South Korea has reported a sudden spike of 20 new cases of coronavirus infection, raising concerns about a potential "super spreader" who has already infected 14 people in a church.
This brings the total number of cases in the country to 51, sending alarm bells ringing as the government scrambles to strengthen quarantine measures to contain a possible community spread.
Epidemiological investigations showed that 14 of the new cases revealed yesterday attended the same church as the 31st patient, a 61-year-old Korean woman who developed a sore throat on Feb 8 and was diagnosed on Tuesday.
It is not clear how she contracted the virus as she had not travelled overseas recently and had no contact with the previous confirmed cases.
The woman, a native of the south-eastern city of Daegu, is known to have come into contact with 166 people, all of whom have been quarantined. These include her husband and two children.
The Korea Centres for Disease Control and Prevention (KCDC) said the woman was warded for 10 days from Feb 7 at Saeronan Oriental Hospital in Daegu. She was hospitalised after a car accident on Feb 6
As her injuries were minor, she left the hospital to attend a two-hour religious service at Shincheonji Church of Jesus on Feb 9, and again on Feb 16. She also had lunch with an acquaintance at a hotel buffet restaurant on Feb 15.
The cluster of 14 infections in the church includes men and women living in Daegu and the eastern Gyeongsangbuk province. Shincheonji Church of Jesus was founded in 1984 by religious leader Lee Man-hee, who has been accused of heading a cult.
The KCDC said yesterday it is planning to conduct tests for the entire church as a precaution, and that further investigation is needed to determine the source of infection and how it spread.
The health authorities have warned of a potential community spread, as experts attempt to trace how the new spate of cases could have occurred. At least four people who tested positive for the virus have no links to previous infections or any travel history.
But the authorities also called for calm, saying that it is still too early to judge if the situation is a full-blown outbreak.
As of yesterday, South Korea has tested 10,411 people for the virus, with 1,030 under quarantine. Sixteen people have been discharged after making a full recovery.