The number of suspected influenza cases in South Korea has surged to a five-year high in the second week of December, the Korea Disease Control and Prevention Agency said Friday.

The rate of patients exhibiting symptoms suggestive of influenza per 1,000 outpatients for the week of Dec. 3-9, stood at 61.3, up 26.1 percent from the previous week. This is the highest figure since 2019.

The younger age groups have been more likely to have suspected flu with 120.1 per 1,000 outpatients aged 7-12 and 133.4 per 1,000 outpatients aged 13 to 18.

Korea's threshold for considering the spread of seasonal flu an epidemic is 6.5 per 1,000 outpatients, according to the KDCA.

Flu vaccination is strongly recommended, the KDCA stressed. “The flu vaccine is generally considered to be 70-90 percent effective in preventing the illness. The flu vaccine is strongly recommended for vulnerable people, including pregnant women, people aged 65 and older, and children aged between 13 or under,” an official from the KDCA said.

“Personal hygiene practices such as proper handwashing, proper etiquette for coughing, and wearing a mask should be followed,” KDCA Commissioner Jee Young-mee said.

The KDCA said it was mulling additional stockpiling of antiviral drugs for flu. The KDCA earlier supplied 315,000 doses of antiviral drugs, including Tamiflu, to the market in November.