What began with a handful of mysterious illness in a vast central China city has traveled the world, jumping from animals to humans and from obscurity to international headlines. First detected on the last day of 2019, the novel coronavirus has infected tens of thousands of people-within China’s borders and beyond them – and has killed more than 8,272. It has triggered unprecedented quarantines, stock market upheaval and dangerous conspiracy theories. Indeed, most cases are mild, but health officials say the virus’s spread through the United States appears inevitable. As the country and its health care system prepares, much is still unknown about the virus that causes the disease now named COVID-19.
There are many compelling reasons to conclude that SARS-CoV-2, the virus that causes COVID-19, is not nearly as deadly as is currently feared. But panic has set in nonetheless. Hand sanitisers are scarce and N300 face masks are being sold online for exorbitant prices, never mind that neither is the best way to protect against the virus. The public is behaving as if this pandemic is the next Spanish flu, which is frankly understandable, given that initial reports had staked COVID-19 mortality at between 2 and 3 per cent, quite similar to the 1918 pandemic that killed tens of millions of people.
Allow me to be the bearer of good news. These frightening numbers are unlikely to hold. The true case fatality rate, known as CFR, of this virus is likely to be far lower than current reports suggest. Even some lower estimates, such as the 1 per cent death rate recently mentioned by the directors of the National Institutes of Health and the Centers for Disease Control and Prevention, likely substantially overstate the case. We shouldn’t be surprised that the numbers are inflated.
In past epidemics, initial CFRs were floridly exaggerated. For example, in the 2009 H1N1 pandemic some early estimates were 10 times greater than the eventual CFR, of 1.28 per cent. Epidemiologists think and quibble, in terms of numerators and denominators-which patients were included when fractional estimates were calculated, which weren’t, were those decisions valid-and the results change a lot as a result. We are already seeing this.
In the early days of the crisis in Wuhan, China, the CFR was more than 4 per cent. As the virus spread to other parts of Hubei, the number fell to 2 per cent. As it spread through China, the reported CFR dropped further, to 0.2 to 0.4 per cent. As testing begin to include more asymptomatic and mild cases, more realistic numbers are starting to surface. New reports from the World Health Organization (WHO) that estimate the global death rate of COVID-19 to be 3.4 percent, higher than previously believed, is not cause for further panic. This number is subject to the same usual forces that we would normally expect to inaccurately embellish death rate statistics early in an epidemic. If anything, it underscores just how early we are in this.
Here’s the problem with looking at mortality numbers in a general setting: In China, 9 million people die per year, which comes out to 25,000 people every single day or around 1.5 million people over the past two months alone. A significant fraction of these deaths results from diseases like emphysema/COPD, lower respiratory infections, and cancers of the lung and airways whose symptoms are clinically indistinguishable from the nonspecific symptoms seen in severe COVID-19 cases. And, perhaps unsurprisingly, the death rate from COVID-19 in China spiked precisely among the same age groups in which these chronic diseases first became common.
During the peak of the outbreak in China in January and early February, around 25 patients per day were dying with SARS-CoV-2. Most were older patients in whom the chronic diseases listed above are prevalent. Most deaths occurred in Hubei province, an area in which lung cancer and emphysema/COPD are significantly higher than national averages in China, a country where half of all men smoke. How doctors were supposed to sort out which of those 25 out of 25,000 daily deaths were solely due to coronavirus, and which were more complicated? What we need to know is how many excess deaths this virus causes.
This is where the Diamond Princess data provides important insight. Of the 3,711 people on board, at least 705 have tested positive for the virus (which, considering the confines, conditions, and how contagious this virus appears to be, is surprisingly low). Of those, more than half are asymptomatic, while very few asymptomatic people were detected in China. This alone suggests a halving of the virus’s true fatality rate. On the Diamond Princess, six deaths have occurred among the passengers, constituting a case fatality rate of 0.85 percent. Unlike the data from China and elsewhere, where sorting out why a patient died is extremely difficult, we can assume that these are excess fatalities-they wouldn’t have occurred but for SARS-CoV-2. The most important insight is that all six fatalities occurred in patients who are more than 70 years old. Not a single Diamond Princess patient under age 70 has died. If the numbers from reports out of China had held, the expected number of deaths in those under 70 should have been around four.
This all suggests that COVID-19 is a relatively benign disease for most young people and a potentially devastating one for the old and chronically ill, albeit not nearly as risky as reported. Given the low mortality rate among younger patients with coronavirus-zero in children 10 or younger among hundreds of cases in China, and 0.2-0.4 percent in most healthy nongeriatric adults (and this is still before accounting for what is likely to be a high number of undetected asymptomatic cases)-we need to divert our focus away from worrying about preventing systemic spread among healthy people-which is likely either inevitable, or out of our control-and commit most if not all of our resources toward protecting those truly at risk of developing critical illness and even death: everyone over 70, and people who are already at higher risk from this kind of virus.
This still largely comes down to hygiene and isolation. But in particular, we need to focus on the right people and the right places. Nursing homes, not schools. Hospitals, not planes. We need to up the hygienic and isolation ante primarily around the subset of people who can’t simply contract SARS-CoV-2 and ride it out the way healthy people should be able to.
Orubon writes from Abeokuta, Ogun state