USER32> 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?

<comment><USER33> Lots of people in NYC are getting dragged out of their homes in body bags that will never get tested.

[https://www.yahoo.com/news/teams-retrieving-280-bodies- day-1...](https://www.yahoo.com/news/teams-retrieving-280-bodies- day-170100636.html)

<comment><USER34> They are now including many of the suspected (but untested) cases in their reported numbers now. It increased the total from New York by a significant amount, see [1].

The increase is roughly in line with similar estimates from excess mortality [2], so I would guess they are catching most of the deaths with the new reporting scheme.

[1] [https://www1.nyc.gov/assets/doh/downloads/pdf/imm/covid-19-d...](https://www1.nyc.gov/assets/doh/downloads/pdf/imm/covid-19-deaths- confirmed-probable-daily-04142020.pdf)

[2] [https://www.nytimes.com/interactive/2020/04/10/upshot/corona...](https://www.nytimes.com/interactive/2020/04/10/upshot/coronavirus- deaths-new-york-city.html)

</comment></comment></comment></comment></comment></comment><comment><USER35> 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...](https://www.propublica.org/article/what-we-need-to-understand- about-asymptomatic-carriers-if-were-going-to-beat-coronavirus) 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...](https://www.cebm.net/covid-19/covid-19-what-proportion-are- asymptomatic/) for more on how different data points are all over the place.

<comment><USER36> Not to mention. There's a giant filter called basic training which going to skew the numbers. you have a bunch of kids running around in the best shape of there lives and hey what do you know they handle the virus better than average.

<comment><USER37> What about pregnant women? They're known to be more vulnerable to certain types of illnesses (especially viral infections), yet 29 out of 33 pregnant women who tested positive of COVID-19 in NY were still asymptomatic:

[https://www.medpagetoday.com/infectiousdisease/covid19/85965](https://www.medpagetoday.com/infectiousdisease/covid19/85965)

<comment><USER38> Women are less effected overall. It is thought it is due to ACE2 receptor distribution in the body being different than men, but they don't know. However there is statistically significant worse outcomes/disease severity for men.

Pregnant women basically puts the cap of the upper age at around 40. This disease the virus causes in the body is very much worse for those that are older.

The study tested pregnant women admitted to the hospital to give birth. There are a lot of doctor appointments and lab work to check things in their last trimester. So they could've contracted it through those high risk places or routine contact with health care workers who I would say are also high risk.

Still, the study showed _on admission_ that they were positive so they probably didn't get it from the hospital, unless on admission actually means some time after. That assumes it might be able to be detected so soon into the infect as well. It is a bit strange in that regard that it is such a high number.

</comment></comment></comment></comment><comment><USER39> 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.

<comment><USER40> 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.

<comment><USER21> If not done well PCR has an incredibly high false positive rate. If you contaminate your set up area (or equipment) with past PCR amplification material you will get a very high rate of PCR positivity.

Of course if you do things correctly this shouldn't happen, but if the average pathology lab technician is as skilled as my ex-students and colleagues (and myself) then I would be not be so keen to rule out false positives.

Yes there is a major issue with false negatives, especially when the swab was not performed or stored correctly. RNA is not very stable and it is very easy to destroy all the viral RNA if you are not careful.

<comment><USER40> I am familiar with these drawbacks, having worked as a research assistant doing RT-PCR and qPCR. My understanding from a brief stint in industry is that there is a lot more quality control to be found in industrial and diagnostic labs than is typically found in a research lab. So I imagine there is still an appreciable amount of false positives even in a diagnostic lab, but they do have a lot more quality control in place to reduce it.

<comment><USER21> Yes normally this is the case, but when they are under immense pressure to pump through the samples we should expect the normal high standards drop.

</comment></comment></comment></comment></comment><comment><USER41> So people who are fit enough to pass active duty basic training tend not to have symptoms. Solution: put everyone through basic training?

<comment><USER42> Solution: put everyone through basic training. Corequisite Solution: make everyone be 18-34 years old.

<comment><USER43> Carrousel! [https://scifi.stackexchange.com/questions/22080/what-did- the...](https://scifi.stackexchange.com/questions/22080/what-did-the-crowd- think-it-took-to-win-renewal-in-carrousel)

</comment></comment></comment><comment><USER44> 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%).

