Editor’s note: This story is excerpted from an article that appeared recently in Geopolitical Futures, an online-only subscription publication. Alex Berezow is a Seattle-based Ph.D. microbiologist, vice president of scientific communications at the American Council on Science and Health and a senior analyst at Geopolitical Futures.
For the general public, the most important question about COVID-19 coronavirus is personal: “Might I – or anyone I love – get sick and die?”
The first substantial effort to develop a “risk of death” profile for COVID-19 was published by the Chinese Center for Disease Control and Prevention. Though these numbers should be thought of as preliminary (and perhaps specific to only China), they allow us to begin to comprehend the risk our global society is facing. After analyzing 44,672 confirmed cases, Chinese health officials estimated the case-fatality rates by age group:
- Of the 416 children aged 0 to 9 who contracted COVID-19, precisely zero died. This is unusual for most infectious diseases, but not for coronaviruses. The SARS coronavirus outbreak also had minimal impact on children.
- For patients aged 10 to 39, the case-fatality rate is 0.2 percent.
- The case-fatality rate doubles for people in their 40s, then triples again for people in their 50s, and nearly triples yet again for people in their 60s.
- A person who contracts COVID-19 in their 70s has an 8 percent chance of dying, and a person in their 80s a nearly 15 percent chance of dying.
The virus can be lethal in a variety of ways. Viral infections can trigger an immune response so strong that it fatally damages the lungs. In others, a systemic immune response, called a “cytokine storm,” can cause multiple organ failure. This could explain why some young, healthy people are killed by the virus, such as Dr. Li Wenliang, the 34-year-old who died shortly after alerting the world to this new strain of coronavirus. Underlying conditions such as high blood pressure or diabetes can worsen outcomes.
The above statistics are no doubt frightening. But there are at least three major mitigating factors.
First, the number of mild or asymptomatic cases is unknown and probably substantial. Second, China is still a poor country with low-quality health care. Third, smoking is much more prevalent in China than America, especially among men (52 percent in China versus 16 percent in the U.S.). Smoking is a risk factor for poor responses to respiratory infections.
Together, this means the China’s case-fatality rate is likely inflated, and it would be a mistake to apply these figures to the United States or other advanced nations.
At this point, it’s impossible to determine how inflated the case-fatality rates are because scientists still are collecting data. But if COVID-19 ends up being similar to seasonal influenza, then the case-fatality rates for COVID-19 are inflated by a factor of 20 to 100.
(Here Berezow quotes an editorial in the New England Journal of Medicine, which said the case fatality rate may be considerably less than 1% if one assumes that the number of cases with no or mild symptoms is several times higher than the number of reported cases.)
We have reason to believe this view is closest to reality. In South Korea, public health officials screened about 100,000 people and detected over 7,300 cases. So far, the death toll is 50, a case-fatality rate of 0.7 percent. That’s still seven times worse than seasonal flu, but it’s far lower than the initial reports from China.
Stat News describes two possible scenarios that epidemiologists envision for the future of COVID-19. In the first, COVID-19 becomes just another cold virus, and it possibly evolves to become less lethal as well. The “common cold” actually is caused by roughly 200 different viruses. Each year, about 25 percent of common colds are due to four coronaviruses, and some scientists think COVID-19 could eventually join this group as its fifth member. In the second scenario, COVID-19 evolves into a severe seasonal flu, vanishing in the summer and returning in the winter.
In neither scenario does COVID-19 resemble the Spanish flu of 1918, which disproportionately killed young people. In neither scenario does the virus mutate to become more lethal. Most likely, the opposite will be true. The most contagious viruses tend to be less lethal. Evolutionary pressures – namely, the biological imperative to reproduce as far and wide as possible (which means not killing people) – may push COVID-19 down this path.
For now, influenza remains the far bigger global public health threat. Each year, about 1 billion people become infected with seasonal flu, killing some 300,000 to 500,000. This season alone (2019-20), about 20,000 Americans have died from flu, including 136 children. Yet, very few people fear the flu. Society has accepted it as part of reality, and people carry about their daily lives without excessive concern over influenza. This is the likely future for COVID-19.
Until then, perhaps the last word should be given to virologist Dr. Lisa Gralinski, who told “The Scientist”: “If you’re over 50 or 60 and you have some other health issues and if you’re unlucky enough to be exposed to this virus, it could be very bad.” While everyone else should remain vigilant and take proper precautions (e.g., washing hands and avoiding crowds) until more data comes in, from a scientific perspective the public alarm is disproportionate to the risk.
Copyright 2020 Geopolitical Futures, LLC. Republished with permission.
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