Corona virus general questions mega thread

[Danijel Gorupec]

43 minutes ago, CharonY said:

Iirc the Spanish flu put the immune system on overdrive, resulting in massive inflammation, which caused damages.

Does it mean that Spanish flu mortality would be much lower if better symptomatic treatment was available?

[J.C.MacSwell]

7 minutes ago, Danijel Gorupec said:

Does it mean that Spanish flu mortality would be much lower if better symptomatic treatment was available?

Most died of bacterial pneumonia, so better antibiotics would have saved many if available at that time.

[iNow]

15 hours ago, iNow said:

You sample an early patient. You sample a later patient. You compare them. You see how much it’s mutated. You do the same for flu.  You see if covid mutates as quickly as flu. How is this a question for you?

Depends on human behavior 

Another retaliatory neg rep. Give me a break. 

[michel123456]

4 hours ago, Prometheus said:

This sounds like the poisoned drinks problem. Unfortunately it won't work here. In the idealised case where we there is say, exactly 1 in every 100 people infected then it could apply. But for every 100 hundred people we take there is no guarantee of the number of infected people. Sometimes there are none. Most times there will be one. Occasionally there will be 10. It is a random variable itself. Also, the tests themselves have a number of false positives and false negatives which will likely be significant.

Yes that looks pretty much to the poisoned drinks problem. Thank you for your reply.

[Casio]

Here is a Government UK link to statistics etc regarding the virus.

https://www.gov.uk/guidance/coronavirus-covid-19-information-for-the-public#risk-level

[druS]

2 hours ago, iNow said:

Another retaliatory neg rep. Give me a break. 

Odd, looks like you are taking issue with the tone of your own response?

"How is this a question for you" - FWIW, it is simple curiosity, they seemed to have determine stability (lack of mutation) quite early, other corona virus mutate do they not? Surely developing vaccines is a more challenging task if the virus is changing.

[iNow]

3 minutes ago, druS said:

Surely developing vaccines is a more challenging task if the virus is changing.

Agreed, and apologies for my earlier abrasion. 

[druS]

All good. I do appreciate the response.

On human behaviour for a second transmission - presuming that only a small percentage of the population was exposed in the initial transmission, and no vaccine - how is it controlled by social behaviour. Sorry that seems daft. The first time round China "missed" it early, then got it under control with draconian measures. The current advice is wash hands, social distancing, self isolation, etc. But those measu4res during the first transmission (here is Australia anyway), don't seem to be expected to achieve more than "slow it down".

Does it mean that little short of draconian measures are enough until a vaccine is available?

[iNow]

41 minutes ago, druS said:

don't seem to be expected to achieve more than "slow it down".

That’s exactly the objective.

Slow it down...  so we have time to develop vaccines. Slow it down... so we have time to manufacture and ship those vaccines. Slow it down... so we don’t have a million people arriving at the hospital on the same day and overwhelming it. Slow it down... so hospital workers who get sick can themselves be quarantined. Slow it down...  so the elderly aren’t so surrounded by so many densely sick people and so easily infected when they go out to purchase groceries. Slow it down... so only 1 in 10 or 1 in 100 people are sick (instead of 1 in 5 or 1 in 3) when life goes back to normal. Slow it down... so people can recover and not all be sick at the exact same time.

Slow it down... That’s exactly the objective we’re striving toward. 

Edited March 15, 2020 by iNow

[CharonY]

20 hours ago, druS said:

I have read somewhere that Covid-19 is not mutating (rapidly like flu anyway). How do they determine that?

I think it is too early to calculate mutation rates. However, coronavirus have something that is called a proof-reading polymerase. These reduce errors in while they replicate and thereby cut down errors (and hence, mutations). 

Quote

But those measu4res during the first transmission (here is Australia anyway), don't seem to be expected to achieve more than "slow it down".

Right now we are pretty much past the point of containment. Even without draconian measures it can be possible to contain it, some countries managed to achieve that. However, what one need to do is quick testing and near perfect contact tracing. While Singapore, Taiwan and also South Korea did well on that end, many countries (incl USA and Europe) botched that, even with the time bought by China.

[druS]

9 minutes ago, iNow said:

That’s exactly the objective.

Slow it down...  so we have time to develop vaccines. Slow it down... so we have time to manufacture and ship those vaccines. Slow it down... so we don’t have a million people arriving at the hospital on the same day and overwhelming it. Slow it down... so hospital workers who get sick can themselves be quarantined. Slow it down...  so the elderly aren’t so surrounded by so many densely sick people and so easily infected when they go out to purchase groceries. Slow it down... so only 1 in 10 or 1 in 100 people are sick (instead of 1 in 5 or 1 in 3) when life goes back to normal. Slow it down... so people can recover and not all be sick at the exact same time.

