During this unprecedented global pandemic, it’s become clear that testing for a new disease is anything but straightforward. Various methods to identify COVID-19 carriers have flooded the medical sphere worldwide, with a who’s who of sci-fi-sounding monikers: Polymerase chain reactions, isothermal amplifications, surface spike antigens, medical imaging scans, serology tests and good ol’ throat swabs.

Yet it’s the subdued government responses, insufficient numbers of COVID-19 test kits, baffling false negatives and even more baffling double positives, that have primarily grabbed the headlines. With so much controversy surrounding every testing method, their efficacy has been thrown into question.

In the COVID-19 testing realm, Japan occupies a lonely island among the countries of the developed world.

Japan’s Lackluster Testing

Though Japan seems to have passed the dreaded spike phase and the curve is finally flattening, the fact it has tested a considerably smaller percentage of its population compared to its fellow Group of Seven nations is difficult to ignore.

Ultimately, you can’t find what you don’t look for, and the current approximate figures make for some compelling, if disheartening, reading. As of May 14, Japan had tested 1.8 people for every 1,000 of the population; Italy had tested 28 per 1,000, the UK 21, France 13, Canada 30, Germany 32; even the US was miles ahead with 28 tests per 1,000 (but the data is reportedly sketchy).

Though Japan’s dwindling COVID-19 case-rate has ushered in a nationwide sigh of relief, the reality remains that an ugly truth could be hiding under the rug, ready to unveil itself at any moment.

How to Test for COVID-19

Polymerase chain reactions (PCR tests) are, to date, the most reliable method of diagnosing who has contracted the novel coronavirus. Without getting too deep into the scientific weeds, PCR tests basically detect trace amounts of the virus’ DNA in specimens from your throat, nose or saliva. Complicating matters however, is the deluge of biotech companies championing their own PCR tests, none of which have shown 100% accuracy.

Antibody-searching serology tests have also become popular; Japan’s first kits were approved last week. They identify who has contracted and overcome the virus, and therefore may be immune. When your immune system fights a disease, your white blood cells develop antibodies – warlike proteins attached to the cells – which match directly with specific harmful agents in the body, called antigens. Serology tests aim to find the unique antibodies generated to fight COVID-19.

Though the veracity of antibody tests has been debated, Sky News reported Thursday that Swiss medical company Roche had developed a 100%-accurate testing kit. This could be a game-changer in the push to reopen societies.

The Stumbling Japan Model

Japan’s drive to combat the virus has been based on cluster identification and contact tracing, as opposed to mass testing. This method focuses on identifying disease clusters – large portions of COVID-19 carriers that frequented the same area, such as the hospital breakout in Tokyo’s Taito Ward – and tracking down all people who have recently come into contact with these known carriers. Those who come into prolonged contact with a carrier, are then required to self-isolate for 10 to 14 days.

The model failed to hold up, however, when patients diagnosed with COVID-19 forgot who they’d come into contact with – especially when clusters were found in clandestine hostess bars. At the same time an explosion in the number of COVID-19 patients with no known source of infection, leant the Japan model no further credence.

The Olympic Effect

It seems the ill-fated Tokyo 2020 Olympics also had a hand in shaping decisions. Both Prime Minister Shinzo Abe’s administration and head of the Games’ organizing committee, Yoshiro Mori, were adamant the Olympics would go ahead as planned, even as late as mid-March.

The general consensus among critics at the time was: more testing equals more COVID-19 cases, which in turn equals no Olympic Games, and that is not a concession the government is willing to make.

The announcement to postpone the Games was made on March 24, while in virtually the same breath Japan’s number of COVID-19 tests and confirmed cases began to increase. The harsh irony of this was not lost on commentators.

“In order to make an impression that the city was taking control of the coronavirus, Tokyo avoided making strict requests and made the number of patients look smaller,” said former Prime Minister Yukio Hatoyama in a barbed tweet.

What is Enough Testing?

But what constitutes enough testing?

“We have a simple message for all countries: Test, test, test. Test every suspected case,” said WHO Director-General Tedros Adhanom Ghebreyesus during a press conference in March.

Vox News quantified this same idea in an article last month, outlining think tank proposals on how many tests were needed to lead us into a post-pandemic world. For the United States (population 328 million), estimates ranged from 750,000 tests per week to over 20 million per day. Taking population into account, the most conservative estimates for Japan would suggest it requires approximately 280,000 tests every week.

Japan has conducted just under 220,000 tests total since February.

Why Japan Needs More Testing

Japan’s infection rate continues to wane, so why test more people?

First, there is the problem of asymptomatic carriers. Many who contract COVID-19 will express no symptoms at all. But to supress the spread of the virus effectively, it’s vital to know who’s carrying it, irrespective of whether they get ill. Conversely, Japan’s official guidelines for doctors recommends they should only issue a COVID-19 test if a patient has pneumonia – in part, to appease the strained medical system.

Meanwhile the economy is also plunging into an abyss. To safely reopen society, Japan needs to know exactly where on the curve it lies. Professor Kenji Shibuya of Kings College London told the BBC he was “very worried” about Japan’s situation, estimating that 20 to 50 times more people may be infected than currently believed – up to 700,000 people. Japan has expressed no interest in increasing the number of tests to verify such claims.

Nevertheless, Abe announced that the state of emergency is now lifted in 39 of Japan’s 47 prefectures, and it could be lifted for the remaining eight prefectures as soon as May 21. We just have to hope the paltry data is somewhat representative of reality.