Japan has once again reached the influenza epidemic alert level

The Japanese Ministry of Health, Labour and Welfare released data on the 6th showing that after a period of easing, during the week of January 26 to February 1, the average number of influenza cases reported per designated medical institution across Japan reached 30.03, once again reaching the epidemic alert level for influenza nationwide. The latest data released by the Ministry on the same day indicate that from January 26 to February 1, over 3,800 designated medical institutions nationwide reported a total of 114,300 influenza cases, with an average of 30.03 cases per institution, surpassing the epidemic alert threshold of 30 cases. Due to the resurgence of influenza activity, 6,415 educational facilities across Japan suspended classes or partially suspended classes this week, with nearly 60% being elementary schools. Previously, during the week of November 10 to 16, 2025, Japan reached the influenza epidemic alert level, with an average of 37.73 cases reported per designated medical institution. In the following weeks, the average number of influenza cases per institution remained above 30, until the week of December 22 to 28, 2025, when it dropped to 22.77. The Ministry of Health, Labour and Welfare stated in early December 2024 that at that time, the vast majority of influenza cases in Japan were caused by a sub-branch K mutant of the H3N2 virus, which may be one of the key reasons for the rapid spread of influenza. Data also show that since the end of 2024, the proportion of influenza B virus infections among cases has increased. Experts believe that the sequential prevalence of these two viruses may be one of the reasons for the resurgence after the influenza activity subsides. (Xinhua)