Slow it down... That’s exactly the objective we’re striving toward. 

Understand the strategy. What I am not seeing is the social reality here in Australia, and i suspect that Australia has handled the matter better than many countries.

There is an expectation that Summer will see a seasonal die-back in transmission, but here in Australia ALL of CV-19 cases have been contracted in Summer (or the summer shoulder). See rather than a natural die-back we would anticipate an increase in transmission. Currently a lot of thinking is short term eg the recent border closure (term used for convenience, you can enter but must voluntarily isolate for two weeks on arrival) and people are saying "just give it a couple of weeks to settle so we can understand what we are dealing with".

But we should know that while a vaccine can be expected it will be 12 to 18 months. On the shorter scale it means availability of vaccine in the approaching winter of 2021, or on the longer scale deep into that winter. In the mean time we seem to be saying that slowing CV-19 down requires quite anti-social measures on more than a short term basis.

2 minutes ago, CharonY said:

I think it is too early to calculate mutation rates. However, coronavirus have something that is called a proof-reading polymerase. These reduce errors in while they replicate and thereby cut down errors (and hence, mutations). 

Right now we are pretty much past the point of containment. Even without draconian measures it can be possible to contain it, some countries managed to achieve that. However, what one need to do is quick testing and near perfect contact tracing. While Singapore, Taiwan and also South Korea did well on that end, many countries (incl USA and Europe) botched that, even with the time bought by China.

CharonY, are you up to expanding on this a little? For background I have just completed my first biology unit in a science degree where one module was molecular biology. Enough knowledge to pretend to be dangerous lol.

From recollection, a virus is a small chain of either single or double strand DNA or RNA. Am I correct in reading CV-19 as single strand DNA?

The Virus has a consisting created by proteins (I had thought a single species but apparently not). And possibly some borrowed membrane from the host cell. Where does it pick up the polymerase?

[CharonY]

Coronaviruses are RNA viruses. On the RNA strand they encode everything they need to replicate and form the capsids. I have mistyped earlier (ironically i did not proofread) and one of the genes it encodes a proof reading exoribonuclease. It excises mismatched nucleases. Other proteins required for basic processes such as ribosomes  are hijacked from the host rather than being encoded in the viral genome.

[CharonY]

16 hours ago, druS said:

There is an expectation that Summer will see a seasonal die-back in transmission, but here in Australia ALL of CV-19 cases have been contracted in Summer (or the summer shoulder).

That is a bit tricky. For coated viruses folks often see seasonality and it is suspected that at lower absolute humidity the viral particles stay infectious for longer (there are various hypotheses as to why, incl. osmotic pressure, staying longer in the air as aerosols etc., but no definitive answer AFAIK). While seasonality have been observed in various coronaviruses, there have been (as you noted) sustained transmission in humid regions.  So folks by now assume an at best modest slowdown, but not a sharp decline. 

[zapatos]

I have my first known (possible) link to COVID-19. My wife works with a woman who was in the office today. The woman has been at home with her college age daughter all weekend. The daughter's college roommate, who she was with all last week, was just tested for COVID-19. No results I've heard yet, but she fell into the category of those who should be tested.

Anyone know how often those tested come up negative? Just wondering if the right symptoms and other risk factors are a reliable indicator of infection by the coronavirus, or if the symptoms are too close to the seasonal flu.

[dimreepr]

4 minutes ago, zapatos said:

Anyone know how often those tested come up negative? Just wondering if the right symptoms and other risk factors are a reliable indicator of infection by the coronavirus, or if the symptoms are too close to the seasonal flu.

yesterday...

15 minutes ago, zapatos said:

I have my first known (possible) link to COVID-19. My wife works with a woman who was in the office today. The woman has been at home with her college age daughter all weekend. The daughter's college roommate, who she was with all last week, was just tested for COVID-19. No results I've heard yet, but she fell into the category of those who should be tested.

Anyone know how often those tested come up negative? Just wondering if the right symptoms and other risk factors are a reliable indicator of infection by the coronavirus, or if the symptoms are too close to the seasonal flu.

I am Groot...

[zapatos]

14 minutes ago, dimreepr said:

yesterday...

I am Groot...

Get back to me when whatever you've ingested wears off.

[dimreepr]

7 minutes ago, zapatos said:

Get back to me when whatever you've ingested wears off.

Don't you mean Imbibed?

