A PCR, or polymerase chain reaction, test for the novel coronavirus underway at a health care center in Edogawa Ward, Tokyo, on May 19. Photo: AFP

Talk about swerving Armageddon.

Mere weeks ago, media and pundits worldwide saw Japan, with its minimalist testing regimen, teetering on the brink of a coronavirus catastrophe. Massive outbreaks were widely foreseen, hospitals were expected to be overrun and the medical system, many anticipated, would implode.

Yet on May 26, Japan ended its state of emergency – a state that was far less strict than many of the lockdowns instituted elsewhere – without this apocalyptic outcome coming to pass.

The numbers of infected remain low with less than 1,000 people dying in a nation of 126 million.

Despite its ultra-low testing rate of 0.2% of the population, Japan had a plan. It seems to have worked, and a key pillar of the country’s unexpectedly successful coronavirus countermeasures has been contact tracing.  

It is based on a simple theory, put forward by the Ministry of Health, Labor and Welfare: “The spread of infection can be prevented by tracing the route of transmission, especially for close contacts. The important thing is to minimize the spread of infection in the country by preventing one cluster of patients from creating another cluster.”

The system is due to get an upgrade this month with the introduction of a contact tracing smartphone application. Remarkably, given how digitally savvy most Japanese are, the methodology used so far has been almost stubbornly analog.

Long history

While South Korea and Taiwan had to deal with SARS and MERS, which helped them prepare for the novel coronavirus, Japan’s ancient enemy has been a different respiratory illness: tuberculosis. 

Toshio Takatorige, a professor of public health at Kansai University, explained in an interview published by Kyodo News on May 25 that Japan’s long battle with TB prepared it to handle the novel coronavirus.

In 2018, 16,789 Japanese contracted tuberculosis and more than 2,200 died – more than double the number – 892 – who have succumbed to Covid-19 so far. Japan has the world’s oldest population, as well as a significant influx of overseas workers, which has added up to a surprisingly major TB risk for such a prosperous nation.

Japan was an early mover in national healthcare and the current system was established in 1937. Takatorige asserts the reason Japan was able to deal more effectively with Covid-19 than Europe and the US is its hundreds of public health centers, originally designed to cope with TB.

The system’s core was the Tuberculosis Prevention Association, which handled research, the development of countermeasures and the training of public health center workers. Today, the centers are not staffed by doctors. They are administrative, rather than treatment facilities.

From this grew Japan’s present public health care center-orientated approach to infectious diseases. Because hospitals are often vectors for infectious diseases, the professor notes, a key role for the 469 public health centers is as “gate guardians,” determining who should be tested, thereby discouraging people from overrunning the hospitals.

The centers have been the front line in Japan’s Covid-19 fight as clearing houses for coronavirus tests. Their workers leave the facilities and venture into communities to collect samples for testing, transport samples to medical facilities, inform patients of the results and conduct contact tracing.

Analog approach

From the get go, the Ministry of Health, Labor and Welfare believed the transmission of Covid-19 had characteristics that mandated a different approach to containment.

They observed that regardless of the severity of their illness, 80% of patients who contracted the disease did not infect others. The remaining 20% infected others, but there also appear to be “super-spreaders” – individuals infecting many others, creating a cluster. 

Most countries have approached contact tracing as “prospective” investigations – tracking down all close contacts of the infected as potential future cases to be tested and perhaps quarantined. 

Japan, however, emphasized “retrospective” contact tracing – following leads, like a detective, to the source of the infection and documenting the chain of transmission to trace clusters of multiple cases to a common source.

“Often it’s not the person who tested positive for the coronavirus that is spreading the disease, it’s the person that gave it to them – a sort or super-spreader or “Patient Zero,” a Ministry of Health official, speaking on background, noted.

“Going back to the source is the goal of retrospective contact testing and that’s based on an evolving understanding of how a coronavirus works and spreads.”  

Retrospective contact tracing seeks to identify the source of outbreaks and then, from that highly infectious source, contact others who might have been infected. They could then begin early treatment of the infected, and work to stop the spread to other areas and more people. This also helped contain infections within regions. 

Contact tracers in each Public Health Center work like detectives. Investigations are low-tech, with information kept on white-boards, in printed binders and sometimes paper charts on the wall. Workers make phone calls, send emails and leave the office to do actual legwork to figure out where the latest outbreak originated. 

The goal is to investigate activities around multiple cases, to determine the place or person that was the common source of transmission. They then make exhaustive efforts to find all the people who came into contact with the source. 

Compared to, say, South Korea – which has integrated immigration, police, CCTV, mobile phone, public transport and credit card company databases, then boosted them with AI to enable automated, nationwide contact tracing within literally 10 minutes – it is an almost quaintly old-fashioned methodology.

But it appears to have been remarkably successful.

“All contact tracing has been based on methods that were and are used to track tuberculosis patients, past and present,” the official noted. “We made the best use of methods and systems already in place.”

Upgrading to app 

This analog method is – finally – about to get a digital upgrade. In early May, the government announced plans to make a coronavirus contact-tracing application available, with the cooperation of Google and Apple. It is still in development.

Singapore and other countries have introduced high-tech applications to track coronavirus cases. South Korea, for example, has made a personal health-check app a mandatory download at all airports and ports for all incoming visitors.  

The app Japan is designing will record the data of smartphones that come within a certain distance of each other, probably using Bluetooth. Users will then be alerted if they have been in close contact with someone diagnosed with the virus – assuming that person is using the app as well. The app will not track phone numbers and location data, to protect  privacy.

Full details are not yet public, but the Nikkei Newspaper reported on Tuesday that there have been glitches that may slow its release until mid- or late June.

This being Japan, there will be no requirement to use the application, meaning cooperation from the general public will be needed. But so far, the Japanese public has been remarkably collaborative with anti-virus measures.

A health-care worker at the Minato Public Health Center says he does not consider the application a game-changer.

“The data from the app will let more people know if they have possibly been infected, but we will still be on the ground floor advising people as to whether to get tested, where to get tested, and when positive test results emerge – and we will be tracing infections back to the source,” he said.

The core issue is a community approach.

“An app can only do so much. AI, artificial intelligence, can also help, I suppose, but it really comes down to people,” the worker insisted. “You need people to find infected people. We do that well.”