Japan saw a record 64.39 influenza patients per clinic on average in the final week of December, the health ministry said Thursday, confirming the highest number of reported cases since ministry records began in 1999.

In the week through Dec. 29, there were a total of 317,812 reported cases of the flu, which is nearly three times the number from the same period in 2023. The average number of cases per clinic jumped from 42.66 the week before.

The number of patients has been on the rise across the nation, with all 47 prefectures reporting an increase from a week earlier.

Oita Prefecture saw the highest number of cases, averaging 104.84 cases per clinic, with Kagoshima and Saga coming in next with 96.4 and 94.36 cases respectively.

In 43 prefectures, infections have reached the “warning level,” which is declared when there is an average of 30 cases per clinic or more.

This has led to cancelations at schools and other institutions around the nation, with classes being canceled or full shutdowns at a total of 1,838 schools, day care centers and kindergartens — including 1,200 elementary schools, 391 middle schools and 135 high schools.

From September to December, 11,800 patients had been hospitalized with the flu around the country, with the majority being patients over the age of 60.

As numbers continue to rise, the health ministry is urging people to wear masks and thoroughly wash their hands to prevent infections.