The World Health Organization says that 3.4% of reported COVID-19 patients worldwide have died – a global fatality figure that President Donald Trump dismissed as “a false number.” It’s not a false number, although experts say Trump has a point that the fatality rate may ultimately be quite a bit less than 3.4%.
Trump says the true rate is much lower because the WHO’s rate does not take into account unreported cases. The WHO rate comes from the actual number of known cases and fatalities.
The dispute began March 3 when the head of the WHO announced that the mortality rate for the new coronavirus was 3.4%, which was higher than previously believed and made it far more deadly than the seasonal flu.
“Globally, about 3.4% of reported COVID-19 (the disease spread by the virus) cases have died,” said WHO Director-General Tedros Adhanom Ghebreyesus at a briefing. “By comparison, seasonal flu generally kills far fewer than 1% of those infected.”
He said there had been 90,893 reported cases of COVID-19 globally, and 3,110 deaths.
Trump challenged that number. “Well, I think the 3.4% is really a false number,” Trump said in a telephone interview March 4 with Fox News’ Sean Hannity.
The problem, the president said, was that many people with mild cases of coronavirus simply weren’t being counted, resulting in a deceptively high figure for the percentage who have died.
Trump, March 4: Now, this is just my hunch, and — but based on a lot of conversations with a lot of people that do this, because a lot of people will have this, and it’s very mild. They will get better very rapidly. They don’t even see a doctor. They don’t even call a doctor. You never hear about those people. So, you can’t put them down in the category of the overall population in terms of this corona flu and — or virus. So you just can’t do that. So, if we have thousands or hundreds of thousands of people that get better just by, you know, sitting around and even going to work — some of them go to work, but they get better. And then, when you do have a death, like you have had in the state of Washington, like you had one in California — I believe you had one in New York — you know, all of a sudden, it seems like 3 or 4%, which is a very high number, as opposed to — as opposed to a fraction of 1%. But, again, they don’t — they don’t know about the easy cases, because the easy cases don’t go to the hospital. They don’t report to doctors or the hospital in many cases.
The actual mortality rate, Trump said, “is way under 1%.”
For comparison, SARS killed around 10% of infected people, if not more, while seasonal influenza typically kills 0.1% or less, David Fisman, an epidemiologist at the University of Toronto, told us in a January email.
A number of disease experts agree with Trump that there are many unreported cases and that the rate reported by the WHO is higher than the rate will end up being over time. It’s relatively easy to know how many people have died from the disease. But it takes a while to have a fuller sense of how many people have it, for the reason Trump cited — they have a mild case and haven’t sought treatment — or because they don’t even know they have it. And very little testing has been done. In other words, experts say, we have the numerator but not the denominator.
In time, and once much more testing has been carried out, the rate will fall, they say. But one WHO expert who visited China doesn’t think there are that many undiagnosed cases.
Vaccine expert Paul A. Offit told us the rate could go below 1% as Trump says. “I think Trump is right,” said Offit, who holds the Maurice R. Hilleman Chair of Vaccinology at the University of Pennsylvania.
Offit likens the situation to the swine flu epidemic of 2009. At one point, he said, the mortality rate was thought to be much higher than the 0.01 to 0.03% it turned out to be. He thinks the mortality rate for coronavirus will similarly plummet and the “false notion that it is more likely to kill you than influenza” will disappear.
Offit believes there has been a “wild overreaction” to the disease, in part because it is new. “We’re more the victim of fear than the virus,” he said.
Other experts agree that mortality rates at this point in an outbreak are wobbly since its full extent is not known. Fisman told us in January that statistics at the time might not tell the full story. He said it was likely far more people had been infected, but had not gone to hospitals or had their illnesses confirmed. At the same time, he pointed out that some of the people who are sick might die, pushing the rate in the other direction.
Gary Kobinger, director of the Infectious Disease Research Center at Laval University in Quebec, told the health website STAT in February that it would be highly unusual if there weren’t mild cases that had been missed. The website’s article said: “He pointed to the fact that outbreaks have popped up in countries far from China — including Iran and Italy — because people with mild infections were not detected and traveled to other places.
“There are mild cases that are undetected. This is why it’s spreading. Otherwise it would not be spreading because we would know where those cases are and they would be contained and that would be the end of it,” Kobinger told STAT.
But there is by no means unanimity on the subject. Bruce Aylward, a Canadian epidemiologist who led a WHO team to inspect China’s response to coronavirus, doesn’t believe there are nearly as many undiagnosed cases as other scientists do.
“There is no evidence that we’re seeing only the tip of a grand iceberg, with nine-tenths of it made up of hidden zombies shedding virus,” he told the New York Times. “What we’re seeing is a pyramid: most of it is aboveground.”
In Guangdong, he said, “they went back and retested 320,000 samples originally taken for influenza surveillance and other screening. Less than 0.5 percent came up positive, which is about the same number as the 1,500 known Covid cases in the province.” He concluded, “Once we can test antibodies in a bunch of people, maybe I’ll be saying, ‘Guess what? Those data didn’t tell us the story.’ But the data we have now don’t support it.”
A Feb. 28 editorial in the New England Journal of Medicine, co-authored by Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, took the position that the mortality rate may well fall dramatically. It said if one assumed that there were several times as many people who had the disease with minimal or no symptoms as the number of reported cases, the mortality rate may be considerably less than 1%. That would suggest “the overall clinical consequences of Covid-19 may ultimately be more akin to those of a severe seasonal influenza,” the editorial said.
After the WHO announced the 3.4% mortality rate, a number of medical experts asserted that the rate would shrink over time.
“When we see systems that are able to account for not only the really sick, but also those who have infection and are outpatients, the CFR [case fatality rate] is more accurate and drops considerably,” Isaac Bogoch, an infectious disease specialist at the University of Toronto, said in an interview with the website Vox.
Lawrence Gostin, a global health law professor at Georgetown University, had a similar view. He told Vox, “To get a rate, you need the deaths — which you can more reliably pick up — and you need cases, which you can less reliably pick up. It’s not irresponsible to come out with that number, but it should have been more clearly interpreted as not being reliable, or at least mention it’ll vary in regions.”
A February study by the Chinese Center for Disease Control and Prevention of cases in China found a mortality rate of 2.3%. But the new coronavirus hit the elderly particularly hard: The rate was 14.8% in patients 80 and older and 8% for those 70 to 79.