The number of hospitalized patients with COVID-19 in South Korea has jumped three-point-five fold in the past four weeks.

According to the Korea Disease Control and Prevention Agency(KDCA) on Friday, COVID-19 hospitalization increased from 63 in the fourth week of June to 225 in the third week of July.

By age, people over 65 years old accounted for 64-point-nine percent of the hospitalized cases.

The detection rate of COVID-19 is also on the rise as it stood at 17 percent as of the third week of this month, up ten-point-six percentage points from last month.

The KDCA explained that increased use of air conditioners during the summer combined with the lack of indoor ventilation creates an environment where respiratory infections are more likely to spread, while the summer travel season leads to increased human contact.