Why does the coronavirus spread so easily between people?
nature.com
nature.com
Q: Why does the coronavirus spread so easily between people?
A: We don't know yet
The results presented not verified by experiments yet.
"But some researchers are cautious about overstating the role of the activation site in helping the coronavirus to spread more easily. “We don’t know if this is going to be a big deal or not,” says Jason McLellan, a structural biologist at the University of Texas at Austin"
This Harvard health blog provides a few explanations. [0]
[0] https://www.health.harvard.edu/blog/as-coronavirus-spreads-m...
"Where are we in understanding why the coronavirus spreads so easily?"
That's a gross oversimplification of the article. They have identified proteins and associated host-cell enzymes and can postulate why this combination would result in greater spread (and additionally why other organs are affected).
This is so contagious because:
1. Everyone breaths in nearly 8000 liters of air each day
2. Virus are so small that they stay suspended in air for a while, some estimates are 30min (think how smoke stays afloat)
3. We have no innate immunity to this novel virus
https://www.scientificamerican.com/article/why-do-we-get-the...
In a binary sense, yes it “is spreading”. Even an R0 of 0.1 is “spreading”. But there is hardly enough data to say it is spreading widely in Australia.
The virus spread in summer/tropical vs winter/non-tropical regions is orders of magnitude different. But this is also not definitively causal. Just extremely highly correlated.
But some random person of uncertain credentials says "It's really not hard to grasp why it would spread quickly".
If you have some kind of expert credentials with serious evidence, then it would be great to hear it. Otherwise your opinions are just unhelpful, potentially dangerous noise - and the internet has no shortage of those already.
That's not needed to make judgements on why this virus could be spread easily.
2,113 gallons / 8,000 liters
1,849 gallons / 7,000 liters - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3357553/
2,642 gallons / 10,000 liters - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4398662/
2,642 gallons / 10,000 liters - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4448375/
3,000 gallons / 11,356 liters - https://www.nasa.gov/mission_pages/cloudsat/news/air-water.h...
3,963 gallons / 15,000 litres - https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4398662/
https://www.google.com/search?q=site:ncbi.nlm.nih.gov+liters...
A clearer headline would be: "Scientists are trying to understand why the coronavirus spreads so easily between people."
So if that is the only conclusion, at least there is an authoritative one published.
He looks at it from a scientific and pragmatic point of view, without typical media hyperbole. He’ll often get info from doctors on the ground. He’s been posting videos on COVID-19 since January.
Given the background prevalence of influenza it might be hard to compare, but does it actually spread more easily than influenza does? Is that a conclusion we can already take? For sure it seems to be spreading faster than SARS did, but I don't know if SARS was considered "easy" in this regard either.
e.g. https://www.cbsnews.com/news/norovirus-outbreak-hits-royal-c...
Based on those numbers alone we can be pretty sure that it would have infected everyone on a boat.
If this coronavirus will have the same spread, we could be talking of 19,600,000 to 42,000,000 deaths, or even more if the infections happen all at once and overwhelm the hospitals.
So let's hope it's not as contagious as H1N1 or we're fucked.
I guess it could be worse. We could be talking of the Spanish flu, which killed more than 1% of the world population.
We do have numerous examples of noroviruses infecting a lot of people on cruise ships.
I don't know. I might just be horribly, horribly naive. That is not meant to be sarcastic, but an actual possibility. But I really do feel like if we cannot trust institutions like the WHO, then we have zero facts and everyone can just come up with their own facts/form their own beliefs about this disease. I guess the one thing everyone is on the same page about is that we should wash our hands more frequently ...
Maybe I'm grossly naive too, but it seems incredibly myopic to assume that everything coming out of the WHO is now immediately suspect when the facts are pretty clear that we just don't know much about this virus and probably won't for quite some time. There have been one or two early papers coming out questioning how transmissible the virus is, but I think the data is just too limited.
Without the World Health Organization, we're left with the CDC... and not much else.
FWIW the Gates Foundation was also going to donate $20 million to the WHO[2].
[1] http://www.china.org.cn/world/2020-03/08/content_75787774.ht...
[2] https://observer.com/2020/02/bill-melinda-gates-donate-100m-...
WHO currently represents the scientific consensus.
I'd rather be on the side of the scientific consensus rather than entertain unfounded accusations of corruption promoted by random weirdos on YouTube.
our cells have a "fuzz" of molecules around them refered to as a glycocalyx, and the influenza virus can digest its way through the glycocalyx, using the neuraminidase.
coronavirus doesnt have this feature to assist in fusion and entry.
SARS was effectively stopped because fever developed quickly so it could be easily detected.
Rubeola, pertussis, and TB are all incredibly infectious (R0 > 10) because they are truly airborne. They essentially can survive and still be very infectious in a desiccated form that can float in the air for a long time.
Molecularly you can look at the ID 50 (infectious dose) required to start an infection.
Epidemiologically speaking there can be broader causes like temperature stability, length of illness, severity of illness, amount of virus production, induction of coughing, etc etc.
My bet is on non molecular epidemiological reasons
This had a couple effects:
1. It meant that it didn't spread as quickly because people were already bedridden during the worst phase
2. It was most dangerous to medical personnel. In fact, one of the top experts was infected while treating patients and it was considered a big deal. If an expert following top protocols to the letter could get infected then there was cause for worry.
