Corona virus general questions mega thread

[Strange]

2 minutes ago, Phys1 said:

Can obese cure medicine be used to treat Covid-19 because the cure deals with fat reduction and the virus has a fat layer?

Almost certainly not.

[J.C.MacSwell]

2 hours ago, Strange said:

Almost certainly not.

[Kartazion]

What do you think about that ? 'Minuscule traces' of virus in non-potable Paris water

[CharonY]

That is to be expected. If a lot of people are shedding, it will end up in the sewer system and can be detected with sensitive methods. 

[Kartazion]

4 hours ago, CharonY said:

That is to be expected. If a lot of people are shedding, it will end up in the sewer system and can be detected with sensitive methods. 

That's not sewage right there. But this is clean water to clean the streets of Paris contains virus. 
 

[joigus]

This may be a silly question, but just in case.

Can someone tell me if there is the possibility of using RNA-splicing endonucleases like the ones referred to at,

https://www.ncbi.nlm.nih.gov/pubmed/18217203

to target specific sections of a known virus in order to deactivate it inside the cell in a similar way that restriction enzymes in bacteria function against their bacteriophages? Maybe by designing or selecting them to look for very specific viral sequences but long enough so that they have a very low repeat probability? Or maybe by methylating the sensitive areas in the self RNA? I don't even remember if RNA is susceptible to methylation, which DNA is.

Or maybe both? Is that even possible?

Or maybe too out there.

I'm not even sure this is the proper place to pose this question. I'm sorry if that's the case.

Thanks a lot in advance.

Edited April 20, 2020 by joigus
mistyped

[CharonY]

1 hour ago, Kartazion said:

That's not sewage right there. But this is clean water to clean the streets of Paris contains virus. 
 

No, but the water is drawn from the Seine and other sources which are downstream from sewer lines (directly or indirectly). Wastewater treatment does get rid of a fair bit via flocculation (if they have such a stage) but removal is not always quantitative.

[Kartazion]

1 hour ago, CharonY said:

No, but the water is drawn from the Seine and other sources which are downstream from sewer lines (directly or indirectly). Wastewater treatment does get rid of a fair bit via flocculation (if they have such a stage) but removal is not always quantitative.

These traces of the virus, even weak, show that Covid-19 is present in the Seine and the Ourcq canal.

[Strange]

1 minute ago, Kartazion said:

These traces of the virus, even weak, show that Covid-19 is present in the Seine and the Ourcq canal.

It shows that detected RNA fragments are present. It doesn't necessarily show that whole virus particles are present. And, even if they are, it doesn't tell us anything about transmissibility.

[CharonY]

30 minutes ago, Strange said:

It shows that detected RNA fragments are present. It doesn't necessarily show that whole virus particles are present. And, even if they are, it doesn't tell us anything about transmissibility.

 

32 minutes ago, Kartazion said:

These traces of the virus, even weak, show that Covid-19 is present in the Seine and the Ourcq canal.

Yes, because they get released from sewer lines. There is a reason why they are considered non-potable. If one is wondering whether splash infections are likely, the answer is usually no, as sewage usually at least gets diluted and the measured titer is generally low. The risk is higher if you drink it, but typically bacteria are the bigger issue.

[Kartazion]

How many viruses does it take, in number of copies, to infect the human body? 
Several? Or just one virus alone is enough to infect the body?

[CharonY]

There is a minimum required, though it is often not well defined (and a bit stochastic, I.e. the more the likelier it is to become infected). But single particles are very unlikely to result in disease.

[Emanuele09]

I have a device that emits UV-C rays (in particular with a wavelength between 260-280 nn) through 8 LEDs.  I researched on Internet and found that in theory these wavelengths should be enough to kill bacteria but also viruses.  I am not an expert and would like to have your opinions.

 1) What I said about wavelength generally apply to viruses?

 2) If this should be right, considering that I don't have anyone to make sure that the device actually has those technical characteristics, would it still be plausible or would you be skeptical?  That is, the technology of UV-C LEDs is widespread and reliable enough?

 Thank you

[Strange]

Quote

Though there hasn’t been any research looking at how UVC affects Covid-19 specifically, studies have shown that it can be used against other coronaviruses, such as Sars. The radiation warps the structure of their genetic material and prevents the viral particles from making more copies of themselves.

...

But there’s a major caveat.

