Japan Enters Flu Season in Second-Earliest Start on Record, Okinawa Reports Highest Rate

TOKYO — Japan has officially entered its seasonal influenza epidemic period, marking the second-earliest start to a flu season since comparable records began in 1999, according to the country’s health authorities.

Data released by Japan’s Ministry of Health showed that approximately 3,000 designated medical institutions nationwide reported a total of 4,094 influenza cases during the week ending Aug. 23.

The average number of cases stood at 1.11 patients per medical institution, exceeding the benchmark of one case per facility used to indicate the beginning of the influenza epidemic season.

The unusually early start has prompted health authorities to encourage the public to take preventive measures as influenza activity increases across several parts of the country.

Okinawa Records Highest Influenza Rate

Among Japan’s prefectures, Okinawa in the south recorded the highest influenza activity during the reporting week, with an average of 4.43 cases per medical institution.

It was followed by Iwate and Aomori prefectures in northeastern Japan, which reported averages of 2.10 and 2.08 cases per institution, respectively.

The figures indicate that influenza activity is already occurring across geographically distant parts of the country, despite the season beginning considerably earlier than is typically expected.

Second-Earliest Flu Season Since Records Began

The latest figures make the 2026 influenza season the second-earliest recorded start in Japan since the current surveillance system began in 1999.

Excluding 2023, when influenza infections remained elevated throughout much of the year, the earliest recorded start occurred in 2009, when the national average exceeded the epidemic threshold during the week of Aug. 10–16.

The early arrival of influenza is significant because flu activity in temperate countries such as Japan has traditionally been associated more closely with the colder months.

However, influenza transmission patterns can vary from year to year depending on circulating virus strains, population immunity, travel and social activity, among other factors.

Health Authorities Urge Preventive Measures

With influenza activity already exceeding the national threshold, Japan’s health authorities are urging the public to take precautions to reduce the risk of infection and transmission.

Recommended measures include regular handwashing, wearing face masks when appropriate and receiving influenza vaccination.

Influenza is a contagious respiratory illness that can cause symptoms including fever, cough, sore throat, headache, fatigue and muscle aches. While many people recover without complications, the infection can lead to serious illness in vulnerable populations.

Older adults, young children, pregnant women and people with certain underlying health conditions may face a higher risk of developing severe complications.

Early Flu Season Highlights Importance of Surveillance

Japan operates a nationwide influenza surveillance system that collects reports from designated medical institutions to monitor infection trends and identify when disease activity exceeds established thresholds.

The latest data show that the national average has already crossed the level used to signal the beginning of the influenza season.

Continued surveillance will therefore be important in determining whether infections continue to rise and how widely influenza spreads across the country in the coming weeks.

With Japan entering its flu season unusually early, health authorities are emphasizing basic infection-prevention measures and vaccination as the country prepares for potentially higher influenza activity.

 

Source : Xinhua Thai News