All around us we see events being canceled due to the novel coronavirus outbreak — despite the fact that a government expert panel has declared that the “domestic outbreak is still at an early stage” and “not yet at an epidemic stage.”
These judgments have been faulted as difficult to justify. But let’s stand back and consider objectively whether the spread of the dreaded coronavirus has reached epidemic proportions here in Japan.
Influenza Numbers and the Definition of ‘Epidemic’
There is a standard definition of “epidemic” in the case of influenza. An epidemic occurs when fixed point observations at the roughly 5,000 hospitals nationwide report on average one or more new cases per week at each hospital.
The Ministry of Health, Labor and Welfare announced in November 2019 that a “nationwide epidemic had started” concerning this year’s strain of influenza. At that time (week 46), the number of influenza patients had reached 9,000 (for a 1.8 average per hospital).
The current number of influenza patients is certainly less than the 11 million patients affected during the major epidemic during the preceding flu season, although there were roughly 300,000 flu patients (average of 60 per hospital) during the sixth week of the season beginning on February 3. According to the National Institute of Infectious Diseases, the total number of flu patients treated during this season has been approximately 6.5 million.
Be Careful Comparing Situations in China and Japan
In contrast, as of February 17, the number of individuals in Japan infected by the novel coronavirus stood at 520, of whom roughly 450 were passengers or crew on the cruise ship Diamond Princess. Within Japan, as of now, there are somewhat more than 156 cases.
To reach the threshold required for this type of influenza to be declared an epidemic according to the abovementioned definition, the number of cases would have to increase 150-fold. Put another way, at this point in time, regular influenza is 100,000 times more dangerous. Consequently, the judgment by the experts’ panel that at this point in time COVID-19 has not yet entered the epidemic phase within Japan is entirely correct.
To refer to an “explosive growth in the number of patients” is to create a jumbled misperception equating the situations in China and Japan. Indeed, even in China the rapid increase in the number of patients has been confined to the city of Wuhan and other parts of Hubei Province.
There is no global epidemic for now.
How Virulent is Coronavirus Compared to Influenza?
It has been said that this novel coronavirus is more virulent than regular influenza, but there really is not much difference between the two. The fatality rate stands at about 2.0%, but the fact is that most of the deaths have been concentrated in the Wuhan region, and even in other regions within China the fatality rate is only about 0.8%.
Deaths in most other countries are nearly zero. And the symptoms appear to be almost identical to those of normal influenza, with many deaths attributable to pneumonia.
Since the fatality rate of regular flu is 0.1%, it is estimated that the number of fatalities within Japan attributable to flu during the current flu season (the excess mortality rate) is around 600. As the graph shows, compared to the historically worst ever flu season of 1998-1999, during which over 37,000 people died from the flu, during the last flu season there were a bit more than 3,000 fatalities. (Source: National Institute of Infectious Diseases)
No Reason to Treat the Coronavirus as Unique
The probability of a person in Japan coming down with the flu this season is about 5.0%, whereas his or her likelihood of contracting the coronavirus is a mere 0.00005%.
Moreover, the chances of that person dying from the coronavirus is essentially zero, with most of the deaths occurring among the elderly or individuals afflicted with a pre-existing underlying condition. Of course, the possibility of an epidemic cannot be ruled out. So the Japanese government needs to take measures to prevent infection, but that goes for influenza as well.
Closing Borders and Canceling Events is Irrational
The loud demands for all visitors from China to be turned back at the border is irrational. If there were absolutely no coronavirus patients within Japan, perhaps such a “water’s edge defensive operation” would make sense. But since the virus has already entered Japan, there is no way to turn it back at the border.
Those countries which are refusing entry to Chinese receive relatively few Chinese visitors. Japan, on the other hand, has nearly 10 million Chinese visitors annually, so such a blanket ban on entry is impossible.
It is meaningless to cancel events and other gatherings. If we are going to implement such a ban for a non-epidemic infectious disease, then we would have to suspend all events occurring during the annual influenza epidemic. Why should it be that we nix events because a mere 156 patients become infected, when we did not do so in 2019 when there were 11 million flu patients?
Focus on Vaccination Against Flu, Not Fear of Coronavirus
Although government measures to contain the novel coronavirus during the early stages of its spread are of course important, the probability of our contracting influenza from contact with a flu patient are exponentially higher.
People fear the new virus because no vaccine has yet been developed to respond to it, but the fact is that instead of fixating on fears of the coronavirus, we should be diligent in getting vaccinated against the more imminent threat of influenza during the cold season.
In other words, there is no reason for special treatment of the coronavirus. Like regular influenza, it is a variant of the common cold. To neglect the 6.5 million influenza patients while pursuing the goal of zero risk from the coronavirus, which has only affected 60 patients, is akin to the desire of those with only limited information who demand zero risk from radiation.
Trade-offs Between Risk and Economics
Whether it be an infectious disease or radiation, there is a necessary trade-off between risk and economics. If you want zero risk, that means that economic activity would have to grind to a complete halt.
Granted that, unlike with radiation, a virus is communicable to other people. But that holds true for regular influenza as well. The responses to the novel coronavirus therefore should be on a par with those for regular influenza.
Nevertheless, one difference between influenza and the coronavirus is the way that the mass media has been stirring up anxiety in the public concerning COVID-19, the disease that the novel coronavirus causes. The damage resulting from rumors and baseless news reports in the form of cancellations of meetings and travel has been considerable.
To counter this situation, the government should eschew overreactions such as event cancellations and the refusal to allow people into Japan.
For their part, mass media organizations have the obligation to provide scientifically accurate information. As with radiation, it is important to correctly evaluate the risks involved.
(Click here to read the original article in Japanese.)
Author: Nobuo Ikeda, PhD
Nobuo Ikeda is a Japanese blogger, and operates the opinion platform Agora.