News On Japan

COVID-19 patients with no symptoms likely to stay that way: Japanese researchers

Jun 15, 2020 (Japan Times) - What are the odds COVID-19 patients with no symptoms could later develop them?

Quite slim, according to a recent study led by a group of researchers in Aichi Prefecture, who have discovered that asymptomatic coronavirus patients tend to recover within nine days of having their infections confirmed via polymerase chain reaction (PCR) tests.

The findings, involving a study on how the disease developed in 90 people without symptoms who contracted the disease aboard the Diamond Princess cruise ship, were published Friday in the New England Journal of Medicine and showed that only 11 people without symptoms would go on to develop them later.

“In this cohort, the majority of asymptomatic infected persons remained asymptomatic throughout the course of their infection,” a team led by Yohei Doi, a doctor and professor of the department of infectious diseases at Fujita Health University wrote in the report.

The results showed that nearly half of the patients were cleared of the virus within nine days after first testing positive for COVID-19, while 90 percent of people recovered within 15 days. The findings also showed that most patients were unlikely to recover within five days after the initial positive test.

Based on the findings, the health ministry on Friday revised its guidelines for hospitalization of COVID-19 patients. It is now advising that patients who test negative twice over six days after the initial positive test should be discharged.

Fujita Health University’s Okazaki Medical Center took in 128 people from the virus-hit Diamond Princess — 96 passengers who tested positive for the coronavirus but had no symptoms and 32 of their cabinmates who tested negative. All were between the ages of 9 and 77. In total, data on 90 patients without symptoms were available for analysis.

News On Japan
POPULAR NEWS

Large Typhoon No. 25 was moving northwest over waters south of Japan at 3 p.m. on September 19 and is forecast to strengthen as it approaches Kanto and the Izu Islands from September 20 through September 21, bringing the risk of torrential rain, violent winds and further damage in areas still recovering from last year's typhoon.

A black bear has been spotted near one of the most popular hiking trails on Mount Takao in western Tokyo, prompting authorities to urge visitors to take precautions ahead of the five-day Silver Week holiday and the approaching autumn foliage season.

Starbucks is considering selling a majority stake in its Japanese business, potentially valued at as much as $3 billion, or about 470 billion yen, as the U.S. coffee chain seeks to concentrate management resources on its struggling North American operations.

Japan's Halloween Jumbo Lottery went on sale nationwide on September 16, offering a combined top payout of 400 million yen for the first prize and its adjacent-number prizes.

A new top-tier "Supreme Class" offering fully private compartments above the level of Green Car service will debut on the Tokaido and Sanyo Shinkansen on October 1, with passengers able to experience the new seating at a demonstration booth at Shin-Osaka Station.

MEDIA CHANNELS
         

MORE Society NEWS

Anonymous and fluid criminal groups known in Japan as "tokuryu" are adopting increasingly elaborate tactics, including a scheme in which elderly victims are persuaded to hide cash inside refrigerators before thieves enter their homes, as authorities struggle to combat networks whose members often have no direct contact with one another.

A luxury mansion in Bangkok described as resembling a palace was being used as a base for a specialized fraud operation targeting Japanese people, with Thai authorities detaining 14 people, including four Japanese men.

Copper roofing has been stripped from Shinano-no-miya Shrine in Oshika Village, Nagano Prefecture, leaving the wooden structure exposed in the latest of a series of similar thefts reported at shrines across the prefecture.

A popular Tokyo nightclub hostess and influencer known as Yamatorino, who says she generated more than 200 million yen in sales during a single month, has been arrested on suspicion of possessing cocaine with her boyfriend at their home in Roppongi.

A second-year high school student was arrested at the scene after allegedly releasing tear gas spray inside a classroom at Osaka University of Commerce Sakai High School on September 16, leaving 24 students complaining of coughing, throat pain and other symptoms.

Police have arrested a 26-year-old man suspected of acting as a top-level planner in an anonymous, fluid criminal group known as a "Tokuryu," with investigators believing he was involved in a series of theft-related crimes in Kyoto and other areas between December 2025 and March 2026.

A 37-year-old man was arrested at Chubu Centrair International Airport after allegedly injuring a police officer who warned him about walking two toy poodles without leashes inside the airport complex.

The number of people aged 100 or older in Japan has exceeded 100,000 for the first time, reaching a record 107,677 as of September 1, according to the Ministry of Health, Labor and Welfare.