South Korea has reported an eight-fold jump in viral infections in four days to 433 on Saturday, most of them linked to a church and a hospital in and around the nation’s fourth-largest city.
Health workers have scrambled to screen thousands of worshippers, while the country has also reported its third death from the virus, a man in his 40s who was found dead at home and posthumously tested positive.
Virus patients with signs of pneumonia or other serious conditions at the Cheongdo hospital were transferred to other facilities, 17 of them in critical condition, vice-health minister Kim Gang-lip told reporters.
There is concern South Korea’s death toll could grow, with Mr Kim saying the outbreak had entered a serious new phase.
But he still expressed cautious optimism it can be contained to the region surrounding Daegu, where the first case was reported on Tuesday.
Of the 229 new cases in South Korea, 200 are from Daegu and nearby areas.
By Saturday morning, the city of 2.5 million and surrounding areas counted 352 cases, including two fatalities in the Cheongdo hospital.
Both patients had pneumonia.
The central government has declared the area a “special management zone” and is channelling support to ease a shortage in hospital beds, medical personnel and equipment.
While some experts say the virus has started to spread nationwide, pointing to a number of infections in Seoul and elsewhere that were not immediately traceable, Government officials remained hopeful of containing the outbreak.
“Although we are beginning to see some more cases nationwide, infections are still sporadic outside of the special management zone of Daegu and North Gyeongsang Province,” Mr Kim said during a briefing.
He called for maintaining strong border controls to prevent infections from China and elsewhere from entering South Korea.
Nationwide, the numbers told of a ballooning problem. There were 20 new cases reported on Wednesday, 53 on Thursday and 100 on Friday.
Around 230 of those have been directly linked to a single house of worship, a Daegu branch of the Shincheonji Church of Jesus, where a woman in her 60s attended two services before testing positive for the virus.
Officials are also investigating a possible link between churchgoers and the spike in infections at the Cheongdo hospital, where more than 110 people have been infected so far, mostly patients on a mental illness ward.
Health officials were screening some 9,300 church followers and said 1,261 of them have exhibited cough and other symptoms.
Among them, four had travelled abroad in recent months, including one to China, although that trip came in early January and was not near Hubei.
All 74 sites operated by the Shincheonji Church have been closed and worshippers have been told to instead watch services online for a sect whose leader claims to be an angel of Christ but who is dismissed by many outsiders as a cult leader.
Its teachings revolve largely around the Book of Revelation, a chapter of the New Testament known mostly for its apocalyptic foreshadowing.
Health and city officials say the woman who first tested positive had contact with some 1,160 people, both at the church, a restaurant and a hospital where she was treated for injuries from a car accident.
But officials say it is unlikely the woman set off the chain of infections, and that she was probably just the first person to be detected in an area where the virus was circulating in the population.