In a rare piece of good news about Covid-19, a team of infectious disease experts calculates that the fatality rate in people who have symptoms of the disease caused by the new coronavirus is about 1.4%. Although that estimate applies specifically to Wuhan, the Chinese city where the outbreak began, and is based on data from there, it offers a guide to the rest of the world, where many countries might see even lower death rates.

The new figure is significantly below earlier estimates of 2% or 3% and well below the death rate for China based on simply dividing deaths by cases, which yields almost 4%. While it is still higher than the average 0.1% death rate from seasonal flu, it raises hopes that the worst consequence of the coronavirus will be uncommon.

Cutting against that optimism is the expectation that, because no one was immune to the new virus, “the majority of the population will be infected” absent the quick arrival of a vaccine or drastic public health interventions such as closing public places and canceling public events, the scientists conclude in a paper submitted to a journal but not yet peer-reviewed.

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The expectation that a “majority” of a population will become infected reflects a worst-case scenario about who encounters whom, something modelers call “homogeneous mixing.” But even the more realistic assumption that not everyone mixes with everyone else means that “at least a quarter to a half of the population will very likely become infected” absent social distancing measures or a vaccine, conclude Joseph Wu and Kathy Leung of the University of Hong Kong, leaders in the modeling of infectious diseases, and their colleagues.

The Covid-19 pandemic is sparking efforts to calculate how deadly this new disease is. One measure is called a case fatality rate. While the formula is simple, it’s difficult to get a precise answer.

The better news involves fatality rates. To calculate those, the researchers used data from Wuhan, especially the age distribution of 425 early cases and 41 early fatalities there.

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The chance of someone with symptomatic Covid-19 dying varied by age, confirming other studies. For those aged 15 to 44, the fatality rate was 0.5%, though it might have been as low as 0.1% or as high as 1.3%. For people 45 to 64, the fatality rate was also 0.5%, with a possible low of 0.2% and a possible high of 1.1%. For those over 64, it was 2.7%, with a low and high estimate of 1.5% and 4.7%.

The chance of serious illness from coronavirus infection in younger people was so low, the scientists estimate a fatality rate of zero.

As physicians and researchers have seen since the start of the outbreak, many infected people never become sick. As few as 14% of people in Wuhan with early coronavirus infections were being detected, said epidemiologist Jeffrey Shaman of the Mailman School of Public Health at Columbia University, who led a study published on Monday in Science on undocumented coronavirus infections.

“I think there are many more than the [nearly] 70,000” confirmed Covid-19 cases in Hubei province, Shaman told reporters.

That means the “infection fatality rate” — deaths among people who have the virus but might or might not show disease symptoms — is even lower than Wu and his colleagues calculate.

Despite Wuhan’s heroic efforts to treat patients, the suddenness of the epidemic overwhelmed hospitals there, much as it has in northern Italy. In countries that got more advance warning and prepared better, especially if social distancing succeeds in “flattening the curve” enough to dampen what would otherwise be a tidal wave of Covid-19 cases, the death rate is likely to be lower still.

“Fatality risk estimates may not generalize to those outside of [Wuhan], especially during subsequent phases of the epidemic,” Wu and his colleagues write. “The increasing availability of newer, and potentially better, treatment modalities to more patients would presumably lead to fewer deaths.” That’s true even within China, they find: “To date, the death-to-case ratio in Wuhan has been consistently much higher than that among all the other mainland Chinese cities.”

Lest anyone be tempted to downplay the threat, the scientists caution that Covid-19 is on track to infect millions of people. If social distancing fails to dampen the number of cases at any one time, overwhelming health care systems, the death rate would be higher.

  • So basically, what many of of you are trying to saying is that the WHO and almost every other country in the world has got it wrong. That every country that has “shut down”, that have put their economy at a stand still or in recession, that have put thousands of people’s live on hold and jobs and future at risk have done so because of mass hysteria?

