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Comment by rubicon33 | Hacker News Reader

Because the virus can spread on surfaces I think. As well as food, and organic matter.

No. From the CDC:

> It may be possible that a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their own mouth, nose, or possibly their eyes, but this is not thought to be the main way the virus spreads.

> In general, because of poor survivability of these coronaviruses on surfaces, there is likely very low risk of spread from food products or packaging that are shipped over a period of days or weeks at ambient, refrigerated, or frozen temperatures.

https://www.aarp.org/health/conditions-treatments/info-2020/...

The CDC themselves were involved in the study that says you're wrong.

If someone is able to find the source for this info I'd really appreciate it. Just spent like 10 minutes trying to find the paper they're citing but I can't find it and I don't have time to keep looking now. Maybe it isn't published?

It might be this one, actually. This one suggests it can live up to 72 hours on certain surfaces. https://www.medrxiv.org/content/10.1101/2020.03.09.20033217v...

I'd love to have some more data on this if anyone can provide.

>but this is not thought to be the main way the virus spreads.

How does it spread then? Seems hard to believe all these people are being infected through hand shakes or being coughed on.

I'm just going to quote the CDC again, because public health authorities are really the best sources of information we have and I don't want to participate in the "telephone" effect that paraphrasing begets:

> The virus is thought to spread mainly from person-to-person.

> * Between people who are in close contact with one another (within about 6 feet).

> * Through respiratory droplets produced when an infected person coughs or sneezes.

> These droplets can land in the mouths or noses of people who are nearby or possibly be inhaled into the lungs.

https://www.cdc.gov/coronavirus/2019-ncov/about/transmission...

As a non-expert on coughing dynamics, it seems incredible that one person can infect 50 others by this mechanism (reported New Rochelle transmission from one patient, confirmed by contact tracing and testing contacts).

At a carnival party in Germany with 350 guests, more than 40 were infected by a single guest. That gives an idea how well it spreads in enclosed spaces. You can assume there was somewhat close contact, but I've been to business meetings with also at least 5-10 people <6ft from me. That's how it can spread through a company within days.

I have not been to carnival parties for 20 odd years, but as I remember them (in NL/border with DE), everyone is drunk, hugging, kissing (often on the mouth with perfect strangers), vomiting, not washing hands after toilet (is there a toilet even??), falling over each other and also having sex. Maybe times have changed, but if it still is remotely like that I can definitely see someone infecting 40+ other people.

I mean, we have city parties here 'for all the family' which result in everyone touching each other (just as friends mostly of course but still touching hands, shoulders, neck, face, back), kissing (mostly on cheeks with strangers, but you mostly 'friendly' kiss everyone meet/talk/dance with and otherwise shake hands or even both) but all the other factors do apply as well; bad/no toilets, no soap/water, everyone drunk so who washes their hands anyway, vomiting and not being so careful with putting your sleeve in front of your face when you sneeze or cough... I only go during the day to such things if I go at all (when most people can still walk up straight) because it is rather disgusting after a while (I am old; I used to like that when I was young), but I can see a few people infecting basically everyone if they are popular/drunk enough.

Hmm... if this is true: https://www.theguardian.com/science/2020/mar/12/coronavirus-...

How do we explain spreading from asymptomatic people? They're not sneezing.

Droplets from a sneeze can take hours to drop down.

And it’s the small droplets that float around the longest. These penetrate deep into your lungs and get stuck there.

Thanks, that's interesting and not something I've heard before. I think the CDC etc should make this clear : it isn't "an infected person sneezing near you" but "a volume of air into which someone has sneezed in the past few hours". If people knew this I think they would be more inclined to accept the distancing measures.

It gets mathematical and statistical really fast.

So there's a constant conflict between simple and easy to understand but not totally correct info, and scientifically correct but incomprehensible to most info.

Someone sneezing in your face = really bad. Someone sneezing an hour ago vs. touching something they just sneezed on... hard to say which is worse.

I get the statistical mechanics aspect, but surely saying "It can spread through the air in enclosed spaces up to <x> m and for <y> s" is understandable by anyone?

Today I read that it can survive for up to 3 days on some surfaces.

Yes.

very low risk != no risk.

Not sure the CDC is the most credible source at this point

Not sure why I can’t reply to the commenter below. Anyway, here’s a link backing up the parent’s claim, contrary to whatever CDC is saying: https://www.medrxiv.org/content/10.1101/2020.03.09.20033217v...

That study isn't saying anything contrary to what the CDC is saying. Or am I the parent that you're agreeing with, and you meant "regardless of whatever the CDC is saying?"

