Got flu? You’re not alone, whole of Asia is in its grip and Japan has declared it a national epidemic

Health authorities in Japan have declared a nationwide influenza epidemic after cases surged five weeks earlier than expected, marking the country’s second-earliest outbreak in two decades.

More than 4,000 people were treated for flu between September 22 and 28, equating to an average of 1.04 patients per monitored medical institution, crossing the threshold for an epidemic. The number rose to over 6,000 between September 29 and October 5, with an average of 1.56 patients per institution, more than double the 0.77 recorded during the same period last year.

From September 22 to October 3, 135 schools and childcare centres closed nationwide, times higher than last year’s count for the same period. Twenty-eight of Japan’s 47 prefectures reported an increase in flu cases, with Okinawa recording the highest patient-to-institution ratio.

Flu cases rising across Asia

Japan’s outbreak reflects a broader regional trend, with flu cases also rising in Singapore, Thailand, and India in recent weeks. In northern India, the spread of the H3N2 virus—a descendant of the strain that caused the 1968 Hong Kong flu pandemic—has become a growing concern. Dr. Martin Beer, vice president of Germany’s Federal Institute for Animal Health (Friedrich Loeffler Institut), told DW News that this particular strain combines human and avian influenza viruses.

The influenza virus, which includes four types—A, B, C, and D—causes seasonal outbreaks mainly through types A and B. According to the US Centers for Disease Control and Prevention (CDC), while influenza and the common cold share similar symptoms, the latter can be triggered by various other viruses, including rhinoviruses.

The surge in flu cases across Asia, coupled with earlier outbreaks in Europe, has prompted some medical experts to warn that influenza may be evolving to spread faster or appear earlier than before, signalling a potential shift in global infection patterns.