SEOUL, April 6 (Xinhua) -- A total of 51 South Korean people tested positive again for COVID-19 after they had recovered and been discharged from quarantine, the Korea Centers for Disease Control and Prevention (KCDC) said Monday.

The KCDC saw a higher possibility for the virus remaining in certain cells to be reactivated, rather than for people to be infected again, given that they retested positive in a relatively short period of time after being released from quarantine.

The patients here, who test negative twice with a 24-hour interval, are seen as having fully recovered and are allowed to be discharged from quarantine.

Of the total, 18 residents in Daegu and 17 in its surrounding North Gyeongsang province tested positive again.

The health authorities planned to send a team of investigators to conduct an epidemiological investigation into the cases.

Daegu, about 300 km southeast of the capital Seoul, has been the epicenter of the virus spread as the biggest cluster of infections was found in the city. The total number of infections in Daegu and North Gyeongsang province accounted for nearly 80 percent of the total.

In the latest tally, the country reported 47 more COVID-19 cases for the past 24 hours, raising the total number to 10,284.