    I think time you ask yourselves what makes more sense?? Obviously, if you are more worried about the economy than with lives, then forget I asked the question.

  • This article is arguing that the mortality is likely to be much lower than the expected 3.5% but citing a study of 425 patients where 41, or nearly 10%, died. That’s a bit odd.

  • So the death rate of the seasonal flu is 0.1% without severe quarantine measures. The death rate of the Corona in Italy at the moment is around 8-9% and rising with complete shutdown of the whole country in order to make it easier on their health care system. It’s true that most Corona cases are undetected, but the same applies for the seasonal flu too, so we can scratch that argument off. I’ve read some reports that this virus is 2-3 times more contageous, but honestly, this looks like a severe underestimation. It’s spreading like wildfire and it’s so much deadlier that the only way to stop it is to lock everyone in their homes. Not to mention that this is only the beginning. The comparison with the seasonal flu is absolutely ridiculous. The numbers alone clearly show that the Corona is HUNDREDS of times more dangerous. If you want to compare it with something the Spanish flu is a good candidate. It killed between 50 and 100 million people. It affected 1/3 of the world’s population, while experts say that the Corona would probably affect 2/3. Back then health care was in a different realm altogether, but so was the movement of people across the globe and within communities. The genie is already out of the bottle and the whole world is lit up. Even with today’s advanced medicine, without lockdowns the death toll may even surpass the Spanish flu because the population is much denser and much more interconnected. The health care systems would be able to provide help to only a minor part of the infected and the death rate would skyrocket. Are you really ready to lose 100 million people or more? Don’t forget that these people support the business you care so much about. And while lockdowns are temporary, when people die, they die forever. You’d lose years and decades worth of potential income from those who perished. Not to mention that if we all go out there and continue doing our business as usual very soon a large number of us will be sick and unable to work anyway. All at the same time. Temporary lockdowns are not only necessary, they are inevitable. If we don’t impose them on ourselves the virus will impose them on us anyway. The only difference is that if we it on our own will we will save millions of lives. It’s actually an easy choice to make. If it wasn’t the most powerful countries in the world would never go there. Some hesitated for a moment only to realize that there really is no other option. Look at the Italians now. They wish they went into a lockdown a month ago.

  • It’s nice to see there are some other logical people here that can understand the outcome of the actions we are taking around the world and what the (I’ll be pessimistic as possible here) 90% of people remaining will have left when were done. This game were playing is far more dangerous than the virus. We would go to war for our way of life, but now want to throw it away for fear. We’ve become a weak and pathetic species it seems, although thankfully there are exceptions. There are logical ways to handle this virus at far less a cost to humanity, but that is being ignored by way of Chicken Little Syndrome.

    • Yes! Whatever happened to “the land of the free and the home of the brave”? What we are doing to ourselves is a cure more deadly than the disease. There is nothing left but to go home, suck our thumbs and take a cyanide pill, our weak little heads pillowed on toilet paper.

  • Here is another stat from CDC. Each year in America approximately 2 million people over the age of 65 die of all causes.
    I think it’s important to factor in here that some of the causes are being shifted to Coronavirus. So so the number of deaths are inflated for Coronavirus when those deaths would have would have happened anyway for other causes.

    now this is morbid here but let’s just say two million people died in the United States above the age of 65 this year from Coronavirus. what is the difference between them dying from all the other things vs coronavirus?

    What if 3 years worth of 65 and older persons died in one year meaning six million people? I think we would see a dramatic fall in the number of deaths for the following two years because those deaths occurred early from coronavirus instead of the other underlying causes. This is very morbid, but based on actual numbers of people who are going to die in the next 3 ish years. I’m not proposing that they do die. I’m proposing to let everyone else live and let each individual decide their own risk tolerances. Nobody banned cheeseburgers and sedentary life. Some things can’t and should not be controlled. But cheeseburgers and sedentary life will kill approximately 750k Americans over 65 each year.