<comment><USER45> Yep. From the article:

> Still, the case of the Theodore Roosevelt offers a case study for > researchers about how the virus spreads asymptomatically in a confined > environment among mostly younger adults.

...but they don't mention what the average age is. Presumably someone has the data to produce an interesting scatterplot of age versus symptom severity.

<comment><USER46> Average age is probably early 20s. Huge number of first term Sailors between 18 and 22.

</comment></comment></comment><comment><USER47> It's the first time I see news about the aircraft carrier. Could someone summarize why the captain got fired for testing his whole crew in an environment where a lot of people have to live very closely together? My first assumption is that it was a really good decision.

<comment><USER48> He sent an email to his commander and his commander's commander about how the situation was deteriorating... which were then leaked to the press and was promptly relieved of command by Acting Navy Secretary Thomas Modly who later on resigned.

Most people think it was a good call but it also may have compromised the safety of the carrier because now it's known they may be operating under less than perfect condition.

<comment><USER49> The Washington Post managed to get the original letter: [https://twitter.com/DanLamothe/status/1250840016806445056](https://twitter.com/DanLamothe/status/1250840016806445056)

It's pretty clear he was canned by a political appointee for political reasons.

<comment><USER50> Yes and no. He was relieved because he went around the chain of command, which is a universal career-ending move in the military even if you do it for all the right reasons—which he did.

Also, although he was relieved of command, he wasn't "fired" or "canned" or discharged from the Navy. He will undoubtedly go into an early retirement with a full pension at his current rank of Captain. That doesn't change the fundamental unfairness of how he's been treated, but he's going to be fine. And I think he knew and accepted the consequences of his actions.

<comment><USER51> Do you mean e-mailing your commander's commander is a universal career-ending move in the navy?

Or was he discharged on evidence or assumption he leaked to the press himself?

<comment><USER52> Emailing your commander's commander with a groundbreaking complaint is extremely dangerous to your career, yes.

(And not just in the Navy)

</comment></comment></comment></comment></comment></comment><comment><USER53> 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.

<comment><USER54> Especially once you consider all of the pre-existing conditions that make you ineligible to be in the military.

<comment><USER55> 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.

<comment><USER56> Does the mortality rate across entire population (not particular subpopulations) exceed that of the flu?

<comment><USER57> 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.

<comment><USER12> 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](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.

<comment><USER57> 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.

<comment><USER12> 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. - <USER2> making any statement about absolute CFR/IFR.

<comment><USER57> 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.

<comment><USER12> 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/article/PIIS1473-3...](https://www.thelancet.com/journals/laninf/article/PIIS1473-3099\(20\)30243-7/fulltext)

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.

<comment><USER57> There is absolutely plenty of reason for the infection rate to be different by demographic: _we closed schools down_. We don't do that for the flu.

<comment><USER12> We also don't Shelter in place for flu. Bay Area school closure date is 1 day before SIP.

Sweden and Iceland never closed schools for young kids. Data doesn't look any different.

<comment><USER58> Sweden has a substantially higher case fatality rate for COVID-19 compared to other industrialized nations, so it's an interesting case.

</comment></comment></comment></comment></comment></comment></comment></comment></comment></comment></comment></comment></comment><comment><USER59> Now hopefully we can get a better estimate of the range of the latent period. That these cases are asymptomatic does not mean they won't show symptoms at some later date. It also does not mean they are invulnerable to reinfection, and if this virus indeed has Antibody Dependent Enhancement like SARS, this could create an extremely dangerous setup for a second wave with a significantly higher, order of magnitude, death rate.

All of the bits and pieces are floating around in papers, hopefully they won't be confirmed like everything else that started as errant literature.

</comment><comment><USER60> People reading here may be interested in recent UK statistical office data, analyzed here: [https://youtu.be/F39kVKSCP40](https://youtu.be/F39kVKSCP40)

This is data that examines among other things the overall death rate irrespective of reported cause.

