When Shinzo Abe ended a nationwide state of emergency last week with just 16,724 infections and 894 deaths from Covid-19, he could not resist bragging about the “Japan model” for handling coronavirus.
“In a characteristically Japanese way, we have all but brought this epidemic under control in the last month and a half,” the prime minister declared. He lavished praise on the public but Mr Abe’s remarks begged a question: what is this Japan model and could it work anywhere else?
Although there has been a surge in cases in Tokyo, understanding the reasons for Japan’s relative success in controlling Covid-19 has global significance. After all, the country did not impose a compulsory lockdown and carried out little virus testing, two elements other nations regard as crucial.
Much public debate in Japan had turned on cultural factors — such as high standards of hygiene, obedience to government requests and even claims that the lack of aspirated consonants in the Japanese language reduces the spread of virus droplets. But local experts do not believe their country has any magic power to defeat the virus.
Instead they point to three more prosaic factors: a special contact-tracing strategy, early awareness that brought a positive reaction from the Japanese public and the timely declaration of a state of emergency.
Japan was hit early by the epidemic because of its close links to China. The country reported its first case on January 15 and its first domestic infection on January 28. In early February, at a time when most of the world was still treating Covid-19 as a Chinese problem, Tokyo handled an outbreak on the Diamond Princess cruise ship.
“Japan realised what was happening and started reacting before the virus took hold,” said Satoshi Hori, an expert on infection control and a professor at Juntendo University. “It was a locational advantage.”
Without any official instruction, the public began hand-sterilising, wearing masks and social distancing of its own accord.
“Everyone wore masks to protect themselves but the real effect was to reduce spreading by asymptomatic carriers of Covid-19,” said Prof Hori. “It may have been luck but it did make a difference.”
Japan used a particular approach to contact tracing. “Most other countries adopted what we call prospective tracing,” said Shigeru Omi, head of the expert panel advising Mr Abe on the virus. “The cluster-based approach uses thorough retrospective contact tracing to identify common sources of infection.”
In prospective tracing, the close contacts of a Covid-19 case are monitored so they can be quarantined if they show symptoms. Japan’s approach also tries to find out where they were infected, be it a nightclub or a hospital, and then monitor people who visited that site.
Four out of five coronavirus patients do not infect anyone else, so Dr Omi said that finding the superspreaders was a more efficient way to control the disease.
Kenji Shibuya, a public health expert at King’s College London, said cluster control worked well until early March but eventually coronavirus began to circulate in Japan’s big cities.
Slowing the outbreak’s growth helped Mr Abe to declare a state of emergency at the right moment, when the number of cases was still manageable.
“If the decision had been made a week later then the number of cases would have exploded,” said Prof Shibuya, comparing the timing of Japan’s declaration with lockdowns in Italy and the UK.
The state of emergency did not force people to stay at home but many respected the plea. “Japan’s mild lockdown seems to have had a real lockdown effect,” he said.
Other countries might not have had the same level of compliance with a voluntary request, said Prof Hori.
Prof Shibuya said Japan’s approach was not perfect and other Asian countries had done better. He said more testing was vital. “Because they lacked the tests, they couldn’t prevent exponential growth in Tokyo and the big cities,” he said.
“It’s obvious the virus is still circulating. The next wave will definitely come and we need to prepare.”
On Tuesday, the number of new cases in Tokyo rose to 34, the highest in two weeks.
Dr Omi acknowledged that Taiwan and South Korea had responded better than Japan but said that was due to their virus experience with Sars in 2003 and Mers in 2015.
“Taiwan and Korea were hit. That alerted the country concerned.” Japan had prepared, he said, but not to the same degree.