Unless he faints or cannot walk, administrative manager Peter Cha will report for work no matter what.

Calling in sick is frowned upon in South Korea, where "good work" equals long hours in the office, and workers fear that taking the day off would inconvenience their colleagues and create a bad impression. In any case, the country also lacks a proper sick leave system.

Observers say the social phenomenon known as noonchi - the art of gauging the situation around you and acting accordingly - combined with the deeply ingrained belief that no illness should keep one away from work, church, dance class, or attending a funeral, could have contributed to the rapid spread of the coronavirus in South Korea.

The country reported 7,979 cases and 72 deaths as of last Friday.

In the largest cluster of cases in Seoul, some call centre employees developed symptoms from late last month but continued to work until testing positive last week.

There are now at least 100 cases there, out of 207 employees hired by a call centre located in Sindorim in the south-west.

The severity of the situation has prompted the government to plan guidelines for cramped offices vulnerable to mass infections, and make recommendations such as allowing employees to work from home or go to work at staggered hours.

Home to a population of 10 million, Seoul has reported 225 cases of the coronavirus, making it the third-most infected area after Daegu city and North Gyeongsang province, both in the south-east. The numbers are growing as more clusters emerge.

The worst health crisis in South Korean history has called into question the lack of a proper sick leave system and the flippant attitude towards common illnesses such as the flu, as well as symptoms like fever and cough.

Unlike in places such as Australia, Switzerland and Singapore, where employees are entitled to take paid sick leave upon submitting a doctor's note, companies in South Korea tend to expect employees feeling unwell to see the doctor, get some medicine or an intravenous drip, and then return to work.

South Korean labour law guarantees at least 11 days of annual paid leave for workers, but when it comes to sick leave, the issue is not so clear.

Mr Park Dong-hak, a lawyer with labour law firm Hae Myung, told The Sunday Times that the Labour Standards Act and the Labour Relations Act "do not explicitly stipulate sick leave or vacations caused by personal illness".

So while civil servants are entitled to paid sick leave for common ailments, most companies will cover only major medical issues such as cancer or a broken leg.

Those who are sick and require a day or two of rest will have to use their own annual leave to cover their absence.

In an article titled "A country without paid sick leave", Hankyoreh newspaper said in May last year that only seven out of 100 companies with more than 10 employees offered paid sick leave.

Even if they were entitled to paid sick leave, very few employees would use it because "it all boils down to noonchi", said Mr Cha, the administrative manager.

"We have a comprehensive leave system, but we are unable to make good use of it due to social relationships and concerns about workplace hierarchy," the 36-year-old told The Sunday Times.

Mr Steve Kim, 50, has never reported sick in the past 27 years. His current employer, a government technology agency, allows three days of paid sick leave a month.

"I never felt I was so sick that I could not go to work," he said. "Noonchi was a reason in the past, now I'm too old for that. But it's good to know that we have paid sick leave, even though I've not used these welfare benefits before."

For Singaporeans who have worked in Korean companies, the difference in attitudes towards paid sick leave is glaring.

Sales support manager Kat Lim, 49, who used to work in a Korean company in Singapore, recalled how her then Korean colleagues complained about Singaporeans faking illness and abusing the leave system.

"They said Singaporeans love to take MCs, and that we should stop doing it because in Korea, people crawl to work even though they are sick," she said in an interview.

"We are entitled to 14 days of paid MC in Singapore, and we take it to prevent spreading germs in the office. But Koreans get praised for working hard when sick and being loyal to the company."

Some observers believe the situation in South Korea may change following the coronavirus outbreak as thousands of workers, for the first time in history, are now working from home out of fear of mass infections at the office.

Said Seoul National University law professor Lee Jae-min: "The regular Korean mindset is that the world would collapse if we stay at home instead of going to work. But now we know that nothing happens, and things are better if we stay at home. That's the silver lining of the coronavirus outbreak."

• Additional reporting by Kim Yeo-joo