How big will the coronavirus epidemic be? An epidemiologist updates his concerns
Category: Health, Science & Technology
Via: dignitatem-societatis • 4 years ago • 72 commentsBy: Maciej F. Boni
S E E D E D C O N T E N T
How big will the coronavirus epidemic be? An epidemiologist updates his concerns
The Harvard historian Jill Lepore recounted recently in The New Yorker magazine that when democracies sink into crisis , the question “where are we going?” leaps to everyone’s mind, as if we were waiting for a weather forecast to tell us how healthy our democracy was going to be tomorrow. Quoting Italian philosopher Benedetto Croce , Lepore writes that “political problems are not external forces beyond our control; they are forces within our control. We need solely to make up our own minds and to act.”
And so it is with the coronavirus epidemic. How big will this epidemic be? How many people will it infect? How many Americans will die? The answers to these questions are not written in stone. They are partially within our control, assuming we are willing to take the responsibility to act with commitment, urgency and solidarity.
I am an epidemiologist with eight years of field experience, including time on the front lines of the isolation and quarantine efforts during the 2009 swine flu pandemic. One month ago, I was under the impression that the death reports due to COVID-19 circulation in China were giving us an unfair picture of its mortality rate. I wrote a piece saying that the death rate of an emerging disease always looks bad in the early stages of an outbreak, but is likely to drop once better data become available. After waiting for eight weeks, I am now worried that these new data – data indicating that the virus has a low fatality rate – may not arrive.
Case fatality rate and infection fatality rate
By Jan. 31 2020, China had reported a total of 11,821 cases of COVID-19 and 259 deaths; that’s about a 2% case fatality rate. Two weeks later , the tally had risen to more than 50,000 cases and 1,524 deaths, corresponding to about 3% case fatality (the rise in the case fatality is expected as deaths always get counted later than cases). For an easily transmissible disease, a 2% or 3% fatality rate is extremely dangerous.
However, case fatality rates are computed using the officially reported numbers of 11,821 cases or 50,000 cases, which only include individuals who (a) experience symptoms; (b) decide that their symptoms are bad enough to merit a hospital visit; and (c) choose a hospital or clinic that is able to test and report cases of coronavirus.
Surely, there must have been hundreds of thousands cases, maybe a million cases, that had simply gone uncounted.
First, some definitions from Steven Riley at Imperial College. The infection fatality rate (IFR) gives the probability of dying for an infected person. The case fatality rate (CFR) gives the probability of dying for an infected person who is sick enough to report to a hospital or clinic. CFR is larger than IFR, because individuals who report to hospitals are typically more severely ill.
If China’s mid-February statistic of 1,524 deaths had occurred from 1 million infections of COVID-19 (counting all symptomatic and asymptomatic infections), this would mean that the virus had an infection fatality rate of 0.15%, about three times higher than seasonal influenza virus; this is a concern but not a crisis.
The IFR is much more difficult to estimate than the CFR. The reason is that it is hard to count people who are mildly ill or who show no symptoms at all. If you are able to count and test everybody – for example, on a cruise ship , or in a small community – then you may be able to paint a picture of what fraction of infections are asymptomatic, mild, symptomatic and severe.
Scientists working at the London School of Hygiene and Tropical Medicine , Imperial College London and the Institute for Disease Modeling have used these approaches to estimate the infection fatality rate. Currently, these estimates range from 0.5% to 0.94% indicating that COVID-19 is about 10 to 20 times as deadly as seasonal influenza. Evidence coming in from genomics and large-scale testing of fevers is consistent with these conclusions. The only potentially good news is that the epidemic in Korea may ultimately show a lower CFR than the epidemic in China.
Impact of the epidemic in the US
Now that new COVID-19 cases are being detected in the U.S. every day, it is too late to stop the initial wave of infections. The epidemic is likely to spread across the U.S. The virus appears to be about as contagious as influenza . But this comparison is difficult to make since we have no immunity to the new coronavirus.
On balance, it is reasonable to guess that COVID-19 will infect as many Americans over the next year as influenza does in a typical winter – somewhere between 25 million and 115 million. Maybe a bit more if the virus turns out to be more contagious than we thought. Maybe a bit less if we put restrictions in place that minimize our travel and our social and professional contacts.