</comment><comment><USER61> Is it possible that more people are asymptomatic because the sample population is more athletic? I would imagine there's a certain physique that's maintained and required for the military.

</comment><comment><USER62> 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?

<comment><USER63> 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.

<comment><USER62> 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.

</comment></comment></comment><comment><USER64> This was what was coming out when it was blowing through China, this was what the big concern back February. This isn't news. A good deal of people will never notice they have it which is why the spread of this thing is so difficult to contain.

I guess maybe people doubted it really was that hard to stop or were not paying attention before, but its why its is absolutely critical everyone isolate even without symptoms.

</comment><comment><USER65> Nothing new here. People were talking about asymptomatic spread by younger people for _months_. Why is Esper surprised?

</comment><comment><USER66> Nowhere does the article mention which kind of test was run. Was it qPCR or serological?

The latter tests whether you have had an infection. The former tests whether you currently have one.

The distinction between _presymptomatic_ and _asymptomatic_ is tricky as well, but is less of an issue with a serological test than a qPCR.

</comment><comment><USER67> Could past infections from other corona viruses be Protecting people? I'd like to see research on that.

<comment><USER68> Like [https://en.wikipedia.org/wiki/Human_coronavirus_NL63](https://en.wikipedia.org/wiki/Human_coronavirus_NL63).

"Human coronavirus NL63 (HCoV-NL63) is a species of coronavirus that was identified in late 2004 in a seven-month-old child with bronchiolitis in the Netherlands.[1] The virus is an enveloped, positive-sense, single-stranded RNA virus which enters its host cell by the _ACE2_ receptor."

To add, I also wonder whether those with contacts to disease super spreaders (aka toddlers in kindergarten) have better immunity against covid-19, just by being previously infected by other coronaviruses. Possibly some currently unknown ones as well.

</comment></comment><comment><USER69> Let me cite full abstract of the research on CT scans of symptom-free COVID-19 patients [1]

Purpose

To evaluate the chest CT findings in an environmentally homogeneous cohort from the cruise ship "Diamond Princess" with Coronavirus Disease 2019 (COVID-19).

Materials and Methods

This retrospective study comprised 104 cases (mean age, 62 years ± 16, range 25-93) with COVID-19 confirmed with RT-PCR. CT images were reviewed and the CT severity score was calculated for each lobes and the entire lung. CT findings were compared between asymptomatic and symptomatic cases. Results

Of 104 cases, 76 (73%) were asymptomatic, 41 (54%) of which had lung opacities on CT. Other 28 (27%) cases were symptomatic, 22 (79%) of which had abnormal CT findings. Symptomatic cases showed lung opacities and airway abnormalities on CT more frequently than asymptomatic cases [lung opacity; 22 (79%) vs 41 (54%), airway abnormalities; 14 (50%) vs 15 (20%)]. Asymptomatic cases showed more GGO over consolidation (83%), while symptomatic cases more frequently showed consolidation over GGO (41%). The CT severity score was higher in symptomatic cases than asymptomatic cases, particularly in the lower lobes [symptomatic vs asymptomatic cases; right lower lobe: 2 ± 1 (0-4) vs 1 ± 1 (0-4); left lower lobe: 2 ± 1 (0-4) vs 1 ± 1 (0-3); total score: 7 ± 5 (1-17) vs 4 ± 2 (1-11)].

Conclusion

This study documented a high incidence of subclinical CT changes in cases with COVID-19. Compared to symptomatic cases, asymptomatic cases showed more GGO over consolidation and milder extension of disease on CT.

[1] [https://pubs.rsna.org/doi/full/10.1148/ryct.2020200110?fbcli...](https://pubs.rsna.org/doi/full/10.1148/ryct.2020200110?fbclid=IwAR10SZ4I0ORtt5eu9wz55JaMJLfeRhg- mgfNsABwnbksoSClINKVXvHA7OU&)

One with asymptomatic illness very probably (3/4) will get lungs damage.

<comment><USER70> When you say damage, do you mean permanent damage? Or maybe it is still not clear?

