Number of influenza patients decreased by 3.18 compared to the previous week (per medical institution). By prefecture, the number was 29.05 in Niigata, 29.04 in Toyama, 27.63 in Yamagata, 25.54 in Ehime, and 24.31 in Hokkaido, making 39 prefectures the most.
"type B" influenza is the most common at 86% of cases, according to an analysis of viruses detected in the past five weeks.