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Covid 19 virus

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Cerebus:

--- Quote from: Nominal Animal on March 16, 2020, 02:13:54 pm ---
--- Quote from: Cerebus on March 15, 2020, 08:22:24 pm ---I think what you're thinking of is a "cytokine storm". Firstly, there have been no reports of this kind of event being systematically associated with SARS-Covid-2 (Covid-19) like it was with SARS-Covid (SARS) - where it was the mechanism of death for many young otherwise healthy people who contracted SARS. Secondly, by the time you have reached the point where your immune systems have overreacted so much that they are (no exaggeration) tearing your body apart in a cytokine storm you are so unwell that you'll be in ICU or on your way there.
--- End quote ---
The EMCrit project does note that "Emerging evidence suggests that some patients may respond to COVID-19 with an exuberant “cytokine storm” reaction (with features of bacterial sepsis or hemophagocytic lymphohistiocytosis)" and that "Clinical markers of this may include elevations of C-reactive protein and ferritin, which appear to track with disease severity and mortality (Ruan 3/3/20)", which to me means cytokine storms are associated, but not systematically in all patients.

As I understand it, these features they mention refer to fever or lowered body temperature, fatigue and confusion, enlarged and/or sensitive lymph nodes, and signs of general inflammation, including rashes.  That means, in my understanding (which is quite limited!), that the situation is not yet on the autoimmune attack stage requiring intensive care, but more like the immune system is not concentrating on the virus properly.  (I can imagine several ways this could happen, the most likely being that white cells cannot tag/identify the virus or virus-infected cells properly.)

If so, reducing the cytokine storm in its initial phase, before intensive care is actually needed due to the severity of the symptoms, sounds like a good idea to me.  From the rumours from Chinese doctors, I understood that in patients where the cytokine storm itself is in its early stages, with intensive care not yet warranted, high doses of ascorbic acid "showed promise".

I could be wrong here, but since taking high doses of vit C in the short term is not dangerous (as it is water soluble), at worst it is a placebo.  At best, it might actually help a little.

--- End quote ---

First off, you'll always see some examples of cytokine storms if you look at enough patients. It's a known complication of any serious viral infection for certain patients. People's immune systems vary, and some are more prone to over-reaction than others. Ask anyone with allergies (slightly disingenuous as different mechanisms are in action, but it serves as a simple exemplar).

The vitamin C thing is interesting, and I bet Linus Pauling is smirking in his grave. One of the non-specific immune responses is to release highly reactive free radicals as a means of destroying invaders. This does that, but also causes oxidative damage to host tissue at the same time. Remember that in the case of a viral infection it is our own cells that have been commandeered by viral RNA/DNA that are the enemy. So it is inevitable that both 'good' and 'bad' hosts cells get clobbered by this kind of response. Using a systemic anti-oxidant such as vitamin C may well be an effective method of limiting the undesirable oxidative damage - we probably won't know until this is all done and dusted. As you say, vitamin C has very low toxicity and, while it may yet prove to be another folk remedy, the risk/reward ratio for using it looks pretty good.

Stray Electron:

--- Quote from: DrG on March 16, 2020, 01:22:08 pm ---I don't think that this link has been posted before - sorry if it has.

2020.03.12 A Coordinated Boston Response to COVID19

https://externalmediasite.partners.org/Mediasite/Play/45a9a74f18ec45deb338e00ac4cf4e281d

--- End quote ---

   Good article. Thanks for posting.  :-+

donotdespisethesnake:

--- Quote from: SilverSolder on March 16, 2020, 01:34:04 pm ---But the survivalist is still only delaying the inevitable, if he ever intends to interact with another human being ever again...

The time to be a survivalist is when a much more deadly disease spreads, at which point it might be mankind's only hope for avoiding extinction...

--- End quote ---

In this case, if you are <50, the best strategy is to get the disease early as possible. You have a low risk of dying, and you get access to medical resources before they are overwhelmed. If you are over 70, might be better to bunker up and wait for a vaccine, but avoiding all contact for maybe months could be quite hard.

Either way, this would be a good practice run for "The Big One". Work out what supplies you need, how long they keep, how often you need to cycle stock etc.

I think the big problem with prepping is that individuals will be very vulnerable. To survive, you will need to be in a group, and in a location that is defensible. So building a network of like minded people, and scouting for good sites is as essential as having a stock of spam and ammo.

edavid:

--- Quote from: not1xor1 on March 16, 2020, 09:23:05 am ---
--- Quote from: SiliconWizard on March 16, 2020, 02:15:03 am ---Yeah, since big malls and amusement parks are closing, people are trying the outdoors, which is not a bad thing in itself. They'll have to try wild nature though, because typical crowded outdoors such as beaches will be temporarily banned too.

Even wild nature may be a problem soon. Does anyone know if the virus can be transmitted to any other species?

--- End quote ---

so far I read about a dog in Hong Kong that tested positive, but there is no report of pet-human transmission
BTW significant viral load was found in dogs during Ebola epidemic but they didn't find any evidence of transmission to humans

--- End quote ---

I think the most likely explanation is that dogs don't shed enough virus to cause infection.  That could be pretty hard to measure in the midst of a crisis.

Does anyone know if the PCR tests being commonly done by public health services are quantitative?  How about the antibody tests?  I've read articles that mentioned both viral load and detected/not detected results.

DrG:

--- Quote from: Cerebus on March 16, 2020, 02:58:24 pm ---
--- Quote from: SiliconWizard on March 16, 2020, 12:11:04 pm ---I don't know what would differ exactly from humans as to how the virus can propagate, so I'd be interested in more details. Maybe it just doesn't infect/ and thus get through their respiratory system at all?

--- End quote ---

Firstly there's a assumption here that the animal had exactly the same strain that is infecting humans as opposed to a closely related but 'dog targetting' variant of the species.

Viruses are incredibly specific to their host species. If a host cell doesn't express some cell surface antigen that the virus needs to get into the cell, it won't. If a host cell doesn't have the right variant of some enzyme involved in manufacturing or assembling new virions then the virus won't reproduce.

The response to viruses is also highly variable within species. For most people Epstein-Barr virus causes the disease Mononucleosis/Glandular Fever, but in some people (particularly in Sino-Asian populations) it causes a type of leukaemia.

All it takes for a virus to cause/not cause disease, or be infectious/no infectious can be as little as a single gene variation in the host species.

--- End quote ---

I don't know why you would say that when we have so much well-documented viral zoonoses. Maybe I am just not understanding.

"Firstly there's a assumption here that the animal had exactly the same strain that is infecting humans as opposed to a closely related but 'dog targetting' variant of the species."

OK, take herpes B for example. There are clearly documented cases of infection to humans after exposure (scratch or bite) to macaques. Indeed, the macaque is barely symptomatic other than shedding...the human, unfortunately can develop encephalitis in a couple of days. The infected human can also infect other humans.

Same virus. same infection albeit dramatically different effects. What am I missing?

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