After getting depressed by hundreds of irrational comments on the Facebook page attached to this site, I thought I’d put a post on the Epidemiologist’s Facebook Page, that has over 4,000 Epidemiologists registered with it from all over the World. (https://www.facebook.com/groups/2356665886/ )

I gave a simple challenge: explain why two cities, New York and Tokyo, have a death rate that varies by OVER TWO HUNDRED TIMES. This is a truly colossal difference, varying by more than two Orders of Magnitude (In simple terms, you have to multiply the Japanese figure by ten, and then by ten again, to get to the same ball park as the USA figure.)

Here’s the Post:

A TALE OF TWO CITIES – NEW YORK AND TOKYO

More accurately two metropolises; New York Metropolitan District has 20 million people, Greater Tokyo almost double that. NY had its first confirmed case on 1st March. Tokyo seems to have had its first local case, a taxi driver, on 24th January, over a month earlier. The SIR Model charts from Singapore University of Technology and Design, which are for whole countries rather than cities, reflect the earlier start in Tokyo. The prediction from the graphs is that the epidemic will be 97% finished on almost the same day, 13th or 16th May. New York has had a very harsh lockdown, Tokyo has used a very mild one. New York has over 23,000 fatalities, Tokyo has just 108.

These massively different numbers are begging for an explanation. Politicians and journalists will never manage it. It’s for Epidemiologists. I’m looking forward to other people’s answers.

End of Post

NOT included in the post was the image below that puts the Japanese data on the same scale as the USA data. I assumed epidemiologists can easily notice and handle different scales on graphs, whereas most people don’t. The adjusted graphs make the difference far clearer.

In 24 hours the post scored 19 likes, no dislikes, 5 shares, and 11 people jumping in to answer, with the debate swelling to nearly 3,000 words, most of which where probably mine. Factors suggested to account for the difference were Vitamin D deficiency, end of first wave, population density, wearing masks, greater outbreak in New York, more people flying to NY from Wuhan, spitting in the street, amount of testing, epidemiologists are stupid, Japanese have hereditary immunity from Covid19, and lockdown is the wrong thing to do in an epidemic.

As I pointed out the problems with people’s suggestions, they tended to go quiet. Even though I dropped hints in the original post, and in my replies, to the answer, nobody got it. This is extremely worrying. It seems that even Epidemiologists, who should jump to the correct answer, have been baffled by the media reports. Only one of the answers was partly correct: the one that referred to immunity in Japan. But that answer ascribed the immunity to an inherited immunity. There is no known virus that affects only certain races, so this was a very strange assumption to make.

For ordinary mortals who also don’t know the answer, here it is. The clue is in the first Tokyo case being over a month before NY. Airborne Upper Respiratory infections come and go pretty quickly. The noticeable part of the epidemic is probably only three weeks or so. By “noticeable” I mean the part of it where medics, and possibly others, would know there was something going on without the TV telling them. Covid19 is a hidden infection in the sense that symptoms are essentially the same as other Upper Respiratory infections, so, especially in a flu season, people won’t notice anything different going on. This, by the way, is why people are crying out for testing. Without it, we simply don’t know if someone had a cold, a flu, or Covid19.

So, the virus spread in Japan, as well as in China and other countries neighbouring China, without being noticed. When people got wise (or stupid) to it, they started reacting and recording cases. As they got more tuned in to this, they recorded an increasing number of cases, until the cases fell away because they were already at the tail end of the epidemic. All epidemics caused by new diseases are naturally self-limiting. As they progress through a population immunity builds up through contact. Most people become immune without ever knowing it. And when the level of immunity reaches a certain point, the epidemic ends, and everything can go back to normal. (See explanation of Epidemiology here.)

In New York, all the lockdown, social distancing, etc made no difference. The virus was already established in the city, and went through it like a dose of salts, regardless of the restrictions. The New York figures are probably also inflated, according to a lot of credible local reports. These all focus on deaths recorded as Covid when they weren’t, and people in Care Homes being hastened on the way to their demise.

The key takeaway from this is that Covid is a flu-like illness producing a standard, self-limiting epidemic pattern. Without the media hype, most of us would have thought little, if anything, of it. Most people have no serious experience of it, except for the “proof” of its danger provided by the big new hospitals, empty streets, closed airports, collapsing businesses, etc. Note that the UK death rate of 405 per million equals 0.4 of a death per thousand. Most people only know about 100 others personally, so the chance of anyone knowing someone who dies personally is vanishingly small.

I’m reminded of a story my Dad used to tell back in the day when mental hospitals were enormous institutions based in large parkland outside the city. A visitor to one saw a man spreading white powder from a paper bag on the ground. The visitor asked what it was, and the answer was “Elephant Powder.” The visitor moved on, but several days later saw the man again spreading the powder in a different part of the grounds. Asking again what the powder was, he got the same answer. Forgetting momentarily that he was visiting a mental institution, he said “But there’s not an elephant within a thousand miles of here!” “Absolutely,” came the reply: “Brilliant stuff, isn’t it!”

With thanks to Dr Knut Wittkowski for telling the truth, and my Dad for the joke.