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The coronavirus pandemic in five powerful charts (nature.com)
77 points by abbracadabbra 13 days ago | hide | past | web | favorite | 80 comments

Is anybody able to explain why there are so few new Corona cases in China? I mean, I know that the Wuhan area was locked down and that this way the outbreak was contained there. But China is far greater than Wuhan alone, and just like the virus was able to spread from Wuhan to the rest of the world, it must have spread to the rest of China as well. And during the recent month it must even have been spreading back from over the border into China.

How come that there are nevertheless only between 40 and 50 new cases per day?

Not to be conspiratorial, but China has a vested interest in seeming as if they've beaten the virus both to their own people and the world abroad. Their lockdown clearly had a strong effect, but after its over the virus will spread again. With that said, I don't see any reason why China would share their numbers. They have a history of lying about this disease, I don't know why we should assume we can trust their data now.

Indeed. China's numbers aren't to be trusted. https://www.caixinglobal.com/2020-03-23/despite-official-fig...

No country's numbers of confirmed cases should really be treated as a definitive and accurate view of total number of cases. UK was estimating theirs was off by a factor of 10-20 not long ago. The lack of testing has resulted in very incomplete data around the world, whether or not there's a political motive behind that.

Agreed. I have some friends here who are fairly certain they had it, based on symptoms. However, the hospital refused to test them because they were "young and healthy" (i.e. no underlying medical conditions to complicate things). 2 of the 3 family members recovered with no outside assistance; the third worsened, so they took her to the ER. Only then did they run a test on her.

The number of infected is way off, which will throw everything else off. You can't figure out mortality rates, infection rates, etc if you don't have an accurate number to start with. Garbage in, garbage out.

> However, the hospital refused to test them because they were "young and healthy" (i.e. no underlying medical conditions to complicate things).

The tests have a high false negative rate, which is one reason some countries are not testing everyone with mild symptoms. The test doesn't give you any useful information in that situation: if it comes back positive you need to self-isolate, but if it comes back negative and you have symptoms you still need to self isolate.

I've been saying for a couple weeks that the mortality rate will turn out to be much much lower if/when we ever get proper data on this. Probably very close to the common flu (0.1-0.2%). But the media companies are all having a great time scaring everyone with their 3% figure in the meantime.

Even South Korea is reporting such low numbers, even Japan.

These two videos show how organized and committed China is to containing this virus.




- Your temperature is checked before entering any store/restaurant/tourist attraction/(sometimes) leaving your neighborhood/(sometimes) at a road block. You must scan a QR code so your location is logged.

- Restaurant workers and public servants are suited up in light haz mat gear.

- Entire neighborhoods have literally been walled off with just one entrance where your temperature must be checked to enter/exit.

- Hotels have shut off central air to prevent the spread

- Ordering food is touch free

- Elevators have tissue paper so there's no direct contact with the buttons

- Offices can only reopen once they have a Covid-19 plan, hand sanitizer, gloves, touch free thermometer, masks, etc. Each employee must log how they got to work.

- much more in the links

The most striking difference is apparently the amount of testing China allegedly does. For lack of a better source scroll down to the graph in the middle here [1]. If anyone has credible data to confirm or deny I'd be interested.

[1] https://www.vox.com/future-perfect/2020/3/12/21172040/corona...

I expect the numbers are all just propaganda.

A week ago there were videos released of the makeshift hospital in Wuhan, where all beds were empty and the doctors were standing in front of the empty hospital taking off their face masks, smiling. Soon after, videos were uploaded by locals showing a very different situation.

Disclaimer: This is my own opinion. The only sources I have for this are the same as yours: social media. So, take stuff with a grain of salt, do your own research and make your own conclusion.

I know plenty of people living in mainland China. Their recover is really not just propaganda. People across the country have been in their homes for months and were quick to cancel all sorts of social events.

Speaking frequently with people living there things do seem to have recovered and life is starting to return to normal.

Where can a person find such videos? You believe they were legitimate, and truly occurred after success had been declared?

Great question, and I'm glad I'm not the only one wondering this. It seems hard to believe that in a situation where almost every single country has it that somehow China kept it confined to one province... Obviously they censor their news and social media, so any information coming from them is questionable to begin with.

Other than incorrect numbers, the second most likely possibility is that they found some effective treatment.

In my opinion, the quarantine just worked.

Here's my thinking. We know the following (maybe my information is not entirely correct, but the reasoning is still valid): 1) a host is infectious for about 14d; 2) the virus survives on surfaces/objects for 9d (this is based on other coronaviruses, but a more recent study suggests it's shorter).

If you want to stop the spread, or reduce it significantly, you need to quarantine people for at least 2 x 14d + 9d.

