COVID-19 transmission occurs despite using separated spaces

The number of confirmed cases related to clubs in Itaewon, Seoul has increased to 153 as of Friday, and secondary and tertiary infections have occurred in succession, putting routine quarantine in jeopardy. The confirmed case from Hongdae in Seoul, whose route of transmission was unknown, has been found to have contracted COVID-19 when he visited a karaoke that a confirmed patient from an Itaewon club had visited. At another karaoke, a person who used a different singing room from the one used by an infected person, contracted the virus in a case of tertiary infection. At the Seoul Detention House located in Uiwang, Gyeonggi Province, one correctional officer has tested positive, causing the court to shut down and postpone court hearings.

According to epidemiological surveys by the quarantine authorities, the Hongdae confirmed patient contracted the virus when he used the same singing room at a karaoke in Seoul’s Gwanak district three minutes after a confirmed patient who had visited a club in Itaewon used. At another karaoke in Seoul’s Dobong district, two people used separate singing rooms that used the same ventilation system, which resulted in another case of tertiary infection. “Countless droplets are made when singing at a narrow space, which increases the chance for the virus to spread or contaminate corridors or common spaces,” said a quarantine official, while downplaying the probability of transmission through the ventilation system. Nevertheless, the authorities will have to conduct additional epidemiological investigation to dispel public concern in summer when air conditioning use will increase.

While tracking the movement of people who had visited clubs in Itaewon was delayed, a suspected case of quaternary infection has occurred. A correctional official from the Seoul Detention House who visited the karaoke in Seoul’s Dobong district tested positive on Friday, setting off alarm on quarantine at the detention facility. The Seoul courthouse complex that was visited by the official was also shutdown on Friday. A detention house where narrow closed spaces are packed with a large number of people provides a perfect environment for COVID-19 to spread easily. Thorough countermeasures should be put in place to prevent the environment to become an amber for mass infections.

Of 5,500 visitors to the five clubs in Itaewon, only 4,300 people have received diagnostic testing as of Friday, which increases concern over a possible surge in multi-stage transmissions. The quarantine authorities judge that this weekend will be the watershed for multi-stage transmissions and has urged people to refrain from visiting closed and narrow facilities and attend large gatherings. The authorities should also reflect upon whether they eased quarantine guidelines too early despite successive warnings that clubs, bars, karaokes, and PC cafes could provide breeding ground for mass infection. An alarm has been set off over the routine quarantine system, and the authorities should double-check whether there are any loopholes in the quarantine guidelines.