Any claim without sufficient data and reproducible results that the virus is unable to transfer via a surface, to me, borders on criminal negligence, given real research shows this is inaccurate.
As a counter to claim virus is “unable to live on surfaces”:
First link is ambiguous as to if the samples taken were “toxic” enough to result in infection, but the second link makes it clear that virus survives on surfaces for days in quantities large enough to infect someone.
> SARS-CoV-2 RNA was identified on a variety of surfaces in cabins of both symptomatic and asymptomatic infected passengers up to 17 days after cabins
Unless there’s more to this, it doesn’t seem very useful to me. It seems obvious to me that you’ll find some RNA. However it would likely be damaged/fragmented.
I’m not sure about the second reference, it would be interesting to dig out the original study.
— Research found that SARS-CoV-2 was detectable in quantities large enough to be infectious in aerosols for up to 3 hours, up to 4 hours on copper, up to 24 hours on cardboard and up to 2-3 days on plastic and stainless steel.
Human coronaviruses can remain infectious on inanimate surfaces for up to 9 days. Surface disinfection with 0.1% sodium hypochlorite or 62–71% ethanol significantly reduces coronavirus infectivity on surfaces within 1 min exposure time. We expect a similar effect against the SARS-CoV-2.
This meme in the media is the real negligence. This is the biggest blurred distinction they've used to sensationalize headlines. It's like digging up a graveyard and using it as proof that humans can survive for 300 years underground.
I'm quite happy to be over cautious until there's better evidence. It's fairly simple to change my behaviour and with a relatively low cost compared to the risk related to uncertainty over ease of transmission.
I'm not talking about whether to stay indoors or not. I'm talking about the precautions one should take in public spaces. I still need to go shopping but whilst there I'm going to assume all surfaces are potentially contaminated.
Likewise groceries, parcels and deliveries either go into quarantine for 2 or 3 days or they are washed.
Do you believe the point of isolation is to stop the spread or slow the spread? If the point is to slow the spread but ultimately for everyone to be exposed, wouldn’t it make sense to do that as quickly as possible without overrunning hospitals?
At this point new hospital admissions are significantly down from their peak. If the point is to slow the spread but acknowledging that it cannot be eliminated, we’ve in fact over-corrected.
The further you get the cases down, the slower the spread when things open back up, especially if it gives you time to ramp up other mitigations like PPE and test production during the lockdown to bring the R0 value down significantly.
The unmitigated doubling time is approximately 3 days. So for every halving in the overall prevalence you buy yourself 3 days of unmitigated growth in a population with no immunity.
On the testing and PPE front, again I wonder if this is just a feel good notion or if there’s even napkin math to show what scale of PPE and testing is theoretically being deployed and what impact that may have on R0.
But returning to the core point, how long until COVID has runs its course, and at what cost? Can we admit that herd immunity must be reached? As Dr. Birx repeatedly asks, are we at the tip of the iceberg or 25/50/75% of the way through?
No one wants to think about it because I guess it would make an uncomfortable choice obvious. Better to just self-flagellate so we can feel like we’re doing something.
> Saying that live virus is there because viral RNA was found is like saying I must be holding a meatball sub because there's a marinara stain on my pants.
There is no such a thing as a “live” virus. They are just a bundle of RNA in a protein/fat shell. If the RNA was identified it means the shell was intact.
Also they measure active live viruses, and has been shown that some viruses can go dormant and come back to life so measuring an area for a virus may not pick up dormant ones and lead to a result that is a false reassurance as the potential for those dormant virus to come back into life is still there.
But so much we don't know about this new virus strain, hence big rush to learn all these details about this virus as with better understanding, better management and approaches come about.
As for its survival rate on surfaces, we still don't know all the details, but does no harm to just treat all surfaces as infected outside your home and work with that - hence hand washing and not forgetting the details like tap, keys, phone, things you can't avoid touching up to the point you actually get to wash your hands. I'd hate to think how many have clean hands and then turn the tap off with the same hands that turned it on when potentially contaminated. That will be the small oversights that catch people out more.
Hence until we get that data to know for sure science wise, presume the worst and hope for the best is always the only prudent approach.
Dormancy refers to when a host is infected but the virus is not replicating.
