TOKYO (Kyodo) -- The number of influenza patients reported at designated medical institutions across Japan at the end of the year hit the highest level since comparable data became available in 1999, the Japanese government said Friday.

Across roughly 5,000 institutions, 317,812 patients had been reported in the week through Dec. 29, averaging 64.39 people per facility and surpassing the warning level of 30, according to the Ministry of Health, Labor and Welfare.

It marked the 10th consecutive week of increase and a 1.51-fold rise from the week prior, and there were shortages of some of the medications used to treat influenza.

Patients increased in all 47 prefectures, with Oita Prefecture in southwestern Japan recording the most, averaging 104.84 people per facility. The lowest was Okinawa Prefecture, southern Japan, averaging 24.3 people per facility.