The bad news is, of course, that these infection numbers translate to 350,000 to 660,000 people dying in the U.S., with an uncertainty range that goes from 50,000 deaths to 5 million deaths. The good news is that this is not a weather forecast. The size of the epidemic, i.e., the total number of infections, is something we can reduce if we decrease our contact patterns and improve our hygiene. If the total number of infections decreases, the total number of deaths will also decrease.
What science cannot tell us right now is exactly which measures will be most effective at slowing down the epidemic and reducing its impact. If I stop shaking hands, will that cut my probability of infection by a half? A third? Nobody knows. If I work from home two days a week, will this reduce my probability of infection by 40%? Maybe. But we don’t even know the answer to that.
What we should prepare for now is reducing our exposures – i.e., our chances of coming into contact with infected people or infected surfaces – any way that we can. For some people this will mean staying home more. For others it will mean adopting more stringent hygiene practices. An extreme version of this exposure reduction – including mandatory quarantine, rapid diagnosis and isolation, and closing of workplaces and schools – seems to have worked in Hubei province in China, where the epidemic spread appears to have slowed down.
For now, Americans need to prepare themselves that the next 12 months are going to look very different. Vacations may have to be canceled. Social interactions will look different. And risk management is something we’re going to have to think about every morning when we wake up. The coronavirus epidemic is not going to extinguish itself. It is not in another country. It is not just the cold and flu. And it is not going away.
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This is getting more concerning every day.
People are attempting already to process this sickness to the status quo of a generic flu. it is not the flu. But, what does it mean that there is no immunity for it? How are we immune to the flu? So many questions!
It's like a flu on steroids and it gives an infected individual flu-like symptoms.
That's self explanatory: Since this is a new strain of Corona virus, no one has been exposed to develop an immunity. Neither is there a vaccine.
We either receive a vaccine to protect us against the flu or we get infected by the flu and our immune systems develop an immune response to make us immune to the infectious strain of flu.
I know I'm going to get jumped for this but here goes.
We get a virus almost every election cycle.
2004 - SARS
2008 - Avian
2010 - Swine
2012 - Mers
2014 - Ebola
2016 - Zika
2018 - Ebola
2020 - Corona
Just another election year with mass hysteria.
My son noticed that also. I am all for prevention and being careful, but I am also wary of people out there ring bells & crying "the end is coming".
I just keep flashing to Stephen King's The Stand. Man made illness that they lost control of.
Yeah, and I keep on hearing, loudly, "THE SKY IS FALLING".
Those are the voices you have to take with a grain of salt. In my way of thinking - que sera, sera. I take each day as if it were my last, because you never know.
The timing just strikes me as odd.
And you're right. The Stand does come to mind.
Except this wasn't manmade and didn't escape from a lab. It was spread from wild animals at a market - as these things so often are. If I recall correctly, Ebola jumped from monkeys to humans through the practice of eating bush meat.
A thought: Is it possible these people are ingesting bush animal's blood?!
I was thinking of the Stand more in the way the panic began & the "end is nigh" people came out of the woodwork just like with this.
I did not know they discovered where it came from... I could see it being man made - need to thin the herd, dontcha know....
I think pangolins are another possible source. I don't know whether it was just handling the animals that spread it, or not.
Fun Fact:
Stephen King first dreamed up the superflu known as “Captain Trips” in the 1969 science fiction short story “Night Surf,” which was published in the University of Maine’s Ubris literary journal. In this early iteration, the virus apparently originates in Southeast Asia.
I read that. It was spooky to me.
A friend sent me a tweet where King is saying this is nothing like the Stand because this is "eminently survivable". Someone tweeted back "and how the hell would you know?! Did you even read the book?"
I have someone close to my family that just fell off the wagon because he is panicking over this & he ended up with alcohol poisoning. It is crazy to me.
I didn't know that and I am a big Stephen King fan. Cool fun fact.
But actually, for those of you who are old enough, long before Stephen King wrote that the movie "The Omega Man" had the Chinese coming up with an unstoppable germ warfare, that almost ended the world.
It's worth the watch even if it's a little dated.
Very spooky. Lol, about the tweet.
Andromeda Strain....
Movie good.... Book great! As applicable today as it was when Michael Crichton first wrote it back in 1968
True! I forgot about that book and movie. Bad Perrie! Michael Crichton was from my hometown of Roslyn.
I read that a specific animal in China carries it. I don't remember the name of the beastie, but it looks kind of like a cross between an armadillo and a hairless anteater.
I like the remake of that movie with Will Smith.
That is the pangolin
Night surf still gives me the shivers
Ohhh, do you think that Canada and the US are helping China keep their secret?
