Japan’s Ministry of Health, Labour and Welfare said the week to Oct 4 (2026 Week 40) saw 42,320 influenza cases reported by nationwide sentinel medical institutions, about 1.6x the prior week and roughly 7.3x year-ago. Average cases per sentinel site were 11.35. National influenza activity reached the advisory level for the first time this season.

2026-10-09

Japan’s Ministry of Health, Labour and Welfare said the week to Oct 4 (2026 Week 40) saw 42,320 influenza cases reported by nationwide sentinel medical institutions, about 1.6x the prior week and roughly 7.3x year-ago. Average cases per sentinel site were 11.35. National influenza activity reached the advisory level for the first time this season.