Japan is grappling with a sharp rise in seasonal influenza cases, prompting health authorities to urge people to take heightened precautions as the year-end holiday period approaches.

Data that the health ministry released Friday highlights a troubling spike in infections. From Dec. 9 to 15, there were 94,259 cases of the flu reported across some 5,000 hospitals and clinics nationwide.

This brings the estimated total of cases nationwide to 718,000, more than double the figure recorded the previous week.