The number of norovirus patients in the country has hit a ten-year high, raising concerns over an epidemic.

According to the Korea Disease Control and Prevention Agency(KDCA) on Monday, there were 469 norovirus patients at 210 medical facilities during the fourth week of January, a ten-year high.

Fifty-one-point-four percent of the patients were children aged up to six years.

Symptoms of the illness for which there is no vaccine include vomiting, diarrhea, abdominal pain, chills, and fever.

The number of patients infected with the rotavirus, involving similar symptoms, also doubled compared to last year, standing at 123 as of the fourth week of January.

Rotavirus vaccination is included in the country's free vaccination program for children.