Two female workers entertaining men at a large hostess bar in southern Seoul recently tested positive for the new coronavirus, raising concerns about mass infections at nightlife locations.

About 100 male customers and staff workers of the bar are said to have been exposed to the workers.

First of all, it is surprising that hostess bar business was booming even when most people were enduring the inconvenience of social distancing voluntarily.

The outbreak at the bar raises concerns that nightlife infections may revive the spread of the virus, which has been waning. The chance of the virus surging again may have been escalating at bars and clubs undetected, while the nation has been focusing on other high-risk facilities such as hospitals, churches and convalescent homes. It is as if public health authorities are playing whac-a-mole. The authorities must be more proactive.

Popular hang-outs such as Gangnam and Hongdae streets are still crowded with youngsters at night. Young people line up to get into nightclubs. Wariness of the disease seems to be loosening up as the number of newly confirmed COVID-19 cases stayed around 50 for the fourth day in a row. The time to relax has not yet come.

The booming business of bars and nightclubs frequented by some of those in their 20s and 30s reflects their perception of the disease as being a minor illness, like a bad cold.

In Korea, 27 percent of confirmed COVID-19 infections have occurred to those in their 20s. The figure is six times higher than that of those in their 80s, but there is no death of the virus yet among 20-somethings. It is true that young people suffer mild symptoms and recover even if they contract the virus disease.

The problem is that those young people who are unaware that they are infected because of moderate symptoms may spread the virus silently and unpredictably on public transportation systems and at crowded places.

A while ago, the head of the World Health Organization warned young people that they were “not invincible.” Youngsters must keep the warning in mind and cooperate with social distancing more actively.

When authorities recently extended reinforced social distancing rules by two more weeks, they advised bars and clubs to close, asking them to abide by distancing rules completely if they remain open. But it is questionable whether the advice is enough to ease concerns. According to a two-week nationwide survey by the Central Disaster and Safety Countermeasures Headquarters, about a quarter of 30,380 nightlife locations were found to have violated the guidelines.

Bars and nightclubs are highly enclosed spaces. They have few windows. It is hard to keep social distancing. People are very close to one another and talk without wearing masks. Employees and customers tend to avoid revealing the truth about their work or visits there.

Bars and clubs are not likely to comply with disinfection rules such as checking temperatures of guests, drawing up a list of them, and maintaining physical distance. Some hostess bars may even try to keep running their businesses in secret. Measures stronger than advice are needed.

Prime Minister Chung Sye-kyun instructed related ministries to effectively shut businesses when they violate the rules. The government plans to enforce an intensive crackdown at night on weekdays as well as weekends.

Seoul on Wednesday issued an order for an essential suspension of business until April 19 for 422 hostess bars and clubs. It is a belated but right move. Business setbacks are inevitable but they must cooperate. To maximize the effect of disinfection, however, the same measure should be extended nationwide. The central government needs to do more than giving advice and imposing sanctions for rule violations.

Above all, it is most desirable for the young generation to practice social distancing more actively for the safety of their community. Unless everybody follows the rules at the same time, the epidemic will hardly be dispelled.