Overview
- National surveillance for Sept. 22–28 counted 4,030 patients at roughly 3,000 sentinel clinics, averaging 1.04 per site and surpassing the epidemic threshold.
- The health ministry issued the nationwide designation after 15 prefectures topped one patient per reporting site.
- Okinawa showed the highest incidence at 8.98 patients per site, followed by Tokyo at 1.96, Kagoshima at 1.68, and Fukuoka at 1.55.
- Several prefectures reported very low activity, led by Tottori at 0.03 per site, with Akita, Iwate, and Tokushima also low.
- The announcement comes earlier than Japan’s typical December–March flu season, after last season peaked in late December and extended into April.