Influenza, which took off relatively early this year, is spreading rapidly, particularly among children across South Korea.

A Korea Disease Control and Prevention Agency(KDCA) survey released Friday showed that 22-point-eight out of every one-thousand outpatients at 300 medical facilities nationwide between October 26 and November 1 were suspected flu cases.

The latest tally was a 67-point-six-percent jump from the 13-point-six for every one-thousand tallied a week earlier.

The proportion among children is higher: 68-point-four per one-thousand among those aged 7 to 12, 40-point-six among one- to six-year-olds, and 34-point-four among 13- to 18-year-olds.

Authorities advised those 65 and older, expectant mothers and children aged six months to 13 years to get vaccinated free of charge under the national vaccination program.