At least 10 COVID-19 cases with unknown transmission routes were reported Wednesday among participants of the massive Aug. 15 rally held in central Seoul, a development much feared by South Korea’s health authorities struggling to stop a resurgence of the coronavirus. 

The rally drew tens of thousands of people from all over the country and tracking them down appears to be a daunting task.

Korea saw 297 new COVID-19 cases – including 283 transmitted locally -- Wednesday, the largest daily increase since early March, according to the Korean Centers for Disease Control and Prevention.

“Within less than one week since Aug. 15, Korea reported more than 1,000 cases. This is evidence that community spread had been underway since early August and, if we contain it even a day late, a large-scale outbreak could take place,” Kwon Jun-wook, the KCDC deputy director, said at a briefing.

Taking the risk of further spread of the coronavirus seriously, authorities see this week as “critical” in their efforts to prevent the outbreak in the Seoul metropolitan area from spiraling nationwide. Their main goal is to trace and test those who have possibly been exposed to the virus at the Sarang Jeil Church and at the rally to minimize secondary transmission, Kwon said.

The number of cases linked to the anti-government rally and the Sarang Jeil Church is feared to further rise, as some 166 people from the church tested positive for the virus on Wednesday, bringing the total number of cases traced to the church to 623 so far.

The church in northern Seoul become the source of the second-largest cluster of infections in Korea to date, following the Shincheonji Church of Jesus from which 5,214 cases were reported from the country’s first peak in February and March.

At least 50 cases of secondary transmission linked to the Sarang Jeil Church were confirmed as of Wednesday, with the virus having spread to at least 11 establishments including call centers, offices, social welfare facilities and other religious facilities across the country. An epidemiological inspection is underway into 114 establishments in connection with the church-related cases. 

The government called on anyone who has visited the church since July 27, come into contact with church members, as well as anyone who has attended the Aug. 15 rally to be tested for the coronavirus regardless of symptoms.

In a worrying sign, the 10 cases from the Aug. 15 rally are not connected to the Sarang Jeil Church, whose members also attended the rally in large numbers, according to the KCDC. The epidemiological inspection into transmission routes is underway.

The KCDC’s deputy director reiterated his call for members of the public to adhere to the government’s safety guidance and its contact-tracing and testing efforts, warning against “fake news” on social media that is undermining the credibility of the health agency and its COVID-19 testing.

For the next two weeks, residents in the Seoul Metropolitan area are advised to stay indoors as much as possible except for necessary reasons – commuting, buying necessities and visiting hospitals.

The number of new cases has been in the triple digits for six days straight, after surging to 103 on Friday. Wednesday’s daily tally is the highest since March 8, when the country reported 367 COVID-19 cases.

Of the locally transmitted cases, the overwhelming majority were registered in the densely populated Greater Seoul area -- 150 in Seoul and 94 in Gyeonggi Province, which surrounds the capital.

Nine cases were reported in Busan, eight in Incheon, five in Gangwon Province, four in Gwangju, and three each in North Gyeongsang Province and South Chungcheong Province. Two cases were registered in Daegu, two in South Jeolla Province, and one each in Sejong, North Jeolla Province and North Chungcheong Province.

Starting Wednesday at midnight, tightened social distancing rules came into effect in the Greater Seoul region -- including Gyeonggi Province and Incheon -- to control the sprawling COVID-19 outbreak.

In-person gatherings and events with more than 50 people indoors or 100 people outdoors are banned. Some 12 types of businesses will be closed -- including nightclubs, karaoke rooms, buffet restaurants and internet cafes, which are deemed high-risk -- as well as indoor public facilities.

In the wake of a surge in COVID-19 cases traced to churches, in-person worship services and church-related gatherings in the Seoul metropolitan area -- home to some 25 million people -- will be prohibited.

Given the two-week COVID-19 incubation period, authorities believe the impact of the toughened social distancing campaign will begin to be felt in late August or in early September, Kwon said.

Meanwhile, only one-third of students will be allowed in classrooms at kindergartens, elementary and middle schools and two-thirds at high schools across the country to reduce crowdedness, according to the Ministry of Education.

As of Wednesday, 689 kindergartens and schools nationwide were temporarily closed due to the spread of the coronavirus. Some 40 percent of the cases involving students and teachers were reported for the past week.

Of Wednesday’s 14 imported cases, 12 were identified while the individuals were under mandatory self-quarantine in Korea, while two were detected during the quarantine screening process at the border. Twelve of the newly diagnosed people were foreign nationals. Eight were from Asia, two were from Europe and four from the United States.

So far, 14,006 people, or 87.22 percent, have been released from quarantine upon making full recoveries, up 72 from a day earlier. Some 1,746 people are receiving medical treatment under quarantine. Twelve people remain in serious or critical condition.

The number of deaths stays unchanged at 306, with the overall fatality rate at 1.91 percent -- 2.25 percent for men and 1.62 percent for women -- as of Wednesday. The fatality rate is 23.97 percent for those in their 80s or over and 8.43 percent for those in their 70s. 

The country has carried out 1,715,064 tests since Jan. 3, with 31,002 people awaiting results as of Wednesday.

(laeticia.ock@heraldcorp.com)