South Korea’s national police agency has deployed some 8,500 officers (link in Korean) nationwide, in a race against time to identify people who visited nightlife venues in Seoul after the emergence of a cluster of Covid-19 cases linked to a man who went clubbing there. In a sign of how urgent the situation is, Seoul mayor Park Won-soon issued a stark warning yesterday: “If Seoul falls, the country falls.”
The number of cases traced to bars and clubs in the capital’s Itaewon district, in the vicinity of a large US military base, has swelled to 101 today, according to the Seoul metropolitan government—nearly double the count of 54 yesterday. The Itaewon cluster is now the largest in the country, surpassing the 97 cases connected with a call center in Seoul in March.
The latest cluster first emerged after it transpired that a 29-year-old man, who tested positive for the coronavirus on May 6, had gone partying at three different clubs in Itaewon the evening of May 1 and into the early hours of the next day. By Saturday (May 9), Seoul had ordered more than 2,000 clubs and bars to close in a bid to curb the outbreak.
Seoul is now tracking down some 11,000 people who had visited the area, identified through cellphone data, and has sent text messages urging them to get tested. Credit card transaction data also provided a list of 500 people who were in the area during the affected period, according to the mayor. Around 7,000 people linked to the Itaewon cluster have been tested as of yesterday, according to health authorities. Police are trying to track down about 2,000 people who remain unidentified out of a list of more than 5,500 people who visited the affected Itaewon clubs during the period in question. Those who have been identified have already been interviewed by investigators or been sent text messages.
Stringent contact tracing, as well as aggressive testing, have been key to Korea’s successful response to the pandemic. As health authorities laid out in a detailed playbook (pdf) on how the country flattened its curve, citizens have been encouraged to record their location data using Google Map’s timeline function, which they can then share with contact tracers if necessary. A contact tracing platform, launched in March, compiles data from three major telecommunications companies and 22 credit card companies, and can trace a case in as little as 10 minutes.
The Itaewon cluster comes just a few weeks after Korea unveiled new guidelines for a new normal of “everyday quarantine,” designed to allow the country to resume social and economic activities while minimizing the risks of a resurgence of cases. The speed at which the Itaewon cluster has grown demonstrates the delicate and risky challenge of reopening economies before a coronavirus vaccine is developed, and is an augur of the hyper-vigilance with which governments will have to pursue a “suppress and lift” policy in order to keep the transmission rate below the critical threshold of one.
The crowded indoors conditions of bars and clubs likely heighten the risk of community spread. A paper by Korean health officials, published last month, found that SARS-CoV-2 can be “exceptionally contagious in crowded office settings such as a call center.” Seoul’s city government announced today that air conditioned buses will be allowed to keep their windows open as a precautionary measure against the coronavirus.
Korea’s approach of aggressively tracing thousands of people linked to the latest cluster without resorting to strict lockdowns contrasts with how China, another country that has managed to keep the number of infections contained, is dealing with a resurgence of cases. After Shulan, in northeastern Jilin province, reported 11 domestically transmitted cases over the weekend, authorities immediately put the small city on partial lockdown. It follows a similar tactic employed in the northern city of Harbin, which was locked down in late April after several dozen cases were reported. And Wuhan, the city at the center of China’s outbreak, plans to test all 11 million of its residents after a cluster of six cases emerged from a single residential complex between Sunday and yesterday.