At the Wall Street Journal Eran Bendavid and Jay Bhattacharya explain why COVID-19 may be a lot less deadly than the present reaction would seem to indicate:
Fear of Covid-19 is based on its high estimated case fatality rate—2% to 4% of people with confirmed Covid-19 have died, according to the World Health Organization and others. So if 100 million Americans ultimately get the disease, two million to four million could die. We believe that estimate is deeply flawed. The true fatality rate is the portion of those infected who die, not the deaths from identified positive cases.
The latter rate is misleading because of selection bias in testing. The degree of bias is uncertain because available data are limited. But it could make the difference between an epidemic that kills 20,000 and one that kills two million. If the number of actual infections is much larger than the number of cases—orders of magnitude larger—then the true fatality rate is much lower as well. That’s not only plausible but likely based on what we know so far.
Population samples from China, Italy, Iceland and the U.S. provide relevant evidence. On or around Jan. 31, countries sent planes to evacuate citizens from Wuhan, China. When those planes landed, the passengers were tested for Covid-19 and quarantined. After 14 days, the percentage who tested positive was 0.9%. If this was the prevalence in the greater Wuhan area on Jan. 31, then, with a population of about 20 million, greater Wuhan had 178,000 infections, about 30-fold more than the number of reported cases. The fatality rate, then, would be at least 10-fold lower than estimates based on reported cases.
Next, the northeastern Italian town of Vò, near the provincial capital of Padua. On March 6, all 3,300 people of Vò were tested, and 90 were positive, a prevalence of 2.7%. Applying that prevalence to the whole province (population 955,000), which had 198 reported cases, suggests there were actually 26,000 infections at that time. That’s more than 130-fold the number of actual reported cases. Since Italy’s case fatality rate of 8% is estimated using the confirmed cases, the real fatality rate could in fact be closer to 0.06%.
In Iceland, deCode Genetics is working with the government to perform widespread testing. In a sample of nearly 2,000 entirely asymptomatic people, researchers estimated disease prevalence of just over 1%. Iceland’s first case was reported on Feb. 28, weeks behind the U.S. It’s plausible that the proportion of the U.S. population that has been infected is double, triple or even 10 times as high as the estimates from Iceland. That also implies a dramatically lower fatality rate.
What all of this tells us is that we just don’t know. Ignore the Chinese statistics. We should treat them a PR rather than a guide for policy. But the findings from Italy and Iceland, in particular, are interesting. A mortality rate of 2% with a prevalence of 1% is more analogous to another seasonal flu than it is to the Black Death.
I want to emphasize three things. First, the purpose of the lockdowns, bans on large gatherings, and so on is not to reduce the number of people who will become infected by COVID-19. It is to pace the number of those who become seriously ill so that they do not overwhelm our health care system. It would be tragically irresponsible if we do not, simultaneous with that attempt, exert at least as much effort to increasing the size of the available resource with all due speed.
We have no reason to believe that COVID-19 won’t be with us forever. It should be obvious that the lockdowns can’t persist forever. What is needed is a modus vivendi with the persistent presence of COVID-19. As I have been pointing out we have lived with diseases that can kill before and we will need to learn to do so again.
Finally, we simply do not know and just “more testing” will not provide us with the knowledge we need. We need well-designed epidemiological testing before we really can understand the scope of what we’re dealing with. Diagnostic testing of individuals who present themselves at the hospital or putative testing centers won’t do that. Such testing would be a good job for the federal government but, if Washington won’t do it, we may be forced to do it ourselves. Maybe some trusted health care organization needs to start a “Go Fund Me”. As G. K. Chesterton observed, there are some things that are too important to be trusted to the state.