While we don’t know where we get infected, Japan is massively...

“Look at the forest, not just the trees,” says Japanese virologist Hitoshi Oshitani. That insight is the basis of the now acclaimed Japanese model in the fight against Covid-19. Japan doesn’t look for who infected you, but where you picked up the virus. ‘The data prove it: our approach is more efficient than that in the West. Through all that testing, you are in a war of attrition. ‘

“We are sailing blind,” says biostatistician Geert Molenberghs (UHasselt and KU Leuven). He is referring to the total lack of knowledge about where we are infected with Covid-19. Do we catch the virus while sitting at a café with friends, or during the coffee break at work? Or is the spread mainly at home, through contacts with our family? And is it the children who get the virus at school or in the youth movement from a friend who then bring it home? Or are the now forbidden musty changing rooms after the weekly indoor football match the hotspots of corona infections?

We do not have that information, despite all efforts to trace contact – you have probably already left your name and telephone number dozens of times at a café or restaurant, but the times you subsequently received a message that the pleasant man at the table next to you was on the fingers of one hand.

In the Netherlands and Germany they now know that. In the Netherlands, nearly 60 percent of infections take place at home, 13 percent at work and barely 1.8 percent in the catering industry. But determining it alone is not enough, policymakers should also do something with it, says Molenberghs. And that is exactly what they have been successfully proving in Japan for months now: they are not looking for who infected you, but where you were infected. According to Antwerp governor Cathy Berx and microbiologist Herman Goossens (UAntwerpen), we should also apply this strategy.

8 out of 10 patients do not infect anyone

Hitoshi Oshitani, a virologist at Tohoku University and a member of the panel advising the Japanese government on corona strategy, said one early discovery was of great importance. “We soon saw that the vast majority of people with corona did not infect others, so there had to be only a small minority that passed on the virus. At the same time, the local health services identified places where several residents had become infected at the same time, ”says Oshitani.

He refers to research in Hong Kong during the first wave in March and April. This shows that 80 percent of the infections are caused by 20 percent of the patients. The remaining 20 percent is the work of another 10 percent of the patients. In other words: eight in ten carriers of the corona virus do not infect anyone at all.

So back in March in Japan, they started looking for that one super-diffuser – the one that is highly contagious, through highly targeted on-site source tracing. The bartender at the local karaoke club, or the yoga instructor at a busy fitness center, for example. The state of emergency was briefly declared in the first wave, but in the meantime there is only the advice to avoid the ‘san mitsu’: crowded places, dense spaces with poor ventilation and dense conversations with other people. “Contact tracing like you do is not that effective,” Oshitani said in De Standaard last weekend.

“Most people don’t pass it on to their high-risk contacts. So you will not find the most important cases. And it takes a lot of time and manpower. We look for common features between cases. People are asked about their activities, and in particular whether they have visited a risky environment. Think of a karaoke bar, for example. We have not found the common source for many infections, but we have for many others. You can then trace people who were in the same place on the same day. That is a much more effective way to find cases than to just search the contacts of an infected person. ”

5 dead in 126 million Japanese

There is no question of a lockdown in Japan – also because it is legally prohibited. On August 3, they peaked – barely – 1,998 new infections, out of a total population of nearly 126 million people. On October 13 there were only 326. This low number can also be explained by the low number of tests, because the government does not believe in massive testing. But the number of Covid-19 deaths remains very low: on September 5 there were 19 – the highest number in the second wave. Last Monday 5 more people died. In Belgium, with 11 million inhabitants, we have an average of 18 deaths per day.

In the meantime, the whole world is looking at the Japanese approach, because it is gradually becoming clear that, thanks to the targeted detection of super spreaders, existing sources of infection will not spread further. Japanese hotel chains even offer rooms where, for those who are infected, have mild symptoms and may be a super diffuser, it is more pleasant to be in isolation than in a cramped apartment.

‘Mori wo Miru’

“You have to see the forest, not the trees”, Oshitani expresses the principle that has since become famous worldwide – ‘Mori wo miru’, in Japanese. In Gaiko magazine, he recently explained the difference with the Western approach: “The data clearly shows that our approach is more efficient than that in Western countries, where the focus is on mass testing of everyone who has come into contact with an infected person. which then leads to even more testing. In this way people in the West try to eliminate the infections one by one. This way you end up in a war of attrition. It may be a strange thought for a Westerner not to get tested if you have been in contact with an infected person. But by organizing that, you create chaos. And: busy environments in waiting rooms at doctors or hospitals, where people can infect each other even more. ”