As the threat of COVID-19 spreads around the world, countries are developing strategies to limit the death toll while maintaining economic activities. Though many countries around the world, such as European countries and the United States, have imposed substantial behavioral restrictions — so-called lockdown measures — while conducting massive testing and isolation, Japan has managed to control the situation without taking such measures.
Despite the increase in the number of new cases since late March and the declaration of a state of emergency on April 6, the number of deaths per million people in Japan was 7.65 as of Thursday, which is relatively low compared to other countries (368.51 in the United States, 572.99 in Italy, 634.61 in the United Kingdom, 106.55 in Germany, and 5.50 in South Korea).
In Japan, countermeasures have been taken based on an analysis of COVID-19, which is characterized by a large proportion of asymptomatic cases among the infected. Most of these asymptomatic cases do not spread the infection, but a small proportion of them — so called super-spreaders — infect multiple people, resulting in a pattern of clusters of new infections.