Flu cases trigger epidemic alert


The National Institute of Infectious Diseases has issued a flu epidemic alert after logging a countrywide surge in influenza patients.

The average number of patients at some 5,000 medical institutions regularly surveyed by the institute shot up to 34.44 in the week through Sunday from 24.81 a week before, breaking the alert level of 30, it said Friday.

The total number of patients for the week was estimated at 1.87 million, reflecting a jump of 550,000, the institute said. The uptick was especially sharp in the Kanto region and in Kyushu and Okinawa.