Why is that? Because, the first infected in each household will stay so for the 14d, and assuming all the other members of the household are infected by the first person, and assuming the infection happens towards the end of the first 14d, for safety, you need another 14d. Plus, you want to make sure the virus is not still active via surfaces/objects, so plus up to 9d.

If you go further and assume that not everyone is infected by the first person to have the virus in the household - so you will have multiple generations of infections - then you need to add maybe another 14d. And so on.

China did some 2 months of quarantine. Chances are very high they actually succeeded in reducing significantly the number of active cases. No need to appeal to conspiracy theories at this point.

Why do we see a resurgence of cases? Because the 14d is just the avg. Some people reportedly can be sick for longer, many can be sick without having serious symptoms, some people don't respect fully the quarantine etc. Because of this, stopping it permanently is going to be very difficult via quarantine alone.

Given how widely differently active cases are asserted (different methods of testing, different capacity of testing, different politics towards testing), and how widely they are also well asserted, this figure has little meaning but for local forecasts; not for comparison between countries.

On the other hand, ICU cases, and deaths cases seem more relevant.

The PRC government is known to be flexible with the truth. They could simply be lying.

People are very determined and cooperative. My parents are in China, basically after 2,3 days since it began it’s all over the news and people got serious about it. My hometown, which is a small city in southern China, people are very cooperative and literally do not go outside as soon as the news broke out. I was also chatting with my parents daily as well to ensure they were at home. I wouldn’t trust the numbers completely as well but I think at least the curve makes sense.

According to the article, China has instituted "one of the greatest infectious-disease containment efforts the world has ever seen":

By contrast, three weeks after the first known case of the disease now known as COVID-19, China had notified the WHO of a spike in cases of a pneumonia-like disease. Two weeks after that, the coronavirus had been isolated, genetically sequenced, and a diagnostic test developed, giving China the tools it needed to launch one of the greatest infectious-disease containment efforts the world has ever seen.

If "one of the greatest infectious-disease containment efforts the world has ever seen" has not resulted in contaiment and the virus has continued spreading, as your comment suggests, we will soon find out -and in a very unpleasant manner.

Or, to not put too fine a point on it: in that case we're in deep shit.

That is exactly how the world got into this situation in the first place. China covered it up and basically said nothing to see there. And the world believed in them and didn't put on guard against them. Until the disease spread to other countries and they no longer could cover it up. Then they say "hey look you have it too!"

Number of cases is unreliable because of how few tests are being done even in a place like China.

However, number of deaths is likely more accurate. Some places like Vietnam, and even Washington state have somehow managed to have a very slow growing number of deaths despite likely having community spread before Italy did.

Very good question, I would too like to hear thoughts on this. My first impression was that the data was simply not being updated anymore. The change was too abrupt, simply doesn't seem natural.

Is it likely that the Chinese are giving false data / simply not testing as thoroughly anymore?

There's every indication that a strict, extensive test and quarantine process can work to limit the spread of the virus, and China's been doing exactly that.

I'd expect pockets to crop up here and there, but they know how to shut them down once detected, and have the oppressive infrastructure in place to do so.

Right? The virus has to have a host. With people able to leave their homes and move about, it seems that the number of cases are just going to return to increasing now.

Shangai was in full lock down when there were less than a hundred confirmed cases. This is far more drastic than what any western country have done.

If you are skeptic about China's data (which is a fair objection), you can also look at the Japan process.

They implemented very harsh measures that are currently unthinkable in western countries.

In Spain and Italy the police is patrolling the streets and everybody who is outside without a valid reason can get a fine. Still the virus is spreading like crazy.

The virus spread _before_ the quarantine became serious enough. People just didn't take the quarantine seriously.

I live in Czech Republic, and I read in the news that some 16.5k Czechs went on vacation to Northern Italy _after_ knowing about the risks. Now we're all in quarantine, with plenty of restrictions. Numbers of infections are still very low, but so is the number of tests that were done.

People just did not take Covid-19 seriously.

In Italy the national lockdown was announced on March 9th, so 16 days ago. Today Italy reported 5210 new infections. So the government measures might have some effect, but nothing like in China.

I don't live in Italy so for me it's hard to judge, but could the difference in efficacy maybe be explained by the discipline of the people?

It takes like two weeks between measures being taken and them having an effect on the number of confirmed infections.

Can you tell that to my governor? 'cause every couple days she's throwing more things in, based on how "ineffective" the previous orders were. It's like, I get it, we need to contain the spread. But stop saying that you're doing this new thing because the rates are still climbing so obviously this thing you did two days ago didn't work. Maybe it didn't, but two days is not enough time to know.

Maybe she already knows that but needs to justify the harsh measures to her voters and uses the salami tactic intentionally.

One difference is the timing. Lockdown in Spain and Italy happened too late. Also is it still spreading or are the new cases the result of the incubation period for the disease?