There is no "dormant vs. live" distinction for viruses outside of a host as they have no function / biological processes outside of a host. They are just molecular robo-syringes that inject RNA/DNA.
Also refers to viruses dormant without any host, for example https://www.bbc.co.uk/news/science-environment-26387276
whilst an edge-case and it does show that enviromental factors and how a particular virus responds and reacts are still things we are learning about this one.
Heck, may find out that frozen good with contaminated packaging can put the viruses into dormant mode and when you take them out of the freezer, and temperature and humidity level kick it into life. Details like that unlikely, yet still not been ruled out and much science still ahead upon this virus and caught many off guard and on the backfoot, but we love solving problems and the science is starting to get more detailed a bigger picture every day. But still, mindful of not eliminating aspects that have not been totally ruled out is a balance of risk/caution and fair judgement still plays a part.
Dormancy isn't really proper biology jargon, the correct term for what I referred to above is latency.
However, outside of the cell, neither of those terms mean anything.
A virus outside of a cell does nothing, period. It is essentially a USB flash drive with a computer virus in it. Saying a USB flash drive can "lie dormant in a drawer for days" is just silly.
> Heck, may find out that frozen good with contaminated packaging can put the viruses into dormant mode and when you take them out of the freezer, and temperature and humidity level kick it into life.
We won't though, because we thoroughly understand how these things function. There are things that function like that: bacteria.
They just found RNA of the Virus not an active Virus, there is a huge difference. Same goes for Virus in stool, you can detect the RNA but it’s not active anymore. Source: Webasto Study
It's a two page summary. Note that this, and the accompanying press conference (with professional PR team) are it. That is the entirety of the details they have released.
I think it's absolutely crazy and irresponsible to do a press conference on a paper that you haven't even released a preprint of. I really hope that there aren't any issues with the actual publication, because if there are, they're going to cause a great amount of damage to scientific credibility, which so incredibly important right now.
Despite it opposing their previous stance on it? They're now mostly backpedalling, and discrediting the study. Or, at least, how it was presented - but can anyone blame them for that?
— Research found that SARS-CoV-2 was detectable in quantities large enough to be infectious in aerosols for up to 3 hours, up to 4 hours on copper, up to 24 hours on cardboard and up to 2-3 days on plastic and stainless steel.
AFAIK it remains unknown how many viruses are required and where in the human body to get an infection. So 'quantities large enough to be infectious' is probably false.
There are very well defined scientific protocols for what an infectious dose is, used in this research. You can put your “probably false” argument against the contents of the paper.
I was not referring to anything like that, but to the fact that a different amount of different viruses is required to cause an infection. E.g. in this paper it is estimated that influenza A (in aerosol form) requires around 2000-3000 viruses to infect: https://www.hindawi.com/journals/av/2014/859090/#conclusions. On the other hand Noro-viruses can infect a person in much smaller quantities (don't bother finding a reference but you'll find it quickly). All I'm saying that it's unlikely that we know such numbers at this point for SARS-CoV-2 so in the paper you linked they must have used some other definition for an 'infectous dose' than what you'd intuitively think.
Edit: Now that I actually read the paper that OP posted, it seems that they're estimating the half-life of SARS-CoV-2. It really depends on the initial amount of viruses how long it takes to go below some fixed 'non-infectious limit'. So numbers such as '3 hours' quoted in the paper are pretty much meaningless in practical situations where the inital amount of viruses might be much different. It's not that they're trying to emulate a cough or something.
The CDC is currently saying that this virus has an R0 of 5.7. Couple that with the many cases of casual spread (e.g. people who have gotten it with people they have barely interacted with), and the contrarian claims by this German study seem farcical.
More generally: will you please stop posting unsubstantive comments and flamebait to HN? You've done it a lot, and we ban accounts that do it, because it destroys the spirit of curious conversation, which is what the site is intended to be used for.
As a counter to claim virus is “unable to live on surfaces”:
Virus was found 17-days after cabins on a cruise ship were vacated: https://www.cdc.gov/mmwr/volumes/69/wr/mm6912e3.htm
Coronaviruses: How long can they survive on surfaces? https://www.medicalnewstoday.com/articles/coronaviruses-how-...
First link is ambiguous as to if the samples taken were “toxic” enough to result in infection, but the second link makes it clear that virus survives on surfaces for days in quantities large enough to infect someone.