[Yonhap]
[Yonhap]

Influenza is spreading rapidly across Japan ahead of the winter season, with the number of patients jumping nearly 1.6 times in a single week and the national average surpassing the "Caution" threshold for the first time this season. Schools and childcare facilities have been closing classrooms and suspending operations in response.

The outbreak coincides with a surge in Korean tourists visiting Japan, driven by the yen's prolonged weakness. About 850,000 Koreans visited Japan in August alone — more than any other nationality or region. Air passenger traffic between South Korea and Japan has risen more than 20 percent this year compared with last year, with the lower cost of travel fueling demand.

According to Japan's Ministry of Health, Labour and Welfare, a total of 42,320 flu cases were reported at designated medical institutions nationwide during the week of Sept. 28 to Oct. 4.

The average number of patients per medical institution rose to 11.35 — up from 7.17 the previous week and more than seven times the 1.56 recorded during the same period last year. Japan generally treats a figure above 10 patients per institution as the "Caution" level.

By region, Okinawa recorded the highest rate at 37.07 patients per institution, exceeding the alert threshold of 30. Saitama followed at 19.66 and Chiba at 18.72. Tokyo and Kanagawa both exceeded 15, reflecting rapid growth in the greater Tokyo area. Patient numbers rose week-on-week in 44 of Japan's 47 prefectures.

This year's flu season got off to an unusually early start. Japanese health authorities declared a nationwide flu epidemic on Aug. 28 — the second earliest on record since tracking began in 1999. Flu in Japan typically peaks between December and March.

Cluster infections at schools and childcare facilities are also increasing. From Sept. 28 to Oct. 4, 937 kindergartens, childcare centers, and elementary, middle and high schools nationwide implemented full or partial closures due to flu symptoms — more than four times the 209 facilities that did so during the same period last year.

The Japanese government is accelerating its winter preparedness in response to the faster-than-usual spread. The Ministry of Health, Labour and Welfare plans to supply about 46.69 million rapid flu test kits and antiviral medications for about 39.95 million people this winter — a significant increase from last year.

Authorities are also urging vaccination alongside basic infection-prevention measures such as handwashing and ventilation. Mask-wearing is recommended when visiting crowded places or medical facilities.

Flu typically causes sudden high fever, headaches, muscle aches and fatigue. Children, the elderly and people with chronic conditions face a higher risk of complications, including pneumonia.

The outbreak overlaps with a period of high travel demand for Japan. The won-yen exchange rate fell to around 800 won per 100 yen this year, and currency exchange volumes surged alongside travel bookings. In July, the five major South Korean banks converted a combined 31.5 billion yen ($199 million) — the highest monthly volume in 19 months.

Air passenger traffic between South Korea and Japan reached about 21.3 million in the January–August period, up 20.3 percent from the same period last year. About 850,000 Korean tourists visited Japan in August alone.

Health officials say travelers do not need to cancel trips to Japan because of the flu outbreak. However, given the rapid rise in cases in Tokyo and the surrounding metropolitan area, those planning to depart soon are advised to check local conditions and take basic precautions against infection.

Flu vaccines do not provide immediate immunity after injection, so health authorities recommend getting vaccinated before the winter season peaks. Travelers who develop fever, severe body aches or a cough during their trip are advised to rest rather than push through their itinerary, and to seek medical attention locally if needed.

Japan's flu season this year began several months earlier than usual, and the national average had already exceeded the "Caution" level by early October. Health authorities are closely monitoring whether the upward trend will continue as the peak winter season approaches.


rainbow@heraldcorp.com