As far as I know, the way how cases were counted changed three times since the beginning of the pandemic in China.

However, I have no idea about the accuracy of their measurements or degree of correct reporting.

I don't know, but you should also be wondering why it isn't worse in Japan. There are some obvious ideas like bows instead of handshakes, but it doesn't seem fully explained.

There two comparisons to other diseases appear to contradict each other. First: COVID-19 is both less communicable and less fatal than SARS. Second: it has spread faster and killed more people than SARS. I would like to understand how both can be true.

Some quick things, the R0 doesn't specify the time it takes to spread, just the number of people that get infected per already infected person on average. A disease that has an R0 of 3 but that takes a month to become infectious would spread slower (to begin with) than one with an R0 of 2 but infectious after day 1.

A lower fatality rate in a higher population can cause more deaths. 10% of 1000 is smaller than 5% of 1000000.

But more importantly, something that is more obvious and more quickly restricted will spread less. SARS had an R0 of 2-4 but with control measures in place that dropped to 0.4 (figures from Wikipedia).

Is there another measure that takes these other factors into account? It's very easy to look at these comparison charts and conclude there shouldn't be anything to worry about.

SARS made people very sick very fast so it was easy to identify and quarantine patients. With extensive contact tracking it was able to be contained.

With covid19 many patients are able to continue their lives and infect others without being obviously sick themselves. This limited the ability to contain outbreaks without extensive testing.

So, silly question: why the basic reproduction number R0 doesn't take this into account?

A lot depends on whether you mean:

* R0 when the disease appears first time and people dont know about it

* R0 when people learned about disease and changed behavior.

Assuming disease is new, one person sick with SARS will infect more people then one person sick with COVID.

Due to stronger symptoms and shorter time to symptoms, we learn SARS is issue, change our behavior and quickly close small area. SARS will spread less. In covid, by the time we figure area is infected, a lot of people are infected elsewhere. It takes us more time to react.

R0 is what it is, but I agree, it seems like there should be a more meaningful measure that takes factors like incubation period into account.

Doesn't that mean the effective R0 value for COVID-19 should be higher then?

It’s the same as how you win in Plague Inc — you want a virus that isn’t very lethal, has a long incubation period, and causes mild symptoms in most people.

That gives your virus time and opportunity to spread.

Fast lethality means the host dies before you spread. Strong symptoms means the host stays home and you don’t spread.

Covid19 hit the sweet spot. Asymptomatic for many days, barely noticeable symptoms in 70%+ of the population, then suddenly very deadly in the few percent that get bad enough.

More deadly viruses tend to kill its victim faster, before disease can be transmitted. Also, despite being Novel, COVID-19 could be mistaken for flu or be invisible, so could go undetected for longer periods. Countries grew fatigue from the scares of earlier epidemics like swine flu and avian flu, so waited until danger was "evidently on their doorstep".

With better testing, this could've been nipped in the bud worldwide. Also, with proper pandemic preparations and alertness, countries wouldn't need to shut down. Shutting down proactive measures to save small amounts of money, costs much, much more in the longer run.

You will witness every decent country hit by unconstrained exponential contagion, shutting down.

When it's too late, or people can't be bothered, they become Italy, Spain and Worse.

The simplest explanation is that describing a disease as more or less fatal (in this context) only answers the question, “if you already have the disease how likely is it to kill you?”

The total number of fatalities caused by a disease on the other hand depends on the spread across the population which is influenced both by the communicability and by the effect of the symptoms on its spread—how long are people infected, how long do the infected live, how identifiable are the infected.

Less fatal per case, killing more because wider spread.

The significant reduction in emissions worldwide is an opportunity to gather some interesting data that would have been difficult to estimate at other times. What other interesting science could be done now that might bring some positive from the pandemic?

A tangent from science towards ethics, but if we’re lucky, this pandemic will finally be the level of impetus needed to end the trade of live exotic animals for consumption. Thousands of species spared to save our own.

As a group of scientists wrote in 2007 [1]:

“The presence of a large reservoir of SARS-CoV-like viruses in horseshoe bats, together with the culture of eating exotic mammals in southern China, is a time bomb. The possibility of the reemergence of SARS and other novel viruses from animals or laboratories and therefore the need for preparedness should not be ignored”

[1]: https://cmr.asm.org/content/cmr/20/4/660.full.pdf

How does exterminating bats as vermin instead of cultivating and eating them spare them?

I don’t get your point. Just don’t exterminate them from their natural habitat?

Men's average sperm-count levels go down about 3% a year, and have been consistently for over 30 years. No cause is known, but pollutants are the best hypothesis.

I'd love to know if we see any sort of "rebound" in the quarantine period.

I’m doing research on mobility, and the pandemic is screwing up my data.

