Tokyo issues rare second flu alert in same season as cases surge

Tokyo has issued an influenza alert for the second time this season, a first since records began in 1999, as infections have surged beyond the warning threshold again.

The Tokyo Metropolitan Government announced on Thursday that cases rose sharply in the week of January 26 to February 1. It had issued its first alert last November, lifted it in January, but reinstated it just a month later. The alert is triggered when over 30 cases are recorded at designated medical institutions and over 30 percent of Tokyo's population is in affected areas. In the latest data, nine out of 31 designated areas exceeded the threshold, covering 37.16 percent of the population.

Medical analysis indicates over 90 percent of recent cases are influenza B, marking a shift from the initial wave dominated by influenza A. Experts attribute the spread to prolonged cold weather keeping people indoors with poor ventilation, lowered immunity, and rapid transmission in communities and schools.

The outbreak has severely impacted education. From September 1 last year to February 1 this year, Tokyo recorded 6,522 group infection cases at schools and welfare facilities. A total of 4,224 kindergartens, elementary, and secondary schools were forced to close temporarily, a significant increase from 2,883 in the same period last year.

Tokyo health authorities urged the public to maintain good hygiene, wash hands frequently, wear masks, and seek medical attention and rest at home if symptoms like fever or sore throat appear to prevent further spread during the Lunar New Year period.