- dont wear masks, save them for the actual sick. For a disease most people dont know they have and incubates for days seems like the advice should be “wear a mask if you have a cough”.
- dont cough on your clothing, cough into tissues, toss them and wash your hands. This seems almost impossible given most people seem to cough multiple times a minute. Why not teach them to contain the spray. Eg Best: Dont go out. Next best: wear a mask. As a last restort, cough into your shirt (as in pull the collar up over your mouth an cough down inside the shirt so the spray is contained inside it).
Also it's pretty hard to wear a mask correctly. I've seen plenty of people wearing surgical masks with their nose out. If you aren't going to wear that mask correctly, then what's the freaking point?
And even if you can train yourself to wear a mask correctly, to properly dispose of it, etc, the price of masks, even surgical ones, has gone through the roof and even if you can afford to wear a new one each day or two, the supply of masks isn't reliable.
So I'm afraid that at this point, even if you have a cough, the best you can do is to isolate yourself, because masks are in short supply and expensive.
Is that your own co-relation?
For e.g. Influenza Type B versus Influenza type C. Type C is not as contagious and the seasonal flu vaccine does not cover it.
>Rubeola, pertussis, and TB are all incredibly infectious (R0 > 10) because they are truly airborne. They essentially can survive and still be very infectious in a desiccated form that can float in the air for a long time.
Being contagious doesn't directly co-relate to being equally harmful. For e.g. Most healthy adults can easily deal with TB. The numbers shift, but approximately over 40% of the Indian population is infected with TB.
https://www.news-medical.net/news/20200211/Coronavirus-can-l...
which references:
https://www.who.int/docs/default-source/coronaviruse/situati...
https://www.journalofhospitalinfection.com/article/S0195-670...
First, let me say that although the government doesn't formally recognize me as a doctor, I watch a lot of medical stuff on TikTok so I'm basically getting my MD 7 seconds at a time.
That aside, this seems dubious to me; if anything it's likely better to take ACE inhibitors now so that your body makes more ACE2 receptors before you get the virus. One of the ways the virus kills people is by detroying their ACE2 receptors, which your lung cells need in order to function. Downregulating them is unlikely to prevent the virus from getting into your cells, rather it will just leave your cells with less healthy ones left over after the virus destroys the ones it uses to enter your cells.
As evidence from this epidemic, smoking cigarettes upregulates your ACE2 receptors, and smokers are less likely to get serious illness from COVID-19. Of course if they do get seriously ill then they're more likely to die, but this is probably just because of the lung damage caused by smoking. At the very least it seems irresponsible to put out a statement like this without saying that all the available evidence currently points the opposite way, as does the evidence from the SARS epidemic.
Source? I thought the contrary.
* Initially it looked like maybe smoking was a notable risk factor.
* Then some data from a different population seemed to indicate maybe smoking was protective.
* Then further analysis indicated that all this data was likely skewed by upstream sampling bias (like pretty much all CV19 data so far).
* The latest speculation is that maybe smoking makes one less likely to catch CV19 but if you've are a heavy smoker currently (or recently), once you have CV19 your outlook is worse (but nowhere near as bad as being over 60 or immuno-compromised). This was based on a more recent study which seemed to have better data because it went narrow and deep on a few cases, however, it has the disadvantages of small sample size.
* My best guess is that the last bullet might be directionally correct but effect size is small enough that it could easily be swamped by other factors.
In general, us "armchair analysts" obsessively scraping the raw data sources and modeling on it quickly realize that all of the data is very noisy since different regions are using different criteria for what counts as a "case", "severe" and even "hospitalization". Plus no country is sampling the population in a consistent way because they have different criteria to get a test (which can also change daily and by area). For example, Italy's numbers look really troubling in terms of severity and progression until you look at the median ages of who they are testing, which skews 13 years older than their overall population.
I was curious if anything comes out of it, but I guess there's still nothing significant.
Source? Genuinely interested
> Consistent with earlier results, the few smokers who do get diagnosed sem to be more likely to progress to severe illness (3/5 vs ~1/5 expected). https://www.reddit.com/r/COVID19/comments/fdb2g6/new_study_r...
This has a really interesting double effect if you think about it. In places with lots of smokers, fewer people will get the disease, but a larger proportion will die from it. Both of those effects will magnify the death rate.
Edit: assuming the protection is additive and not proportional to existing rates across ages
I imagine that, depending on the mechanism of action, and whether the "increased immunity" remains, there could something reproducible to reduce transmission.
Edit: thanks for the links, guys!
* https://www.kaggle.com/brendaso/2019-coronavirus-dataset-012...
The WhatsApp group is likely to have a source
"1 person out of 200 people who are exposed to a COVID-19 positive individual, will become COVID-19 positive (0.5% transmission rate in the general public)"
As a layperson, I feel I know very little about how SARS-CoV-2 spreads from person to person, especially given that asymptomatic persons are communicable.
If you really want to understand what's going on with CV19 you can try reading the pre-print papers posted at www.reddit.com/r/COVID19 which is a heavily moderated science-focused sub. The analyses posted by users down thread often contain links to even more recent source data.
I've learned an enormous amount there (and also how inaccurate media headlines can be in a complex, rapidly-evolving situation like this).
From reported cases it looks like certain communities are more endangered than others.
Italians?
I mean, this particular conspiracy theory never seemed at all plausible, but it seems particularly non-plausible _now_.