“UVC is really nasty stuff – you shouldn't be exposed to it,” says Arnold. “It can take hours to get sunburn from UVB, but with UVC it takes seconds. If your eyes are exposed… you know that gritty feeling you get if you look at the sun? It’s like that times 10, just after a few seconds.”

To use UVC safely, you need specialist equipment and training. The World Health Organization (WHO) has issued a stern warning against people using UV light to sterilise their hands or any other part of their skin.

https://www.bbc.com/future/article/20200327-can-you-kill-coronavirus-with-uv-light

So, yes it might. But it is very dangerous and it is hard to imagine where it would be useful. What is wrong with soap and water?

[swansont]

There's a Nature article that claims that far UVC isn't an issue for mammalian skin

https://www.nature.com/articles/s41598-018-21058-w

 

its [UVC] widespread use in public settings is limited because conventional UVC light sources are both carcinogenic and cataractogenic. By contrast, we have previously shown* that far-UVC light (207–222 nm) efficiently inactivates bacteria without harm to exposed mammalian skin. This is because, due to its strong absorbance in biological materials, far-UVC light cannot penetrate even the outer (non living) layers of human skin or eye; however, because bacteria and viruses are of micrometer or smaller dimensions, far-UVC can penetrate and inactivate them. We show for the first time that far-UVC efficiently inactivates airborne aerosolized viruses, with a very low dose of 2 mJ/cm²of 222-nm light inactivating >95% of aerosolized H1N1 influenza virus. Continuous very low dose-rate far-UVC light in indoor public locations is a promising, safe and inexpensive tool to reduce the spread of airborne-mediated microbial diseases.

 

This suggests that the longer-wavelength end of the UVC spectrum (and possibly even longer wavelengths from commercial sources, that bleed into the other parts of the spectrum) are the danger. 

*"we have previously shown" has citations to go along with it, in the body of the article. References 13, 14 and 15.

 

So for a source that's 260-280 nm: no don't use it if it exposes you. It's dangerous. But it probably kills the virus, if exposed for long enough.

 

 

[Emanuele09]

10 minutes ago, Strange said:

https://www.bbc.com/future/article/20200327-can-you-kill-coronavirus-with-uv-light

So, yes it might. But it is very dangerous and it is hard to imagine where it would be useful. What is wrong with soap and water?

Yes, I also read that article. But if the say "To use UVC safely, you need specialist equipment and training" 

is really possible that this technology is really easily accessible to everyone?

[swansont]

49 minutes ago, Emanuele09 said:

Yes, I also read that article. But if the say "To use UVC safely, you need specialist equipment and training" 

is really possible that this technology is really easily accessible to everyone?

"specialist equipment" suggests the answer is "no"

The article I linked to mentions "filtered excimer lamp"

This article

https://www.laserfocusworld.com/lasers-sources/article/16571809/lowdoserate-excimer-lamps-in-hospitals-schools-and-airports-could-safely-curtail-spread-of-flu-watch-video

gives details: 207 nm light is emitted by a krypton-bromine (Kr-Br) excimer lamp, while 222 nm is emitted by a krypton-chlorine (Kr-Cl) excimer lamp

(and goes on to discuss the study)

[Emanuele09]

2 minutes ago, swansont said:

"specialist equipment" suggests the answer is "no"

So the devices that are sold on internet are false?

[swansont]

Just now, Emanuele09 said:

So the devices that are sold on internet are false?

note: I have added to my post

I don't know what you mean by "false" and you have given no examples of the devices you are referring to, so one cannot evaluate their claims.

They are probably UVC lights if they say they are, but they also may emit over a large wavelength range, and would therefore be dangerous

[Emanuele09]

1 minute ago, swansont said:

note: I have added to my post

I don't know what you mean by "false" and you have given no examples of the devices you are referring to, so one cannot evaluate their claims.

They are probably UVC lights if they say they are, but they also may emit over a large wavelength range, and would therefore be dangerous

The device is this: amzn.to/3cJY6xp

and is sold as 260-280 nm. I see a discrepancy between this affirmation: "To use UVC safely, you need specialist equipment and training" and the fact that UVC are sold to everyone on internet.  

But you said me 

17 minutes ago, swansont said:

"specialist equipment" suggests the answer is "no"

So if it is as you say, it means that for example the device that I linked is fake, namely it has other wavelengths instead of the declared?