The way I came up with it goose is that the US and the Canadians are working with the virus. I'm pretty fucking sure that US and Canadian scientist would be able to suss out the virus' RNA would sound the alarm if the virus was a product of a Chinese lab.
Papers are already being posted on COVID-19 in science publications, they know a lot about it already.
Try to keep up...
Actually, I DO have an idea. How about you post some support for your conspiracy theory? What evidence do you have that the virus is man made and escaped from a Chinese lab.
Just an odd coincidence. And MERS was highly deadly killing at 34% and really didn't affect us at all as did Ebola. Zika is from mosquitos and their whole purpose on earth is as a vector to kill people (aka population control).
Mosquito-borne diseases - WHO | World Health Organization
We owe our independence from Britain every bit as much to the mosquito as we do to the Continental Army!
You know you are quite right about that. Most people don't know that little fun fact. Thanks for bringing it up.
For more reading on this:
Perfect!
Mosquito borne diseases scare me more than the coronavirus
A little trivia: the mosquito as a disease vector helped thwart the US invasion of Canada, in the War of 1812 if I recall correcly.
Until the advent of modern medicine it was expected more troops would die of disease than combat during long military campaigns...
Back in those days, a wound might as well been a death sentence.
I was thinking about that and realized it shouldn't be so surprising. We hold federal elections every other year, and outbreaks that could threaten us happen pretty much all of the time around the world. Considering that the threats can last for years, of course they'll overlap with election cycles.
Here's a list of 21st century epidemics (scroll up for earlier ones if you want). SARS was a concern from 2002 to 2004. MERS has been a concern since 2012 and still is. Both are coronaviruses. Ebola has popped up several times since 2004. Flu is always there. If it seems like a bigger deal than it used to be, it's probably because the world is a smaller, more interconnected place today, with more potential for diseases to spread rapidly.
Most of those outbreaks didn't end up affecting us much at all, but COVID-19 will. It went worldwide in practically no time at all, and according to the numbers in this article, we're talking about a minimum of 50,000 deaths in the US alone. And that's just the low margin of error estimate, with the main estimate being 350,000 to 660,000 over the next year.
The numbers aren't set in stone, of course, but it's probably time to take this outbreak a little more seriously than some of the previous ones. The fact that it's an election year should be irrelevant. It's not a conspiracy.
The economic impact of this is so much greater. Look at the black plague. Ships introduced so many diseases back in the day. Now we can hop on a plane, no fleas required, and spread something we don't even know we have.
A pandemic afflicts “all peoples”, and so is what epidemiologists define as “an epidemic occurring worldwide, or over a very wide area, crossing international boundaries and usually affecting a large number of people”. The World Health Organization adds that, in a pandemic proper, “almost simultaneous transmission takes place worldwide”.
An epidemic is something visited “on the people”: a sickness such as influenza, or the plague, that spreads among a population at a particular time.
We should be using the term pandemic vice epidemic.
Oh yeah - the good news is that all of the 10 people tested IN THE ENTIRE STATE of NM had negative results. Yup - I'm encouraged by those findings.
As a pre qualifier..... I'm 60 years of age, and in good health.
I'm probably going to get beat up/jumped on for this concept...…(pin pulled... grenade tossed)
What if we let this thing run its course? I'm not suggesting it, I just want a clear understanding of all aspects, even those I may not be seeing. I'm not a heartless bastard, just the opposite.!
It is very much a truism... "What doesn't kill you makes you stronger." As this is a new virus, would humanity be better off having their immune systems generate a heightened ability to fight this and similar strains of virus in the future? Would we not be making the species stronger?
By "ripping the band aid off", do we get through this faster and stronger once we come out the other side?
Are we going to "overload" our systems with too many deaths, or are we going to unload much of our needed medical/social programs?
Ma nature will cull out our species like it does for all species.... It is inevitable and unpleasant, but a simple law of nature. We live on an isolated rock of finite resources, and our continued population growth is unsustainable. If not this virus, then what about the next one?
Okay... I served it up! Time for all of you to chow down on these comments.
Fly
Hate to say it but we are probably at that point already. I don't see any way to contain it. Just lessen the spread, so to speak.
I have to agree. What is going to be painful for us to endure is what happens if this virus gets into assisted living facilities and homes for the elderly.
We already know it can be deadly for those with compromised immune systems.
I have to agree, too. But then again, as long as it's not someone I care about, LOL!
