Japan’s Pragmatic Approach to COVID-19 Testing

  • Category:Other

At this point it is necessary to develop a stepwise approach from the end of the state of emergency to a final exit strategy.

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 June 25, 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.

Based on this scientific finding, Japan decided to prioritize preventing clusters from spawning new clusters by retroactively tracing the chain of transmission. Under this strategy, the Japanese government conducts rigorous contact tracing; therefore, given its finite testing capacity, Japan’s testing operations are focused on potential and identified clusters as opposed to mass testing.

From the beginning, Japanese testing operations were pragmatic and unique compared to those in other countries. Due to free access to healthcare facilities and low out-of-pocket payments, there was a concern that people would rush to medical facilities to get tested due to anxiety about the disease, resulting in nosocomial infections at medical facilities and depletion of medical resources.

Besides that, under Japan’s Infectious Disease Act, at the very early stage of the outbreak, any person testing positive for COVID-19, whether symptomatic or not, was required in principle to be hospitalized at a medical facility, and there was a concern that hospital beds would quickly become occupied by patients with mild symptoms, which would result in inadequate treatment of severe cases.

For this reason, the Ministry of Health, Labor, and Welfare (MHLW) recommended that patients without any underlying conditions be kept at home, and that testing capacity be focused on people who had had close contact with COVID-19 patients as well as older persons with underlying conditions.

Japan’s unique testing policy has been criticized both within and outside of the country, despite the low number of deaths in Japan. There is a concern that the actual status of the epidemic in Japan may be inadequately captured, primarily because of the small number of PCR tests.

However, compared to other countries, the positivity rate in Japan (the number of positive PRC test results as a percentage of total PCR tests performed) is relatively low at 5.5 percent (compared to 6.0 percent in Germany, 17.4 percent in the United States, and 26.9 percent in the United Kingdom), indicating that Japan has been adequately detecting COVID-19 cases.

In addition, given that there are evidently a significant proportion of asymptomatic cases among the infected, it does not necessarily make sense to attempt to ascertain the prevalence of infection by PCR. In fact, in other countries, PCR testing alone turned out not to be sufficient to determine the full extent of the epidemic in the population, and antibody testing is now being considered to determine the actual status of the epidemic.

Although the accuracy of antibody testing remains questionable so far, the actual number of cases appears to be several times to several dozen times higher than that captured by PCR, a result which is being found not only in Japan but also in other countries.

The preliminary findings of the prevalence of COVID-19 detected by antibody testing were at around 0.6 percent in Japan, but this figure does not deviate significantly from that of other countries. It is true that in some cases there was a delay in conducting tests even when physicians requested PCR testing for their patients. Therefore, in preparation for a potential second wave of COVID-19, testing capacity is being strengthened so that it can be done without any delay when physicians determine that testing is necessary.

Critics also say that the low number of PCR tests may lead to overlooking some of the actual deaths from COVID-19. However, given Japan’s universal health care system, PCR testing is undertaken for almost all cases of severe pneumonia that result in death. Furthermore, almost all health care facilities perform a CT scan when they suspect COVID-19, based on nationally shared criteria in line with WHO recommendations.

There is a higher number of CT scans per million people in Japan than in other comparable countries (111 in Japan, compared to 11 in France, 38 in South Korea, and 44 in the United States). Thus, it is unlikely that COVID-19 cases that resulted in death were overlooked. In fact, at least until the end of April 2020, excess mortality in Tokyo was on a downward trend.

As indicated above, although testing operations in Japan can be explained as scientifically pragmatic and sound, people seem to criticize them simply because they are unique. This phenomenon is happening nationally and globally, and it is echoed in the case of Sweden, which adopted a mitigation strategy as opposed to a containment strategy.

Furthermore, the highly simplified discourse about PCR testing is easier for the general public to understand. However, testing is only one part of comprehensive crisis management activities, and a discussion on how to position testing operations within an overall exit strategy is needed.
The Japanese government has already lifted the state of emergency.

At this point it is necessary to develop a stepwise approach from the end of the state of emergency to a final exit strategy. There is an increasing need for numerical indicators that define a “new normal” under COVID-19, and how to optimize testing operations to clarify these numbers, rather than being distracted by the mere volume of tests.

After all, the simple number of tests performed is not necessarily linked directly to one of the most important outcomes, namely mortality — that is to say, saving lives — as has been proven in Japan so far.

Haruka Sakamoto, MD, MPH, is a primary care physician and assistant professor at the Department of Health Policy and Management, Keio University. She got her M.D from Sapporo Medical University and worked as a physician at St Luke’s International Hospital in Tokyo for several years


Comment(s) Write comment

Trackback (You need to login.)