    Meanwhile, we are halting our economies and driving a hundred percent of financially challenged individuals onto the government dole. We are also causing Amazon and Walmart Home Depot other large-cap companies to grow dramatically while telling small business owners that have to shut down. It sure feels like an unintended market disruption to me.

    • It’s so fxxxed up Mike. I was totally in the hysteria yesterday. Now my eyes are open. They had a low winter death rate in Europe this year so there are a lot of very sick people that would normally have been dead by now just hanging on and the coronavirus is putting them out of their misery. And to stop this we’re destroying the world economy, smashing the life’s work of millions of people, destroying the dreams of millions of others. It’s so fxxxed up.

    • Here is another stat from the CDC

      The CDC reports that 20% of hospitalizations of the virus in the United States are between the ages of 20 and 44. 55% of the cases are younger than 65. The rest are 65 and older.

      So this idea of quarantining the elderly and let everyone else get infected is ridiculous.

      We need to flatten the curve.

      Those who are advocating for something else are either very ill-infomed or very selfish but not wise. It is going to affect you whether you get infected or not. The economy is going to close down no matter what.

      If cases double every four days this will have an impact. So it makes sense to flatten the curve.

      Here is an example of stupidity.

      Despite two weeks of the President, Vice President, Governor, and various state and federal health officials telling people to self-quarantine, Georgia State Senator Brandon Beach did not. He had a cough and fever last Saturday, got tested for COVID-19, then participated in a special session of the Georgia legislature on Monday. His test came back positive on Wednesday. He was both sick and contagious. The entire Georgia legislature is now being asked to self-quarantine. Ironically, they shut the place down last Saturday because the Governor feared something like this could happen. But the legislature had to come back to give Governor Kemp emergency powers.

    • I agree 100%. When it finally dawns on people that the so called experts were wrong about the grave threat of covid19/they won’t admit it. You will hear the phrase “better safe than sorry” but I am angry and my retirement has been cancelled due to sheer stupidity and unwarranted panic.

    • “The CDC reports that 20% of hospitalizations of the virus in the United States are between the ages of 20 and 44. 55% of the cases are younger than 65. The rest are 65 and older.

      So this idea of quarantining the elderly and let everyone else get infected is ridiculous.”

      That’s a straw man. First off, the idea is to quarantine the elderly AND everyone else considered high-risk. NOT just the elderly. Big difference. It should be a lot easier to quarantine 50 million people rather than 330 million people, and keeping the economy alive surely makes it easier to care for EVERYone, including the high-risk. But a cratered economy helps no one.

      Second, your CDC information is missing some very important contextual details: how many of those people were already suffering some OTHER medical issue that contributed to their need for hospitalization? Why won’t they say what portion of 20% were otherwise healthy?

      The point is, the unhealthy and the elderly – the demographic most at risk from Wuhan flu – are who should have been aggressively targeted for quarantine, and the rest of us – the other 250 million Americans – should have been enlisted to serve their needs until the Wuhan flu ran its course. We as a people should have been smart enough and creative enough to figure out the best way to do that. We as a people would have met that “call to arms”, that challenge, willingly and enthusiastically, AND, the economy wouldn’t’ve suffered.

    • I wrote something similar on one of the other stat articles. CDC data indicates that about 2.6 million people over the age of 45 died last year, or about 1.9% of all people 45+ years old, with a heavy weighting toward the oldest categories (13.5% for 85+ and 4.4% for 75-84). Around 40% of those 2.6 million people, or about 1.1 million, have a cause of death related to respiratory diseases or influenza and pneumonia (the cause of death is defined as “the disease or injury which initiated the train of events leading directly to death”, not necessarily what dealt the final blow – I’m not including cancer, which is probably conservative since that compromises the immune system). So basically anyone who has one of these diseases and then catches an infection that kills them is in that 1.1 million bucket. Which begs the question – how many of these Covid deaths are just filling up that 1.1 million bucket vs adding to it? Common sense would suggest that, unless Covid miraculously targets only those people who otherwise would not have died, we’re dealing with some serious overlap issues here. I know it’s hard for people to fathom this not being a big deal given the media blitz and measures being taken, but just consider for a second how much you heard about those 1.1 million deaths last year.