Maybe I misinterpreted what you meant. Your quote from the CDC said that the virus has poor survivability on surfaces, but the study I linked concluded it can survive for 2-3 days.

These are not mutually exclusive statements. It probably can survive for weeks in rare cases, but if it doesn't do that often it doesn't matter.

Any method of transmission that infects fewer than one additional person on average are effectively negligible on the overall exponential curve.

So yes, it is likely possible that symptomatic people can infect others, and it is likely possible that a contaminated doorknob can infect people for a week, but if these things happen rarely enough, it doesn't matter. The virus will die out if other routes of infection (e.g. the more typical person to person transmission) can also be made rare enough.

I see the point you're making from an epidemiological perspective but, because it's so important to people from an individual perspective to avoid contracting the virus, I have to take issue with your claim that it is likely possible to contract the virus from a surface after a period of a week or even weeks. I haven't seen evidence that would substantiate such a claim. According to that preprint linked above, even a period of one week on a steel door handle is more than six half-lives past the "death" of the last detectable viable COVID-19 virus. The science is not all in yet, and it may indeed turn out that COVID-19 is much hardier than we thought, but until then I don't see how you can say that it "probably can" survive for weeks in some cases.

I apologize if this is coming off as pedantic but the damage being done by misinformation and speculation about the coronavirus is significant, and I don't think it's possible to be too zealous about precision here. Trump's claims that fears were overblown and a "hoax" have been amplified into widespread and potentially deadly skepticism that coronavirus is even a danger. People have suggested various quack cures that at best drain the resources of vulnerable people. Even saying something as seemingly-innocuous as "wear a face mask to reduce your risk" ends up having a devastating impact on healthcare providers who really need the masks but can't source them. We should be listening to public health authorities and mainstream health experts, and taking reasonable precautions, but absolutely refraining from speculation that might have unforeseeable consequences.

The relevant part of the CDC quote was "because of poor survivability of these coronaviruses on surfaces, there is likely very low risk of spread from food products or packaging that are shipped over a period of days or weeks" and the study preprint you linked showed that in the worst case (polypropylene surfaces) no live virus at all was detected after 72 hours while on cardboard it was more like a third of that time (with large error bars).

>most credible source

Which would you say is the most credible source then?

This study [1] says it can last on surfaces for 2-3 days.

https://www.medrxiv.org/content/10.1101/2020.03.09.20033217v...

Which would be consistent with the risk being low for goods shipped from Europe or Asia to North America, right?

That's an un peer-reviewed pre-print.

That might be so, however there are enough names from enough reputable research centers to take it at face value. If we need to wait for printed peer-reviewed journal papers to combat an active pandemic then we might be waiting a while!

China Post has been shipping stuff and spraying it with disinfectant. I don't see why that would be a problem. Also doesn't it take more than 9 days to sail across the atlantic ocean?

A lot of goods travel by air from China. See all Apple products (this is a guess, could be wrong)

You can sail across the Atlantic in 4-5 days on an ocean liner

Containers seem to take >=7 days from Germany's closest international port to Newark, NJ (practically NYC), last time I looked at routes and prices.

Oh, that's probably true. They're optimized for throughput rather than speed.

Ocean liners that carry passengers take 4-5

Actually, to a large extend it's fuel prices that cause these "low" speeds. Many cargo ships can be a lot faster if they have a reason that's worth the massive increase in fuel usage.

That also makes a ton of sense.

standard procedure is to just have cargo sit in quarantine for 14 days or whatever. it's a lot less of a hassle than trying to quarantine people

Seems excessive for viruses. They live nowhere near that long outside their hosts.

Even a day is a long period of time in optimal conditions, and not many situations are close to optimal.

“An analysis of 22 earlier studies of similar coronaviruses, including Severe Acute Respiratory Syndrome (SARS) and Middle East Respiratory Syndrome (MERS) published online this month in the Journal of Hospital Infection, concluded that human coronaviruses can remain infectious on inanimate surfaces for up to nine days at room temperature.”

https://news.trust.org/item/20200228215640-n07fz

It's the "up to" bit that I take issue with.

It's a half-life thing. The larger your initial sample, the longer the sample can go and still have enough infectious ability left.

Scenario: Infected person sneezes over a large area and deposits over a wide area. Then you come by 6 hours later and touch a deposited surface and then 10 minutes later touch your eyes.

Each transition only picked up a fraction of what was left.

And each time period left only a fraction of what was there.

More important to limit travel, limit direct/close contact and clean commonly used surfaces frequently.

And better to avoid replicating the environmental conditions that created the "up to 9 day" figure: low temperatures and low humidity.

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