<comment><USER71> permanent [https://www.nationalgeographic.com/science/2020/02/here- is-w...](https://www.nationalgeographic.com/science/2020/02/here-is-what- coronavirus-does-to-the-body/)

<comment><USER70> Thanks for the link! My question was more into the direction whether permanent damage can occur in mild/asymptomatic cases and it looks like it is not the case. Anyways, if I am wrong and anyone has better information on this, please share it.

</comment></comment></comment></comment><comment><USER72> Is there any info on the sensitivity/specificity of this test and/or on how they confirm that positive results aren't false positives?

</comment><comment><USER73> 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.

<comment><USER74> 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.

<comment><USER73> > 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

<comment><USER75> 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 excellence

<comment><USER76> I too am a 'pretty sure I had it already' person. I have also spoken to others that, like me, think they might have had it already.

In the weeks before the story went crazy I bought a dehumidifier in the belief that this might help me eradicate a dry cough that would not go away. Not for one moment did I think I had coronavirus at the time, however, as time went on, I began to wonder. Placebo or not, the dehumidifier was an extraordinary measure and my symptoms had been remarkably similar to those of the dreaded disease.

Because none of us were tested and because we didn't go to hospital we can be readily dismissed by those that only believe the TV news.

The founding myth is also a bit odd. We have a flying mammal - a bat - <USER3> the disease on to an ant-eating mammal nobody ever sees in zoos - the Malayan pangolin - for this creature to be smuggled into China to then make it to a seafood market to then infect Wuhan. The sources for this are lacking and it is lazy reporting dressed up as science. I am surprised Father Christmas isn't in there somewhere.

The Spanish Flu of a century ago was only called that because neutral Spain wanted to know what was going on with the flu whereas the warmongering nations were blind to the epidemic that was wiping out their troops. There is a theory that the Chinese folk brought in to dig the trenches of WW1 were the source of the so-called Spanish Flu.

I am open to the idea that the Chinese happened to do the research and pick up on covid-19 first, hence the idea that it came from Wuhan. But did it really? There are 7 billion or so humans with many billions of intensively farmed animals yet it was some endangered species that doomed us all? I am increasingly believing the anecdata is stronger than this 'pangolin story'. I am definitely open to the idea this virus was doing the rounds outside China although there is no proof. However, I see this as like the Spanish Flu, now believed to have not started in Spain.

There is a Chinese saying about people too afraid to eat food in case they choke on it. Right now we are on track for everyone to stay indoors for eternity lest a Baby Boomer get it.

<comment><USER77> Same, I had it starting January 4th in the SF (North) Bay Area, I'm about 90% sure.

I was probably basically a super spreader too, tbh. I went to work every day, 'cause I tend to power through whatever is thrown at me. At least I avoided shaking hands.

People were even talking about it back then... they didn't know it was Corona, but friends I know who are nurses were saying there is a "weird, bad respiratory infection" going around, and a lot of "atypical pneumonia" and a "really bad flu season but it's a weird flu".

We already had it weeks and weeks before the shelter-in-place in the Bay Area, I'm very sure.

<comment><USER78> There is strong evidence COVID-19 was not circulating in the Bay Area in January. Samples collected by the Seattle Flu Study in Jan/Feb 2020 have been retested and COVID-19 was not found before Feb 21. As Trevor Bedford says, had COVID-19 been circulating in CA it almost certainly would have showed up quickly in WA. There is other evidence based on the genetics of sequenced viruses. Details: [https://twitter.com/trvrb/status/1249414291297464321](https://twitter.com/trvrb/status/1249414291297464321)

<comment><USER77> Thoughts?

[https://www.straitstimes.com/world/united- states/coronavirus...](https://www.straitstimes.com/world/united- states/coronavirus-bug-circulated-in-us-weeks-earlier-than-thought-mistaken- for-flu)

</comment></comment></comment></comment></comment></comment></comment></comment><comment><USER79> Super healthy trained people can fight the virus easier? Who would have thought...

</comment><comment><USER80> While this is interesting...

* Sailors are not in any way representative of the general population.

* Sailors in the US Navy are notoriously overworked and there is a strong culture of working when sick. So we're they actually asymptomatic or did they report for work shivering and sweating and semi delerious?

</comment><comment><USER31> 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.