  • When you factor all the untested people who have corunavirus which is estimated at 5 to ten times the tested cases the death rate is the same or lower than the flu – so why are we destroying our economy???

    • You comment assumes that all the “untested people who have corunavirus” will live. That’s not a good assumption. The death rate is much higher than the flu.

    • It is inevitable you will know just about all the deaths caused by COVID19, whether or not they were tested before death. When COD is established, that will add to the figure. It’s the vast amount of cases that go untested that lowers the overall death rate. You only hear about the worst cases but ignore the ones with a positive outcome. I have a head cold.. maybe it’s COVID19. It more likely is the same type of sinus infection I’m prone to every year. I’m almost fully recovered. What if it was actually COVID19 and I just didn’t know? That wont count towards the overall number of cases. If I died, it would. We’re still in cold and flu season. This scenario is surely playing out with the many mild cases that present with this virus.

  • It’s difficult to know what the actual numbers are. In comparing the Johns Hopkins web site to the WHO and CDC, the numbers are vastly different. The positive cases and deaths are much higher on the Johns Hopkins site. I know it’s supposedly closer to “real-time,” but their numbers have been higher a day or two before the official numbers posted on WHO and CDC. This is frustrating because the numbers we see should be accurate and up-to-date, and consistent. This is one of the many reasons how misinformation spreads, often times unintentionally.

    Using the Johns Hopkins web site at 10:53am this morning (3/19/20), the death rate in the USA was 1.6% (150 fatalities with 9,415 total confirmed cases). Just two hours later (at 12:43pm), the death rate in the USA decreased to 1.4% (154 fatalities with 10,755 confirmed cases). I fully understand that some of the current “confirmed cases” could turn into fatalities. However, when we look at South Korea, which was hit much earlier on and where very extensive testing has been conducted, their mortality rate has hovered between 0.8 and 1.0%. In Germany, it’s currently under 0.3%, and in Switzerland, it’s under 0.1% with 3,888 cases and 36 deaths. Of course, in Italy, the death rate is much higher.

    Yes, those numbers can and will change over time. Death rates could go up as some confirmed cases tragically turn into deaths, but they could also go down as more and more people are tested. As we’ve seen, many people (especially the young/healthy) who are infected don’t even know it because symptoms can be incredibly mild.

    To summarize — Let’s keep a macro viewpoint where reason and logic dictate policy. And let’s restrict the spread as much as possible without collapsing the economy and surging unemployment.

  • The US numbers on deaths as of 3/19/2020 according to the CDC.
    9305 confirmed cases
    155 deaths
    1.67% cumulative mortality rate
    Stats, not opinions.

    • You can’t simply divide the deaths by total cases. You have to look at completed cases where the patient has either recovered or died. For completed cases in the US the death rate about 60% which is probably too high because the virus is just beginning here. For countries with longer experience than us, the death rate runs from 4% (probably low) to 42% in Italy and Spain which are probably more realistic.

    • The qualifier “confirmed” is what makes your “stats” mere factoids.

      Another stat is “number of people who, unbeknownst to us, had it or have it but we don’t know and will never know because they weren’t tested, won’t be tested, or don’t even know they have it”. Do you have that number? If you don’t, then you don’t know the “cumulative mortality rate.”

      In fact no one knows it. But it’s a real number, and it belongs in your denominator along with your 9,305. When added to your denominator, your “cumulative mortality rate” will plummet. Because we almost certainly know the number of deaths. So the correct numerator is very close. But the denominator is very likely very understated.

  • I am afraid that the population in china exceeds 900,000,000 people. They hid this disease for months. Who is to say they are accurately reporting death and/or infection rates. We are better off to get statistics from our allies in Europe, where this has spread to, than from China.

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