Japan in the last week of December experienced the biggest influenza outbreak since comparable data became available 25 years ago, health authorities said Thursday.

The latest health ministry analysis of data gathered from 5,000 medical clinics showed that from December 23-29, 317,812 people were diagnosed with flu.

That is more than three times the 104,612 cases recorded in the same period in 2023, and the most for any week since records began in 1999, the ministry said.

Cases of flu often rise in the winter in Japan and elsewhere, but some countries have seen large jumps in cases recently including in France and Britain.

Australia logged more than 350,000 laboratory-confirmed flu cases last year -- dwarfing a previous high of 313,615 in 2019, according to its national diseases surveillance system.