South Korea's disease control agency said Sunday the level of the COVID-19 virus in wastewater has nearly doubled in just a week, following a surge in infections during the summer vacation season.According to the Korea Wastewater Surveillance program, run by the Korea Disease Control and Prevention Agency (KDCA), the average concentration of the virus at local sewage treatment plants reached 47,640 copies per milliliter during the second week of August.It marked a sharp rise from the 24,602 copies per milliliter recorded the previous week.The data is based on the levels of the COVID-19 virus in water treated by 84 wastewater plants across the country.The KDCA has been using the method since April last year to assess the number of COVID-19 patients within communities."The project aims to track the trend in the level of COVID-19 virus in wastewater, which has been rising recently," a KDCA official said.Meanwhile, the number of newly hospitalized COVID-19 patients in South Korea reached 1,359 during the second week of August, increasing sharply from 878 a week earlier.Source: Yonhap News Agency