[swansont]

41 minutes ago, Emanuele09 said:

The device is this: amzn.to/3cJY6xp

and is sold as 260-280 nm. I see a discrepancy between this affirmation: "To use UVC safely, you need specialist equipment and training" and the fact that UVC are sold to everyone on internet.  

But you said me 

So if it is as you say, it means that for example the device that I linked is fake, namely it has other wavelengths instead of the declared?

No, I'm suggesting that the device is dangerous to use, and more so without training and safety equipment. Do you have, for example, UV-safe goggles (or better yet, a face shield)? Do you know to wear skin covering when using the lamp, if it is exposed?

Nothing about that phrase suggests it's anything but a source of 260nm-280 nm light. What that phrase suggests to me is that you need other equipment to use it safely, and that's their way of passing liability on to you should you be injured. If you aren't trained, and/or don't get the safety equipment you need, it's your fault, not theirs. They warned you!

A lot of things are available on the internet that are dangerous to use for the untrained. They, too, probably have a safety disclaimer on the package or device. But that doesn't stop people from being stupid.

[Strange]

51 minutes ago, Emanuele09 said:

I see a discrepancy between this affirmation: "To use UVC safely, you need specialist equipment and training" and the fact that UVC are sold to everyone on internet.

You can buy a chainsaw on the Internet. But to use it safely you need training and safety equipment.

[miamiguy79]

Hello to all,

I am hope everyone is keeping safe during these difficult times and wish you the best in the days to come. I am currently investigating what is the best agent in terms of safety and efficacy in order to present a project for a covid19 disinfecting tunnel. My question to you guys is as follows: Is there any disinfecting agent(s), or combination thereof, that is safe on humans to use in a chamber/tunnel setting where fully dressed humans (Doctors, Offficers, Inmmates, etc) walk through and get "nebullized" with said agent(s)

I really appreciate any input and leads on this issue!

[gib65]

I don't get the strategy the world is using to fight COVID19. I get that social distancing and social isolation are ways to reduce the chances of catching and spreading COVID, but what's the ultimate goal? Are we trying to eradicate the virus? Prolong the eventuality of catching it? Are we waiting for a vaccine? What's the criteria for considering the pandemic over so that we can resume our lives?

I don't understand social isolation in particular. It's almost like we think that by isolating ourselves, we're going to be living as isolated "family units" so to speak, such that the only contact we have is with our immediate family and zero contact with the rest of the world, like this:

But this is an unrealistic picture. No group of people can completely isolate themselves from other groups. We all have social connections with people outside our immediate families/groups that we cannot completely isolate from. For example, I'm divorce with a couple children. I work from home. Not being with my children is out of the question. So one might *think* that my little group consists of me and my kids living in our little apartment all alone until the pandemic lifts. But obviously my ex cannot be away from the children any more than I can. So while I have the kids for one week, she gets the kids for the next week. That connects my small group with her. And of course, she can't isolate from her boyfriend who lives with her. And her boyfriend has family too. He can't isolate from them. And his family has spouses of their own. And their spouses have their own families. And the social ties go on and on like this. The picture ends up looking more like a web than isolated bubbles of nuclear families:

This means there is always going to be a path through which the virus can spread to anyone in society.

So if the goal is to quarantine the virus within only those groups that have it until it runs its course, I think this is a poorly thought through strategy.

Is the goal just to prolong the spread, avoid the inevitable for as long as possible? Wouldn't it be better to rip the bandage off quickly and get it over with?

The only realistic goal I can think of is to slow the spread as much as possible until a vaccine is invented. But how long will that take? I guess this is my question (after the question of: what are we doing?). What does it take to create a vaccine? And how long will that take? Once it's created, do we just go out and get it? How will it be delivered to each individual without risking catching a live version of the virus by virtue of having to be in contact with people? And once a person gets the vaccine, is that it? Is he/she free to go about society and resume their life? Or do they still have to isolate because they could still be a carrier?

I'm just not sure what the goal here is, or how we know when we've achieved it.

[CharonY]

Even without vaccine the idea of flattening is to trickle in serious cases into hospitals in a manageable manner. Ripping off the bandaid would result in much higher number of deaths (as on can see during in the earlier stages in Italy, Wuhan and Spain.

Of course initial contact tracing and isolation could have resulted in it burning out, but that ship has sailed.