<comment><USER81> 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...](https://www.n-tv.de/wissen/Heinsberg-Studie-entraetselt-Coronavirus- article21704605.html)

<comment><USER82> 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)

<comment><USER83> 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.

<comment><USER82> 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/covid-19-d...](https://www1.nyc.gov/assets/doh/downloads/pdf/imm/covid-19-deaths- confirmed-probable-daily-04152020.pdf) [1][https://covid19tracker.health.ny.gov/views/NYS- COVID19-Track...](https://covid19tracker.health.ny.gov/views/NYS- COVID19-Tracker/NYSDOHCOVID-19Tracker- Fatalities?%3Aembed=yes&%3Atoolbar=no&%3Atabs=n)

<comment><USER31> 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.

<comment><USER84> There's also the problem that healthy young adults are generally very stupid when it comes to assessing risk. Sure, they're probably only at mild risk of days of debilitating hospitalization, but they're also going to be fairly careless about people at greater risk around them.

Locking everyone up gives us a chance to gather data, prepare treatments, and find a way to protect those at risk. Letting spreaders run around carelessly will not make anything but the economy better.

</comment></comment></comment></comment></comment></comment></comment><comment><USER85> We can't tell anything from the article. * We don't know how many people were tested. * We don't know how many people tested positive. * We don't know the false positive rate for the test.

<comment><USER86> > We don't know how many people were tested.

> We don't know how many people tested positive.

Both of those are in the article.

</comment></comment><comment><USER87> Might also be important to note that sailors on an aircraft carrier are primarily college-aged.

<comment><USER88> Also 0% with asthma, obesity, diabetes, etc.

<comment><USER89> Not true. For various reasons, the military grants medical waivers and allows some people with asthma and other afflictions to remain enlisted.

<comment><USER46> Asthma, no. Diabetes, no. There is not a single person on that ship with either, they're both disqualifying from shipboard service.

There are probably some people who are overweight to a varying degree, but again people who get overweight and don't get back within standards get removed from the Navy.

</comment></comment></comment></comment><comment><USER90> Is this related to the three strain theory?

</comment><comment><USER91> There's another air craft carrier in france where 1/3 of soldiers got it.

That said, soldiers everywhere are young and healthy , and usually vaccinated extra

</comment><comment><USER92> Clue to what? Are we still pretending this isn't an old people, unhealthy people sickness?

</comment><comment><USER93> >> 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.

<comment><USER94> 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...

<comment><USER95> A sailor in the Navy is anyone that's not an officer

<comment><USER46> A Sailor in the Navy is anyone in the Navy, period.

And it's capitalized.

</comment></comment></comment></comment><comment><USER96> Young people in the best shapes of their lives tolerate C19 well. I thought it was common knowledge.

</comment><comment><USER97> 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.

<comment><USER98> > 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.

</comment></comment><comment><USER77> I'm calling it now, I bet many people (>20%) have had it, whether they realize it or not.

To be honest, I think it was all over the Bay Area in late December, Early January (when I'm pretty sure I had it) and Feb.

<comment><USER99> I thought the same thing until this afternoon.

In January I fell extremely ill, covid symptoms, including lower right lung pneumonia.

Today I tested negative for covid and antibodies. It seems to have been just a coincidence with a bad viral season.

<comment><USER100> Where were you able to test for antibodies and how accurate is this test? Asking since AFAIK, now widespread testing exists right now.

</comment></comment></comment><comment><USER101> This is not news. The same was already reported one month ago in the Italian village of Vo, where the entire population was tested for Corona. Summary is here: [https://www.bmj.com/content/368/bmj.m1165](https://www.bmj.com/content/368/bmj.m1165)

"In an open letter to the authorities in the Tuscany region,1 Romagnani wrote that the great majority of people infected with covid-19—50-75%—were asymptomatic, but represented "a formidable source" of contagion."

In the same report was another interesting paragraph as well:

He noted that Romagnani's findings appeared to contradict a WHO report based on covid-19 in China.2 This suggested that "the proportion of truly asymptomatic infections is unclear but appears to be relatively rare and does not appear to be a major driver of transmission."

edit: really, downvoted? Because of the mentioning of China?</comment>