More than half of South Korea’s 51 million people live in the Seoul metropolitan area.
So far, 93 people have tested positive among the call center's employees and their families, Seoul Mayor Park Won-soon said Wednesday in a briefing broadcast over YouTube. The number could grow as tests are being done on more than 550 co-workers who worked on other floors of the Korea Building in Seoul's Guro district.
Health workers in white protective suits scrambled to sanitize the nearby Sindorim subway station, which is used by more than 404,000 commuters per day, according to Seoul Metro.
While most of the infected workers live in Seoul, some of them commute from nearby cities such as Incheon and Bucheon, raising concern about a broader spread through public transit.
Call center workers may be vulnerable because they work long hours in crowded and confined spaces, said Yoon Tae-ho, an official from South Korea’s health ministry.
Jung Eun-kyeong, director of South Korea’s Centers for Disease Control and Prevention, said it would be difficult to track infections if they spread to buses and subways. She said it’s “most critical” that public transit operators vigorously sanitize handles, bars and anything passengers frequently touch with the threat of local transmissions growing.
Park said Seoul is investigating the working conditions of more than 400 call centers in the city and will push employers to allow more employees to work from home. The mayor said authorities were responding actively to prevent the cluster from intensifying like South Korea's earlier clusters around the southeastern city of Daegu.
So far, all of the infections linked to the Korea Building have surrounded call-center employees who worked on the 11th floor. The building is also home to about 200 residents and hosts a wedding hall, a Starbucks coffee shop and the campaign office of Yun Kun-young, a confidant of South Korean President Moon Jae-in who is running in next month's parliamentary elections.
Yun, Moon’s former secretary for state affairs, tweeted that he and other members of his camp have been placed under self-quarantine, and that he tested negative for the virus.
“I was personally fortunate, but my heart is still heavy,” tweeted Yun, who will run in the Guro district. “Considering the (working) conditions of the call center, there could be more cases, and it’s a concern that infections are rising among Guro residents.”
His office didn’t answer calls for comment.
Jung said government officials are planning to create an anti-virus guideline for workplaces they see as vulnerable to infections, which aside from call centers also include karaoke rooms, internet cafes and gyms. While employers will possibly be pushed to let more workers work from home and spread out the working hours of those who come to the office, Jung avoided a straightforward answer when asked whether officials could shut down businesses if infections get out of control.
Most of South Korea’s 7,755 virus cases have been in Daegu and nearby areas. Many were connected to the local branch of the Shincheonji Church of Jesus, and in the past week, health authorities completed testing thousands of members of the church.
But while the outbreak has slowed in Daegu, infections have been steadily rising in the Seoul metropolitan area, which now counts around 400 cases.
Park has clamped down on public gatherings, banning rallies in major downtown areas in a city famous for its vibrant protest culture.
Lee Jae-myung, governor of Gyeonggi province, which surrounds Seoul, said Wednesday that he could issue an order to restrict religious gatherings if churches fail to cooperate with anti-virus efforts, such as screening followers for fever and ensuring that they are at least 2 meters (6.5 feet) apart during services.
South Korea's caseload is the fourth highest in the world after China, Italy and Iran. For most people, the virus causes mild or moderate symptoms, such as fever and cough, but severe illness is more likely among the elderly and those with existing health problems. More than half of the world's almost 120,000 people infected with the virus have recovered.
Much of South Korea’s anti-virus efforts has focused on isolating patients and tracing their contacts.
Health officials use personal data, including public transportation and credit-card records and smartphone GPS information, to track patients and their contacts. Details about where patients visited before their positive tests are quickly posted online and shared through smartphone alerts, an active response that some critics say raises privacy concerns and exacerbates panic.
Since Saturday, people under self-quarantine have been required to use a smartphone app that reports their health status and alerts officials if they leave their quarantine areas. Strengthened laws on infectious diseases impose one-year prison terms and fines for those who violate self-isolation.
Associated Press writer Hyung-jin Kim contributed to this report.