I would like a bit more clarity on this chart [1] comparing R_0 and case fatality rate of COVID-19 with other similar diseases. I am trying to understand why Ebola did not kill as many people as COVID-19 has.

My understanding is that R_0 just depends somehow only on the virus itself, while there is another factor R = a R_0, which determines the actual reproduction number "in practice", taking into account isolation measures and such. So for Ebola R was much lower than R_0, so a lot fewer people died compared to COVID-19. Is this correct?

[1] https://media.nature.com/lw800/magazine-assets/d41586-020-00...

I think Ebola killed people too fast, so it didn't have time to spread as far.

I get that, I am trying to understand the math and model behind this.

Let me clarify the paradox: Say Ebola has a R_0=4. That means one person infects 4 people under some circumstances. It doesn't matter if Ebola kills someone in 3 weeks or in 5 seconds, under some circumstances one person must be infecting 4. What are those circumstances, and how are they different from the actual circumstances which led to the Ebola epidemic stopping.

Those circumstances are that we dont know Ebola is spreading. Actual circumstances are quarantine, disinfection and other intentional measures to stop the spread.

Diseases that kill people fast are also much easier to track. They become very obvious and the short incubation period means that it is easier to track the contacts of people who were exposed to the victim.

Looking at the timeline. From what I have read, it seems like human to human transmission could have been confirmed much sooner.

"could have" with the benefit of hindsight and ignoring communication latency. The fact is authorities don't treat every local outbreak of illness as a contagious pandemic when it's almost always food poisoning.

In some places food poisoning gets a surprisingly thorough response, with full batch tracing of the affected food. Here's what the CDC was doing last year: https://www.cdc.gov/ecoli/2018/o157h7-11-18/index.html

Food poisoning that results in more that one case almost always gets taken very very seriously. At least in the US.

The R0 number they tout isn't supported by data from Italy or NY. R0 is density dependent.

R0 is not a biological constant for a pathogen as it is also affected by other factors such as environmental conditions and the behaviour of the infected population.

R0 being different in different places is expected. It's especially expected to change as measures are taken to control spread. Even in the absence of such measures, different cultures, even at the same population density, will often have different R0.

On that coronavirus timeline it would be good to see:

* Wuhan throw a party to celebrate the lunar year

* Almost the entirety of China goes on holiday for the lunar year

* New Year holiday

* Border lock downs of various Countries within that timeline

Does anyone have a good source for spanish flu CFR? I found many estimates ranging from 2%-10%...

I would be VERY interested to see these charts updated, as this data is a week old.

Such a clickbaity title.

Those charts don't look that powerful to me.

Why do people plot exponential curves on a non-logarithmic scale?

I think to non-scientists, or at least people who don't work with log scales, the use of linear scales makes the graph easier to understand. While I wouldn't expect to see this in Nature, this article reads like it is intended for a general audience.

Easier to misunderstand, yes. If the motivation is to simplify, they should plot 2 graphs, with a second graph being log plot or a zoom on the low scale part to show its not linear

A linear scale for that graph is completely appropriate: it’s showing how one data series has flattened out and the other continues to grow at an increasing rate. I would also argue that since one of those data series is clearly not exponential (it’s more of a sideways S-shape) it would be harder to interpret what that series actually looked like on a log scale.

If you choose to plot things on a logarithmic scale, you open a whole can of worms with expecting your target audience to be educated numerically and understand the implications of a line on a log-scale (which looks far less dire than an exponential on a linear scale).

Because you need to get the attention of (1) the man in the street, and (2) politicians. And if the politicians aren't taking notice, they will get a quick wake-up call from their electorate.

Australian news outlet uses a log plot. It certainly has a benefit, as you can clearly compare different countries. Is your growth rate more like Italy's, or more like Japan's? We, in Australia, certainly need to do better.


If you understand exponentials log plots are the way to go. But most people need a lesson in what they mean before nature gives them a catastrophic one.

It’s reasonable if there is a logistical curve on the same diagram.

because log charts are for quitters https://xkcd.com/1162/

I more worry about China get away with it. It have started SARS and now this. Both by eating wild animal. I do not believe it is biological weapon but more an accidental leak of virus during their research. But it is not that part that is lethal. But the part that there are so many wild animal market those virus can go and spread in stage 1. Then stage 2 punish everyone who said it and let it spread. The saying that it is not known is NOT true in China. The news were spread by doctors among themselves first in WuHan case and in SARS case one doctor bring it to HK and kill 300. And whilst the guy dare to say were punished, the systems (like wild market and no freedom of speech) continue. These two factors should be remember! Otherwise we will end up like twitter. They can use it to spread news (like American release the virus) even though they cannot even use twitter in China. If we forget and let them run WHO and PR war, ... good luck humanity.

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