[CharonY]

1 hour ago, zapatos said:

 

Anyone know how often those tested come up negative? Just wondering if the right symptoms and other risk factors are a reliable indicator of infection by the coronavirus, or if the symptoms are too close to the seasonal flu.

That is often a bit meaningless- after all it depends on how many folks are being tested and how widespread it already is and the latter is often an unknown. Symptoms alone are not sufficiently diagnostic. General recommendation is generally to self-isolate. Whether one should or even can get tested depends on how prepared the country is. In some enough test kits are around to test folks even with more than second degree contact. In others it is so limited that barely those in direct contact can be tested.

[iNow]

4 hours ago, zapatos said:

I have my first known (possible) link to COVID-19

Friendly reminder

 

[druS]

7 hours ago, CharonY said:

That is a bit tricky. For coated viruses folks often see seasonality and it is suspected that at lower absolute humidity the viral particles stay infectious for longer (there are various hypotheses as to why, incl. osmotic pressure, staying longer in the air as aerosols etc., but no definitive answer AFAIK). While seasonality have been observed in various coronaviruses, there have been (as you noted) sustained transmission in humid regions.  So folks by now assume an at best modest slowdown, but not a sharp decline. 

So the coating is the protein capsid? (In an earlier post of mine there was a spell correct that changed the word). In west and south coast Aus, the weather is drier and less humidity. On the east coast and the north it is the opposite - but we still get seasonal flu.

Either way we can only expect approaching winter to impact while approaching su8mmer in the northern hemisphere hopefully gains benefits.

Fascinating what we do and don't know.

6 hours ago, zapatos said:

I have my first known (possible) link to COVID-19. My wife works with a woman who was in the office today. The woman has been at home with her college age daughter all weekend. The daughter's college roommate, who she was with all last week, was just tested for COVID-19. No results I've heard yet, but she fell into the category of those who should be tested.

Anyone know how often those tested come up negative? Just wondering if the right symptoms and other risk factors are a reliable indicator of infection by the coronavirus, or if the symptoms are too close to the seasonal flu.

 

Zapatos - from what we are hearing the symptoms could be symptoms of many many things of which only one is CV-19.

FWIW some statistics in NSW Australia - reference: https://www.health.nsw.gov.au/news/Pages/20200316_02.aspx

Total number of tests: 26 964

Tested and excluded: 25 511

Under investigation: 1 282

Confirmed positive: 171

Every country will have a different experience based on how accurate they are with who gets tested, and where they are on the curve. But as above under 1% confirmed approx 95% excluded.

Edited March 16, 2020 by druS
Spelling/grammar

[zapatos]

58 minutes ago, druS said:

Every country will have a different experience based on how accurate they are with who gets tested, and where they are on the curve. But as above under 1% confirmed approx 95% excluded.

Thank you druS.

[CharonY]

1 hour ago, druS said:

So the coating is the protein capsid? (In an earlier post of mine there was a spell correct that changed the word). In west and south coast Aus, the weather is drier and less humidity. On the east coast and the north it is the opposite - but we still get seasonal flu.

The capsid refers to the protein structure that encapsulates the nucleic acid (whether RNA or DNA). Some have additional lipids from their hosts. That latter part is what is considered the envelope.

[Externet]

Good day again.  A couple more...

- What percentage of covir19 infections belongs to the age group of -say under ten years olds- ?  if such is known.

-  Heard from a medical professional :  "No need to test if you have influenza,  you would hardly get Corona"   Can someone explain ?  That sent me way back to the years of Interferon...

 

[CharonY]

I could find some data, but I am not sure what you ate interested in. So far there is no indication that certain age groups do not get sick. Rather the age distribution follows familial infection clusters. If a family with kids get sick, the kids will eventually be positive. They are more likely to only have mild symptoms and may be undersampled.

 

So co-infection with influenza and sars-cov-2 has actually been reported. However one potential  issue is that one test is based on isolating RNA and performing an RT-PCR. If you have a high Influenza titer they influence the detection of sars-cov-2  RNA (with the RT step usually being the limiting factor). Differential analysis can distinguish them but can be difficult for standard test labs.

[xdxd]

so incubation period is the time from when you are first affected until you show the first signs and symptoms. this can vary from 2-14 days with the average of 5 days they found according to studies

i was wondering 

1) if during this incubation period, the virus is contagious

2) also if an asymptomatic carrier is only somebody who is in the incubation period (and maybe covalescent period- after you have the disease but you can still spread it?), *can people in stages such as the prodormal stage and the acute infection stage (the third stage after prodormal stage).