A screen capture of the website of the U.S. Embassy & Consulates in Japan is seen in this image. (Mainichi)

TOKYO -- The U.S. Embassy in Japan released a health alert on April 3 encouraging its citizens to return to the U.S. as soon as possible, saying that a lack of polymerase chain reaction (PCR) tests was making the present state of novel coronavirus infections in Japan hard to read.

The message was directed at U.S. citizens who wish to return to the United States, and those who live in the U.S. but are currently in Japan.

"The Japanese Government's decision to not test broadly makes it difficult to accurately assess the COVID-19 prevalence rate," the alert said. "While we have confidence in Japan's health care system today, we believe a significant increase in COVID-19 cases makes it difficult to predict how the system will be functioning in the coming weeks."

Providing its analysis of the current situation, the embassy wrote, "Over the past 72 hours, more than 650 individuals across the country have tested positive, an increase of approximately 200 cases per day ... A growing number of medical and political leaders across the country are expressing concern that a surge in cases is imminent."

It continued, "As compared to the number of positive cases and hospitalizations in the United States and Europe, the number of reported COVID-19 cases in Japan remains relatively low."

The alert further warned, "In the event of a spike in cases, U.S. citizens with pre-existing medical conditions may not be able to receive the medical care they have grown accustomed to in Japan prior to the COVID-19 pandemic."

The embassy also noted the falling number of available flights between Japan and the United States, saying: "As of April 3, only 11 percent of the pre-COVID-19 flight capacity from Japan to the United States remains in operation. While we cannot predict what will happen next, it is safe to assume that Japan's entry restrictions will further reduce flight availability in the near- and medium-term."

Rather than exhaustively carrying out PCR tests and obtaining a wider picture of the state of infections, the Japanese government's approach to the novel coronavirus has been to maintain care and secure medical facilities for those with severe symptoms, and focus on identifying clusters of infections. The policies have led to Japan continuing to conduct fewer PCR tests than many other countries.

(Japanese original by Shinichi Akiyama, Political News Department)