It has already hit assisted living facility's in WA and CA with 4 deaths. I am 67 and don't know how CV would affect me. But I have survived typhoid fever and 5 episodes of pneumonia, one of which was avian so I think I have a pretty good immune system (fingers crossed).
Because lots of old people and sick people will die, but you obviously know that. The mortality rate in those people is very high. It's interesting that it barely affects children, though. That may lead to some breakthroughs as scientists try to figure out why that is. Is it because their lungs haven't had exposure to as much damage as older people? Is there some other reason that might indicate a cure? Who knows?
I was looking up stuff about efforts to contain Spanish Influenza. The only appreciable effect is to possibly delay the virus in much of the population, so it doesn't overwhelm our health care system. Or, in the case of one country during the Spanish Flu, it delayed the virus long enough that it was less virulent when it got there (I think the Spanish flu, like the "regular" flu, doesn't do nearly as well in warmer weather. But that doesn't seem to be the case here since many of the countries where it is prevalent are warm right now).
But really - yeah,I think it's likely that the majority of us will get this. And since it's a coronavirus, I don't think our immune systems will necessary generate a heightened sense in the long term. I think that for coronaviruses such as the common cold, the immunity you get from having that particular cold only lasts for 2 or 3 years.
I think that for coronaviruses such as the common cold, the immunity you get from having that particular cold only lasts for 2 or 3 years.
That's the kind of information I'm looking for!
As far as mutations go, normally bacteria and viruses become less virulent as they mutate. It is simply that those that kill their hosts, manage to kill themselves. In nature, there are always exceptions .
I was thinking about that. Wondering if the fact that children haven't taken the amount of antibiotics that adults have over time may have an effect.
".....amount of antibiotics...."
Very doubtful. The immune system is much like a muscle. The more it is used, the stronger it is. The immune systems in the young is underdeveloped, but still able to generate a response. Compromised systems like those in seniors from chemotherapy, or those whom are on medications to retard the response of their immune systems are subject to critical infections.
I haven't found anything yet which explains why the Spanish flu affected primarily young, healthy males. Not the young or the old. The crowded conditions for all the young healthy males in WWI doesn't seem to explain it
It doesn't sound that way to me, because this is a coronavirus. antibiotics don't work on viral diseases like the common cold if I understand it correctly
I read somewhere, and I can't remember where, that it was the immune system's reaction to the Spanish flu that was the problem. Many cold and flu symptoms are our immune systems' attempts to kill or expel the virus - fever, mucus production, vomiting and diarrhea. An immune reaction that is too robust can actually cause more harm than good, and young, healthy young men have robust immune reactions, generally speaking. In the case of the Spanish flu, their own immune systems may have been their downfall.
Childrens' immature immune systems not reacting to the virus may be keeping them safe from coronavirus.
There seems to be (at this time) a correlation in the mortality rate and diabetes. Researchers haven't quite figured out why yet. I'm close enough to 54 and have type 2. I wouldn't give myself odds to survive.
Nah. Don't think like that. Just be extra careful.
One thing we can all do is make sure we take care with touching what you might call 'public surfaces' like door handles in public places, shopping cart handles, etc. When you go out for shopping or anything else, make sure you don't touch your face with your hands until you've gotten home and washed them thoroughly.
I'm positive I caught the flu from a shopping cart once. It was so bad it made me wonder if I'd ever really had the flu before. Every time I've used a cart since, I imagine some sick person wiping their nose with their hand or coughing into it and then putting it right back on the handle just before I got there. Now I use those sanitary wipes on cart handles at every store I go into, which might be another thing we should all be doing during this outbreak.
We are wiping those surfaces down here at our office too. We've had a horrible flu season.
hat if we let this thing run its course
The danger from the virus and a rapid increase in victims is the stress it puts on the medical system as a whole. Even the "mild" cases of this are serious and close to 20% require venitlation. What happens when the vrius runs rampant is everyone gets sick at the same time and medical care for everyone collapses, not just those with coronavirus. It's what's going on in northern Italy rigth now and is what happened in Wuhan last month. The death rate from the disease itself is much higher in Lombardy and Wuhan because the system simply cannot cope.
Public helath officals are trying to flatten the curve of the disease so the medical system can keep up.
This is from a doctor on the ground in Italy and his story of what happens when the infection spikes:
Here's another one that I think puts into perspective the challange this creates:
Thanks much...… Again, that is information I need to evolve my thoughts.
Flatten the curve.
Great info.
