Aju Business Daily

SEOUL -- South Korean researchers have verified asymptomatic infections in an animal experiment using ferrets. The transmission of a new coronavirus began from the second day of infection, although ferrets showed no clinical symptoms such as high fever.

A joint animal experiment was conducted by Chungbuk National University's College of Medicine and the research institute of the National Medical Center, which found that the novel coronavirus was detected in blood and other bodily fluids as well as nasal secretions on the second day of infection.

Ferrets did not show any clinical symptoms but infection began in other ferrets living in the same area on the second day. The researchers began detecting clear symptoms such as high fever, coughing, and decreased activity on the fourth day.

South Korea's national fight against COVID-19 has been hampered by asymptomatic infections and the dynamic nature of COVID-19. In an outbreak that hit the Ministry of Oceans and Fisheries in the southern city of Sejong, health officials discovered 39 patients in an overall inspection from March 10 to 24, with 33 percent of them showing no symptoms, according to the Korea Centers for Disease Control and Prevention (KCDC).

In the southeastern city of Daegu, the epicenter of South Korea's epidemic, 4,258 believers of Shincheonji, a religious cult, have been infected with COVID-19. Of them, 3,222 members were found to have walked the streets without feeling symptoms at the incubation period.

KCDC officials have attributed a high rate of asymptomatic infections to the early and extensive screening of suspected cases. Another factor that has annoyed health officials was the re-infection of those who have been cured and discharged from isolation wards.

So far, 50 cases of re-infection have been discovered, KCDC director Jeong Eun-kyeong told a regular press briefing on Monday. An epidemiological survey should be conducted, but she suggested that the virus might have been reactivated as many were infected again in a very short period of time after they were discharged from hospital.