Flu “alert” level approaches in Japan as cases rise 1.5-fold from previous week

From The Kobe Shimbun

September 29 2026

TOKYO – The Health, Labor and Welfare Ministry said Monday that the number of influenza cases reported by around 3,000 designated medical institutions nationwide between Sept. 14 and 20 averaged 8.48 per institution. The figure was 1.53 times higher than the previous week, continuing an upward trend and approaching the “alert” level of 10 cases per institution.

A total of 31,428 influenza cases were reported during the period. By prefecture, Okinawa recorded the highest average at 26.27 cases per institution, followed by Tokyo at 15.21, Aichi at 15.12 and Kanagawa at 14.71. The figure exceeded 1 case per institution—the benchmark indicating the start of an influenza outbreak—in 46 of Japan’s 47 prefectures, with Miyazaki the sole exception.

Schools and other educational institutions reported 19 closures, 171 grade-level closures and 870 class closures.