Exactly. Also imagine a city fire department unable to adequately respond to 5 alarm fire because most of them are to sick to work. It would only take one small city for that to make an impact.
Well since the vast majority of 60+ women won't be 'contributing' to the species, I guess it's the 60+ men we can 'afford' to cull for the benefit of strengthening the species.
BTW, you just whipped out me, my wife and my mom and my in laws [who both live in an assisted living facility].
I guess we all wasted our time getting flu shots this year.../s
A bit on history on the Spanish Flu in the US. It was extremely deadly to Native peoples (Native Americans). In Alaska, whole villages were wiped out.
My grandmother and her baby daughter (one week old) died from it in Northern MN. My grandfather told me that so many people died that they could not bury them fast enough. Many bodies were stored in ice houses. (blocks of ice surrounded by sawdust in a building) until they could be buried.
He vividly remembered it and how it devasted his life and our community.
Sadly it was only one of two events that were devasting to many of us (Native Americans) and the people of MN.
It was that year, 1918, that one of the deadliest wildfires in history struck. Whole towns were obliviated and well over 400 people died that they know of. Many experts feel that the number is very low.
And if I remember my readings...… Native Americans, having not being exposed to the many European plagues and viral outbreaks prior to colonization starting in the 15th century, they had not developed the stronger immune responses to later strains like the Spanish Flu.
For the record, the largest proportion of those that die from the flu is due to dehydration. Like many less virulent viral infections, if you can fight the symptoms of fever, and dehydration, you can beat the infection.
My ancestors encountered a decimated Native American population before they even settled in New England; estimates are that as many of 90% of the indigenous people in the northeast were dead by then. Disease spread from the earliest encounters .. and not always with further European contact in between Columbus to the interior of North America.
I've read before that that's why the Pilgrims were able to settle at Plymouth without much resistance. The Wampanoag who previously lived there (leaving behind clearings and worked soil that the Pilgrims took advantage of) had almost been wiped out by some pathogen introduced just a few years earlier by European fisherman somewhere up around Maine, which then went down the coast like wildfire.
Just found this article about it, which attributes the epidemic to a disease called leptospirosis.
The Pilgrims Should Have Been Thankful for a Spirochete
A gruesome disease granted them uninhabited, cleared land and a sweet brook.
This is one of the things I read about it:
Yup. That was across the bay, though, out on the Cape.
Okay, that part made me roll my eyes a little. That article seems to have a healthy dose of pro-Pilgrim bias, almost in an apologist sort of way. Making a crossing poorly prepared for settlement and suffering the deaths of fully half of their complement in the first year isn't exactly what I'd describe as "remarkable toughness in their survival on the beach", and they repaid the Nausets more to lessen tensions and avoid attack than anything else.
I have a copy of William Bradford's book 'Of Plymouth Plantation' around here somewhere, which also includes all of their journals for the first year at Plymouth. Suddenly I'm in the mood to read through it again.
Yep, pretty sappy. But until I read that I didn't know that one of the first things the Pilgrims did was steal from the Natives. Oh and exactly how does one 'pay' for stealing a peoples future crop, as that was their 'seed corn'.
Yeah, their crossing was a bit of a disaster. There were supposed to be two ships, but one proved unseaworthy so they overcrowded the Mayflower with people from the other boat. The trip itself took longer than it should have because of the winds that time of year (I think), and when they finally got to the New World they were in the wrong place and had to find somewhere new to land in a hurry as they were pretty much out of provisions. That's how they ended up scouting Cape Cod, which is where they found the Nausets' corn. By that time they were nearly starving, so it's understandable that they would take it out of desperation.
I forgot that another reason they repaid the Nausets for that corn was to get a boy back who had gone missing and had either been found or captured by them. So, not really an honorable recompense for stealing from them at all.
I don't know if I ever read what they gave to the Nausets in return, but it was the first summer so I wouldn't think it was corn as they hadn't really had enough time to grow their own surplus of it. Resources were still pretty scarce.
This conversation has reminded me that this year is the big 400th anniversary of Plymouth. 1620-2020. Probably going to be lots of activities and celebrations at Plimoth Plantation . I think the replica ship Mayflower II is supposed to go there for the anniversary and then stay there permanently. If anyone ever wanted to go and see that place, this would be the year to do it. If the coronavirus doesn't shut it down, that is.
"How big will the coronavirus epidemic be?"
As big as it will get. That's the ONLY "Given" we can be sure about !